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Intel® 855PM Chipset Platform
Design Guide
For use with Intel Pentium M and Intel Celeron M Processors
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May 2004
Revision Number 003
Document Number: 252614-003
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Information in this document is provided in connection with Intel products. No license, express or implied, by estoppel or otherwise, to any intellectual
property rights is granted by this document. Except as provided in Intel’s Terms and Conditions of Sale for such products, Intel assumes no liability
whatsoever, and Intel disclaims any express or implied warranty, relating to sale and/or use of Intel products including liability or warranties relating to
fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. Intel products are not intended
for use in medical, life saving, or life sustaining applications.
Actual system-level properties, such as skin temperature, are a function of various factors, including component placement, component power
characteristics, system power and thermal management techniques, software application usage and general system design. Intel is not responsible for its
customers’ system designs, nor is Intel responsible for ensuring that its customers’ products comply with all applicable laws and regulations. Intel
provides this and other thermal design information for informational purposes only. System design is the sole responsibility of Intel’s customers, and
Intel’s customers should not rely on any Intel-provided information as either an endorsement or recommendation of any particular system design
characteristics.
Intel may make changes to specifications and product descriptions at any time, without notice.
Designers must not rely on the absence or characteristics of any features or instructions marked "reserved" or "undefined." Intel reserves these for future
definition and shall have no responsibility whatsoever for conflicts or incompatibilities arising from future changes to them.
The Intel® Pentium® M processor, Intel® Pentium® M processor on 90nm process with 2-MB L2 Cache, Intel® Celeron® M Processor and Intel® 855PM
Chipset may contain design defects or errors known as errata which may cause the product to deviate from published specifications. Current
characterized errata are available on request.
Contact your local Intel sales office or your distributor to obtain the latest specifications and before placing your product order.
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*Other brands and names are the property of their respective owners.
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Intel® 855PM Chipset Platform Design Guide
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Contents
1.
2.
3.
4.
Introduction .................................................................................................................................19
1.1.
Terminology ...................................................................................................................19
1.2.
Referenced Documents .................................................................................................21
System Overview........................................................................................................................23
2.1.
Intel® CentrinoTM Mobile Technology Features..............................................................23
2.2.
Intel® Pentium® M Processor/Intel® Celeron® M Processor ............................................25
2.2.1.
Architectural Features ....................................................................................25
2.2.1.1.
Packaging/Power ............................................................................25
2.3.
Intel 855PM Memory Controller Hub (MCH)..................................................................25
2.3.1.
Front Side Bus Support..................................................................................25
2.3.2.
Integrated System Memory DRAM Controller................................................26
2.3.3.
Accelerated Graphics Port (AGP) Interface ...................................................26
2.3.4.
Packaging/Power ...........................................................................................26
2.4.
Intel 82801DBM I/O Controller Hub (ICH4-M) ...............................................................27
2.4.1.
Packaging/Power ...........................................................................................27
2.5.
Intel PRO/Wireless Network Connection.......................................................................27
2.5.1.
Packaging and Power ....................................................................................28
2.6.
Firmware Hub (FWH).....................................................................................................28
2.6.1.
Packaging/Power ...........................................................................................28
General Design Considerations .................................................................................................29
3.1.
Nominal Board Stack-Up ...............................................................................................29
FSB Design Guidelines ..............................................................................................................33
4.1.
FSB Design Recommendations.....................................................................................33
4.1.1.
Recommended Stack-up Routing and Spacing Assumptions .......................33
4.1.1.1.
Trace Space to Trace – Reference Plane Separation Ratio ..........33
4.1.1.2.
Trace Space to Trace Width Ratio..................................................34
4.1.1.3.
Recommended Stack-up Calculated Coupling Model ....................34
4.1.1.4.
Signal Propagation Time to Distance Relationship
and Assumptions.............................................................................35
4.1.2.
Common Clock Signals..................................................................................36
4.1.3.
Source Synchronous Signals.........................................................................41
4.1.3.1.
Source Synchronous General Routing Guidelines .........................41
4.1.3.2.
Source Synchronous – Data ...........................................................43
4.1.3.3.
Source Synchronous – Address .....................................................44
4.1.3.4.
Source Synchronous Signals Recommended Layout Example .....45
4.1.3.5.
Trace Length Equalization Procedures...........................................50
4.1.4.
Asynchronous Signals....................................................................................51
4.1.4.1.
Topologies.......................................................................................51
4.1.4.1.1.
Topology 1A: Open Drain (OD) Signal Driven by the
Processor – IERR# .......................................................52
4.1.4.1.2.
Topology 1B: Open Drain (OD) Signals Driven by the
Processor – FERR# and THERMTRIP#.......................53
4.1.4.1.3.
Topology 1C: Open Drain (OD) Signals Driven by the
Processor – PROCHOT#..............................................54
4.1.4.1.4.
Topology 2A: Open Drain (OD) Signal Driven by Intel
82801DBM ICH4-M – PWRGOOD ...............................55
4.1.4.1.5.
Topology 2B: CMOS Signals Driven by Intel 82801DBM
ICH4-M – DPSLP#........................................................56
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4.1.4.1.6.
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Topology 2C: CMOS Signals Driven by Intel 82801DBM
ICH4-M – LINT0/INTR, LINT1/NMI, A20M#, IGNNE#,
SLP#, SMI#, and STPCLK# ......................................... 58
4.1.4.1.7.
Topology 3: CMOS Signals Driven by Intel 82801DBM
ICH4-M to Processor and FWH – INIT#....................... 59
4.1.4.2.
Voltage Translation Logic ............................................................... 60
4.1.5.
Processor RESET# Signal ............................................................................ 60
4.1.5.1.
Processor RESET# Routing Example............................................ 62
4.1.6.
Processor and Intel 855PM MCH Host Clock Signals .................................. 63
4.1.7.
GTLREF Layout and Routing Recommendations ......................................... 65
4.1.8.
AGTL+ I/O Buffer Compensation .................................................................. 69
4.1.8.1.
Processor AGTL+ I/O Buffer Compensation .................................. 69
4.1.8.2.
Intel 855PM MCH AGTL+ I/O Buffer Compensation...................... 71
4.1.9.
Processor FSB Strapping .............................................................................. 73
4.1.10. Processor VCCSENSE/VSSSENSE Design Recommendations.............................. 75
4.2.
Intel System Validation Debug Support ........................................................................ 76
4.2.1.
In Target Probe (ITP) Support ....................................................................... 76
4.2.1.1.
Background and Justification ......................................................... 76
4.2.1.2.
Implementation ............................................................................... 76
4.2.2.
Processor Logic Analyzer Support (FSB LAI) ............................................... 76
4.2.2.1.
Background and Justification ......................................................... 76
4.2.2.2.
Implementation ............................................................................... 77
4.2.3.
Intel Pentium M Processor and Intel Celeron M Processor On-Die Logic
Analyzer Trigger Support (ODLAT) ............................................................... 77
4.3.
Onboard Debug Port Routing Guidelines ..................................................................... 77
4.3.1.
Recommended Onboard ITP700FLEX Implementation................................ 78
4.3.1.1.
ITP Signal Routing Guidelines........................................................ 78
4.3.1.2.
ITP Signal Routing Example........................................................... 82
4.3.1.3.
ITP_CLK Routing to ITP700FLEX Connector ................................ 83
4.3.1.4.
ITP700FLEX Design Guidelines for Production Systems .............. 85
4.3.2.
Recommended ITP Interposer Debug Port Implementation ......................... 86
4.3.2.1.
ITP_CLK Routing to ITP Interposer................................................ 86
4.3.2.2.
ITP Interposer Design Guidelines for Production Systems ............ 87
4.3.3.
Logic Analyzer Interface (LAI) ....................................................................... 87
4.3.3.1.
Mechanical Considerations ............................................................ 88
4.3.3.2.
Electrical Considerations ................................................................ 88
4.4.
Intel Pentium M Processor / Intel Celeron M Processor and Intel 855PM MCH FSB
Signal Package Lengths ............................................................................................... 88
Platform Power Requirements ................................................................................................... 91
5.1.
General Description....................................................................................................... 91
5.2.
Intel 855PM MCH Phase Lock Loop Power Delivery Design Guidelines ..................... 91
5.2.1.
Intel 855PM MCH PLL Power Delivery.......................................................... 91
5.2.2.
Intel 855PM MCH PLL Voltage Supply Power Sequencing .......................... 92
5.3.
Processor Phase Lock Loop Power Delivery Design Guidelines ................................. 92
5.3.1.
Processor PLL Power Delivery...................................................................... 92
5.3.2.
Processor PLL Voltage Supply Power Sequencing ...................................... 94
5.3.2.1.
Voltage Identification for Intel Pentium M/
Intel Celeron M Processor .............................................................. 94
5.3.2.2.
VCC-CORE Power Sequencing ........................................................... 97
5.4.
VCCP Output Requirements............................................................................................ 97
5.5.
VCC-MCH Output Requirements ....................................................................................... 98
5.6.
Thermal Power Dissipation ........................................................................................... 98
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5.7.
5.8.
6.
Voltage Regulator Topology ........................................................................................100
Voltage Regulator Design Recommendations ............................................................100
5.8.1.
High Current Path, Top MOSFET Turned ON .............................................101
5.8.2.
High Current Paths During Abrupt Load Current Changes .........................101
5.8.3.
High Current Paths During Switching Dead Time........................................102
5.8.4.
High Current Path with Bottom MOSFET(s) Turned ON .............................102
5.8.5.
General Layout Recommendations .............................................................103
5.9.
Processor Decoupling Recommendations ..................................................................104
5.9.1.
Transient Response .....................................................................................104
5.9.2.
High Frequency, Mid Frequency, and Bulk Decoupling...............................105
5.9.3.
Processor Core Voltage Plane and Decoupling ..........................................106
5.9.4.
Intel Pentium M Processor / Intel Celeron M Processor
and Intel 855PM MCH VCCP Voltage Plane and Decoupling........................114
5.9.4.1.
Processor VCCP Voltage Plane and Decoupling............................114
5.9.4.2.
Intel 855PM MCH VCCP Voltage Plane and Decoupling................118
5.9.5.
Intel 855PM MCH Core Voltage Plane and Decoupling ..............................119
System Memory Design Guidelines (DDR-SDRAM)................................................................125
6.1.
DDR 200/266/333 MHz System Memory Topology and Layout Design Guidelines ...126
6.1.1.
Data Signals – SDQ[71:0], SDQS[8:0].........................................................126
6.1.1.1.
Data to Strobe Length Matching Requirements............................129
6.1.1.2.
Strobe to Clock Length Matching Requirements ..........................131
6.1.1.3.
Data Routing Example ..................................................................133
6.1.1.4.
Support for Small Form Factor Design DDR Data Bus Routing ...134
6.1.2.
Control Signals – SCKE[3:0], SCS#[3:0] .....................................................134
6.1.2.1.
Control to Clock Length Matching Requirements .........................136
6.1.2.2.
Control Routing Example ..............................................................138
6.1.3.
Command Signals – SMA[12:0], SBS[1:0], SRAS#, SCAS#, SWE#...........139
6.1.3.1.
Command Topology 1 Solution.....................................................139
6.1.3.1.1.
Routing Description for Command Topology 1...........139
6.1.3.1.2.
Command Topology 1 to Clock Length Matching
Requirements..............................................................141
6.1.3.1.3.
Command Topology 1 Routing Example ....................143
6.1.3.2.
Command Topology 2 Solution.....................................................144
6.1.3.2.1.
Routing Description for Command Topology 2...........144
6.1.3.2.2.
Command Topology 2 to Clock Length Matching
Requirements..............................................................146
6.1.3.2.3.
Command Topology 2 Routing Example ....................148
6.1.4.
Clock Signals – SCK[5:0], SCK#[5:0] ..........................................................149
6.1.4.1.
Clock Signal Length Matching Requirements...............................151
6.1.4.1.1.
Clock Routing Example...............................................154
6.1.4.2.
Intel 855PM Chipset High Density Memory Support ....................155
6.1.5.
Feedback – RCVENOUT#, RCVENIN#.......................................................155
6.1.5.1.
RCVEN# Routing Example ...........................................................156
6.1.6.
Support for “DDP Stacked” SO-DIMM Modules ..........................................157
6.1.7.
Recommended Design Option to Support PC2700 DDR SDRAM
with Existing PC1600 and PC2100 Intel 855PM Platforms .........................158
6.1.7.1.
Shortened Data Signal Group Trace Length ................................158
6.1.7.1.1.
Supporting PC2700 Based on an Existing PC Platform
Layout .........................................................................158
6.1.7.1.2.
Additional Design Considerations for Adapting Intel
855PM DDR 200/266 MHz Platforms To Support
PC2700 .......................................................................159
6.2.
Intel 855PM MCH DDR Signal Package Lengths .......................................................160
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6.3.
6.4.
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DDR System Memory Interface Strapping .................................................................. 161
ECC Disable Guidelines.............................................................................................. 161
6.4.1.
Intel 855PM MCH ECC Functionality Disable ............................................. 161
6.4.2.
DDR Memory ECC Functionality Disable.................................................... 162
6.5.
System Memory Compensation .................................................................................. 162
6.6.
SMVREF Generation................................................................................................... 162
6.7.
DDR Power Delivery ................................................................................................... 162
6.8.
External Thermal Sensor Based Throttling (ETS#)..................................................... 163
6.8.1.
ETS# Usage Model...................................................................................... 163
6.8.2.
ETS# Design Guidelines ............................................................................. 164
6.8.3.
Thermal Sensor Placement Guidelines ....................................................... 164
AGP Port Design Guidelines.................................................................................................... 167
7.1.
AGP Interface .............................................................................................................. 167
7.2.
AGP 2.0 Spec.............................................................................................................. 168
7.2.1.
AGP Interface Signal Groups ...................................................................... 168
7.3.
AGP Routing Guidelines ............................................................................................. 169
7.3.1.
1x Timing Domain Routing Guidelines ........................................................ 169
7.3.1.1.
Trace Length Requirements for AGP 1X...................................... 169
7.3.1.2.
Trace Spacing Requirements....................................................... 170
7.3.1.3.
Trace Length Mismatch ................................................................ 170
7.3.2.
2X/4X Timing Domain Routing Guidelines .................................................. 170
7.3.2.1.
Trace Length Requirements for AGP 2X/4X ................................ 170
7.3.2.2.
Trace Spacing Requirements....................................................... 171
7.3.2.3.
Trace Length Mismatch Requirements ........................................ 172
7.3.3.
AGP Clock Skew ......................................................................................... 173
7.3.4.
AGP Signal Noise Decoupling Guidelines................................................... 173
7.3.5.
AGP Routing Ground Reference ................................................................. 174
7.3.6.
Pull-ups ........................................................................................................ 174
7.3.7.
AGP VDDQ and VREF ................................................................................ 176
7.3.8.
VREF Generation for AGP 2.0 (2X and 4X) ................................................ 176
7.3.8.1.
1.5-V AGP Interface (2X/4X) ........................................................ 176
7.3.9.
AGP Compensation ..................................................................................... 176
Hub Interface............................................................................................................................ 177
8.1.
Hub Interface Compensation ...................................................................................... 177
8.2.
Hub Interface Data HI[7:0] and Strobe Signals ........................................................... 177
8.2.1.
Internal Layer Routing ................................................................................. 178
8.2.2.
External Layer Routing ................................................................................ 178
8.3.
Hub Interface Data HI[10:8] Signals............................................................................ 179
8.3.1.
Internal Layer Routing ................................................................................. 179
8.3.2.
External Layer Routing ................................................................................ 179
8.3.3.
Terminating HI[11] ....................................................................................... 179
8.4.
HIREF/HI_VSWING Generation/Distribution .............................................................. 179
8.5.
Hub Interface Decoupling Guidelines.......................................................................... 181
I/O Subsystem.......................................................................................................................... 183
9.1.
IDE Interface................................................................................................................ 183
9.1.1.
Cabling......................................................................................................... 183
9.1.2.
Primary IDE Connector Requirements ........................................................ 184
9.1.3.
Secondary IDE Connector Requirements ................................................... 185
9.1.4.
Mobile IDE Swap Bay Support .................................................................... 186
9.1.4.1.
Intel 82801DBM ICH4-M IDE Interface Tri-State Feature............ 186
9.1.4.2.
S5/G3 to S0 Boot Up Procedures for IDE Swap Bay................... 187
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9.2.
9.3.
9.4.
9.5.
9.6.
9.7.
9.8.
9.9.
9.1.4.3.
Power Down Procedures for Mobile Swap Bay ............................187
9.1.4.4.
Power Up Procedures After Device “Hot” Swap Completed ........187
PCI ...............................................................................................................................188
AC’97 ...........................................................................................................................188
9.3.1.
AC’97 Routing ..............................................................................................192
9.3.2.
Motherboard Implementation .......................................................................193
9.3.2.1.
Valid Codec Configurations ..........................................................193
9.3.3.
SPKR Pin Configuration...............................................................................193
USB 2.0 Guidelines and Recommendations ...............................................................194
9.4.1.
Layout Guidelines ........................................................................................194
9.4.1.1.
General Routing and Placement...................................................194
9.4.1.2.
USB 2.0 Trace Separation ............................................................195
9.4.1.3.
USBRBIAS Connection.................................................................195
9.4.1.4.
USB 2.0 Termination.....................................................................196
9.4.1.5.
USB 2.0 Trace Length Pair Matching ...........................................196
9.4.1.6.
USB 2.0 Trace Length Guidelines ................................................196
9.4.2.
Plane Splits, Voids, and Cut-Outs (Anti-Etch)..............................................196
9.4.2.1.
VCC Plane Splits, Voids, and Cut-Outs (Anti-Etch)......................197
9.4.2.2.
GND Plane Splits, Voids, and Cut-Outs (Anti-Etch) .....................197
9.4.3.
USB Power Line Layout Topology ...............................................................197
9.4.4.
EMI Considerations......................................................................................198
9.4.4.1.
Common Mode Chokes ................................................................198
9.4.5.
ESD ..............................................................................................................199
I/O APIC (I/O Advanced Programmable Interrupt Controller) .....................................199
SMBus 2.0/SMLink Interface .......................................................................................200
9.6.1.
SMBus Architecture and Design Considerations.........................................201
9.6.1.1.
SMBus Design Considerations .....................................................201
9.6.1.2.
General Design Issues/Notes .......................................................202
9.6.1.3.
High Power/Low Power Mixed Architecture..................................202
9.6.1.4.
Calculating the Physical Segment Pull-Up Resistor .....................202
FWH .............................................................................................................................204
9.7.1.
FWH Decoupling ..........................................................................................204
9.7.2.
In Circuit FWH Programming .......................................................................204
9.7.3.
FWH INIT# Voltage Compatibility ................................................................204
9.7.4.
FWH VPP Design Guidelines ........................................................................205
9.7.5.
FWH INIT# Assertion/Deassertion Timings .................................................205
RTC..............................................................................................................................206
9.8.1.
RTC Crystal..................................................................................................207
9.8.2.
External Capacitors......................................................................................208
9.8.3.
RTC Layout Considerations .........................................................................209
9.8.4.
RTC External Battery Connections ..............................................................209
9.8.5.
RTC External RTCRST# Circuit...................................................................210
9.8.6.
VBIAS DC Voltage and Noise Measurements................................................211
9.8.7.
SUSCLK .......................................................................................................211
9.8.8.
RTC-Well Input Strap Requirements ...........................................................211
Internal LAN Layout Guidelines ...................................................................................212
9.9.1.
Footprint Compatibility .................................................................................212
9.9.2.
Intel 82801DBM ICH4-M – LAN Connect Interface Guidelines ...................213
9.9.2.1.
Bus Topologies .............................................................................213
9.9.2.1.1.
LOM (LAN On Motherboard) Point-To-Point
Interconnect ................................................................214
9.9.2.2.
Signal Routing and Layout............................................................214
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9.9.2.3.
Crosstalk Consideration ............................................................... 215
9.9.2.4.
Impedances .................................................................................. 215
9.9.2.5.
Line Termination ........................................................................... 215
9.9.2.6.
Terminating Unused LAN Connect Interface Signals................... 215
9.9.3.
Intel 82562ET / Intel 82562 EM Guidelines ................................................. 215
9.9.3.1.
Guidelines for Intel 82562ET / Intel 82562EM Component
Placement..................................................................................... 216
9.9.3.2.
Crystals and Oscillators................................................................ 216
9.9.3.3.
Intel 82562ET / Intel 82562EM Termination Resistors................. 216
9.9.3.4.
Critical Dimensions....................................................................... 217
9.9.3.4.1.
Distance from Magnetics Module to RJ-45 (Distance A)218
9.9.3.4.2.
Distance from Intel 82562ET / 82562ET to Magnetics
Module (Distance B) ................................................... 218
9.9.3.5.
Reducing Circuit Inductance ........................................................ 218
9.9.3.5.1.
Terminating Unused Connections.............................. 219
9.9.3.5.2.
Termination Plane Capacitance ................................. 219
9.9.4.
Intel 82562ET/EM Disable Guidelines......................................................... 220
9.9.5.
Design and Layout Consideration for Intel 82540EP / 82551QM ............... 221
9.9.6.
General Intel 82562ET / 82562EM / 82551QM / 82540EP Differential Pair
Trace Routing Considerations ..................................................................... 221
9.9.6.1.1.
Trace Geometry and Length ...................................... 222
9.9.6.1.2.
Signal Isolation ........................................................... 222
9.9.6.1.3.
Magnetics Module General Power and Ground Plane
Considerations............................................................ 223
9.9.6.2.
Common Physical Layout Issues ................................................. 224
9.10. Power Management Interface ..................................................................................... 225
9.10.1. SYS_RESET# Usage Model ....................................................................... 225
9.10.2. PWRBTN# Usage Model............................................................................. 225
9.10.3. Power Well Isolation Control Strap Requirements ...................................... 225
9.11. CPU I/O Signals Considerations ................................................................................. 226
Platform Clock Routing Guidelines .......................................................................................... 229
10.1. Clock Routing Guidelines ............................................................................................ 229
10.2. Clock Group Topology and Layout Routing Guidelines .............................................. 232
10.2.1. HOST_CLK Clock Group............................................................................. 232
10.2.1.1. BCLK Length Matching Requirements ......................................... 234
10.2.1.2. BCLK General Routing Guidelines............................................... 235
10.2.1.3. EMI constraints ............................................................................. 235
10.2.2. CLK66 Clock Group..................................................................................... 236
10.2.3. AGPCLK Clock Group ................................................................................. 237
10.2.4. CLK33 Clock Group..................................................................................... 238
10.2.5. PCICLK Clock Group................................................................................... 239
10.2.6. USBCLK Clock Group ................................................................................. 242
10.2.7. CLK14 Clock Group..................................................................................... 243
10.2.8. CK-408 Clock Chip Decoupling ................................................................... 243
10.3. CK-408 Updates for Systems based on Intel Pentium M Processor / Intel Celeron M
Processor and Intel 855PM Chipset ........................................................................... 244
10.4. CK-408 PWRDWN# Signal Connections .................................................................... 244
Platform Power Delivery Guidelines ........................................................................................ 245
11.1. Definitions.................................................................................................................... 245
11.2. Platform Power Requirements .................................................................................... 246
11.2.1. Platform Power Delivery Architectural Block Diagram ................................ 247
11.3. Voltage Supply ............................................................................................................ 248
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11.3.1. Power Management States..........................................................................248
Intel 855PM MCH / 82801DBM ICH4-M Platform Power-Up Sequence.....................248
11.4.1. Intel 82801DBM ICH4-M Power Sequencing Requirements.......................251
11.4.1.1. 3.3/1.5 V and 3.3/1.8 V Power Sequencing..................................251
11.4.1.2. V5REF/ 3.3 V Sequencing................................................................251
11.4.1.3. V5REF_SUS Design Guidelines .........................................................251
11.4.2. Intel 855PM MCH Power Sequencing Requirements..................................253
11.4.3. DDR Power Sequencing Requirements ......................................................253
11.5. DDR Power Delivery Design Guidelines .....................................................................254
11.5.1. DDR Interface Decoupling Guidelines .........................................................255
11.5.1.1. Intel 855PM MCH VCCSM Decoupling Guidelines ......................255
11.5.1.2. DDR SO-DIMM System Memory Decoupling Guidelines.............255
11.5.2. 2.5-V Power Delivery Guidelines .................................................................255
11.5.3. DDR Reference Voltage...............................................................................256
11.5.3.1. SMVREF Design Recommendations............................................259
11.5.3.2. DDR VREF Requirements ............................................................261
11.5.4. DDR SMRCOMP Resistive Compensation .................................................262
11.5.5. DDR VTT Termination..................................................................................262
11.5.6. DDR SMRCOMP, SMVREF, VTT 1.25-V Supply Disable in S3/Suspend ..262
11.5.6.1. VTT Rail Power Down Sequencing During Suspend ...................262
11.5.6.2. VTT Rail Power Up Sequencing During Resume .........................263
11.6. Clock Driver Power Delivery Guidelines......................................................................263
11.7. Decoupling Recommendations....................................................................................265
11.7.1. Processor Decoupling Guidelines................................................................265
11.7.2. Intel 855PM MCH Decoupling Guidelines....................................................265
11.7.3. Intel 82801DBM ICH4-M Decoupling Guidelines.........................................265
11.7.4. DDR VTT High Frequency and Bulk Decoupling.........................................267
11.7.5. AGP Decoupling...........................................................................................267
11.7.6. Hub Interface Decoupling.............................................................................267
11.7.7. FWH Decoupling ..........................................................................................267
11.7.8. General LAN Decoupling .............................................................................267
11.7.9. CK-408 Clock Driver Decoupling .................................................................268
11.8. Intel 855PM MCH Power Consumption Numbers .......................................................268
11.9. Intel 82801DBM ICH4-M Power Consumption Numbers ............................................269
11.10. Thermal Design Power ................................................................................................270
Intel® PRO/Wireless 2100 and Bluetooth Design Requirements .............................................271
12.1. PCB Interface Requirements .......................................................................................271
12.2. DC Power Requirements for Bluetooth .......................................................................271
12.3. Selective Suspend Support .........................................................................................272
12.4. Wake on Bluetooth Requirements ...............................................................................272
12.5. RF Disable Support Requirements for Intel PRO/Wireless 2100
and Bluetooth Devices.................................................................................................272
Reserved, NC, and Test Signals ..............................................................................................273
13.1. Intel Pentium M Processor and Intel Celeron M RSVD Signals ..................................273
13.2. Intel 855PM MCH RSVD Signals.................................................................................274
Platform Design Checklist ........................................................................................................275
14.1. General Information .....................................................................................................275
14.2. Customer Implementation............................................................................................276
14.3. Design Checklist Implementation ................................................................................276
14.4. Intel Pentium M Processor and Intel Celeron M Processor..........................................277
11.4.
12.
13.
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14.4.1.
14.4.2.
15.
Resistor Recommendations ........................................................................ 277
In Target Probe (ITP)................................................................................... 284
14.4.2.1. ITP700FLEX Connector 1, 2 .......................................................... 284
14.4.2.2. ITP Interposer 1, 2 .......................................................................... 287
14.4.2.3. Required Strapping when ITP Debug Port Disable 1, 2 ................. 288
14.4.3. Thermal Sensor ........................................................................................... 288
14.4.4. Decoupling Recommendations.................................................................... 288
14.5. CK-408 Clock Checklist............................................................................................... 290
14.5.1. Resistor Recommendations ........................................................................ 290
14.5.2. CK-408 Decoupling Recommendation ........................................................ 292
14.6. Intel 855PM MCH Checklist ........................................................................................ 293
14.6.1. System Memory........................................................................................... 293
14.6.1.1. MCH System Memory Interface ................................................... 293
14.6.1.2. DDR SO-DIMM Interface.............................................................. 296
14.6.2. Miscellaneous Signals ................................................................................. 298
14.6.3. Resistive Compensation.............................................................................. 300
14.6.4. Decoupling Recommendations (MCH)........................................................ 301
14.6.5. Memory Decoupling Recommendation ....................................................... 301
14.6.6. MCH Reference Voltage.............................................................................. 302
14.7. AGP Interface .............................................................................................................. 303
14.7.1. Resistor Recommendations ........................................................................ 303
14.7.1.1. AGP Connector ............................................................................ 304
14.7.1.2. AGP Decoupling Recommendations............................................ 304
14.7.1.3. AGP VREF Reference Voltage Dividers ...................................... 304
14.8. ICH4-M Checklist ........................................................................................................ 306
14.8.1. ICH4-M Resistor Recommendations........................................................... 306
14.8.2. GPIO ............................................................................................................ 308
14.8.3. AGP Busy/Stop Design Requirements ........................................................ 309
14.8.4. System Management Bus (SMBus) Interface ............................................. 310
14.8.5. AC ’97 Interface ........................................................................................... 311
14.8.6. ICH4-M Power Management Interface ........................................................ 312
14.8.7. FWH/LPC Interface...................................................................................... 314
14.8.8. USB Interface .............................................................................................. 314
14.8.9. Hub Interface ............................................................................................... 315
14.8.9.1. Hub Interface Resistor Recommendations .................................. 315
14.8.9.2. Reference Voltage Dividers.......................................................... 315
14.8.10. RTC Circuitry ............................................................................................... 317
14.8.11. LAN Interface............................................................................................... 319
14.8.12. Primary IDE Interface .................................................................................. 320
14.8.13. IDE Interface (Secondary IDE Connector) .................................................. 321
14.8.14. Miscellaneous Signals ................................................................................. 322
14.8.15. ICH4-M Power Signals & Decoupling Recommendations .......................... 323
14.9. USB Checklist ............................................................................................................. 324
14.9.1. Resistor Recommendations ........................................................................ 324
14.9.2. Decoupling Recommendations.................................................................... 325
14.10. FWH Checklist............................................................................................................. 325
14.10.1. Resistor Recommendations ........................................................................ 325
14.10.2. Decoupling Recommendations.................................................................... 325
14.11. LAN / HomePNA Checklist.......................................................................................... 326
14.11.1. LAN Interface (82562ET / 82562EM) .......................................................... 326
14.11.1.1. Resistor Recommendations ......................................................... 326
14.11.1.2. Decoupling Recommendations .................................................... 327
Intel Customer Reference Board Schematics.......................................................................... 329
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Figures
Figure 1. Basic System Block Diagram ................................................................................... 24
Figure 2. Recommended Board Stack-Up Dimensions .......................................................... 30
Figure 3. Trace Spacing vs. Trace to Reference Plane Example ........................................... 34
Figure 4. Trace Spacing vs. Trace Width Example................................................................. 34
Figure 5. Recommended Stack-up Capacitive Coupling Model ............................................. 35
Figure 6. Common Clock Signals Example – Intel 855PM MCH Escape Routing ................. 39
Figure 7. Common Clock Signals Example – Processor Escape Routing.............................. 39
Figure 8. Common Clock Signals Example – Processor to Intel 855PM MCH
Layer 6 Routing........................................................................................................ 40
Figure 9. Layer 6 FSB Source Synchronous Signals GND Referencing
to Layer 5 and Layer 7 Ground Planes.................................................................... 42
Figure 10. Layer 3 FSB Source Synchronous Signals GND Referencing
to Layer 2 and Layer 4 Ground Planes.................................................................... 42
Figure 11. Intel 855PM MCH Source Synchronous Signals Recommended Escape Routing
Example ................................................................................................................... 47
Figure 12. Processor Source Synchronous Signals Recommended Escape Routing
Example ................................................................................................................... 48
Figure 13. Processor to Intel 855PM MCH Source Synchronous Signals Routing Example . 49
Figure 14. Reference Trace Length Selection ........................................................................ 50
Figure 15. Trace Length Equalization Procedures with Allegro*............................................. 51
Figure 16. Routing Illustration for Topology 1A ....................................................................... 52
Figure 17. Routing Illustration for Topology 1B ....................................................................... 53
Figure 18. Routing Illustration for Topology 1C....................................................................... 54
Figure 19. Routing Illustration for Topology 2A ....................................................................... 55
Figure 20. Routing Illustration for Topology 2B ....................................................................... 56
Figure 21. DPSLP# Layout Routing Example ......................................................................... 57
Figure 22. Routing Illustration for Topology 2C....................................................................... 58
Figure 23. Routing Illustration for Topology 3 ......................................................................... 59
Figure 24. Voltage Translation Circuit ..................................................................................... 60
Figure 25. Processor RESET# Signal Routing Topology with NO ITP700FLEX Connector .. 61
Figure 26. Processor RESET# Signal Routing Topology With ITP700FLEX Connector........ 61
Figure 27. Processor RESET# Signal Routing Example with ITP700FLEX Debug Port........ 62
Figure 28. Processor and Intel 855PM MCH Host Clock Layout Routing Example ............... 64
Figure 29. Processor GTLREF Voltage Divider Network ........................................................ 65
Figure 30. Processor GTLREF Motherboard Layout .............................................................. 66
Figure 31. Intel 855PM MCH HVREF[4:0] Reference Voltage Generation Circuit ................. 67
Figure 32. Intel 855PM MCH HVREF[4:0] Motherboard Layout ............................................. 68
Figure 33. Processor COMP[3:0] Resistor Layout .................................................................. 70
Figure 34. Processor COMP[1:0] Resistor Alternative Primary Side Layout .......................... 70
Figure 35. Processor COMP[2] and COMP[0] 18-Mil Wide Dog Bones and Traces .............. 71
Figure 36. Intel 855PM MCH HRCOMP[1:0] Resistor Layout................................................. 72
Figure 37. Intel 855PM MCH HSWNG[1:0] Reference Voltage Generation Circuit................ 72
Figure 38. Intel 855PM MCH HSWNG[1:0] Layout ................................................................. 73
Figure 39. Processor Strapping Resistor Layout .................................................................... 74
Figure 40. VCCSENSE/VSSSENSE Routing Example....................................................................... 75
Figure 41. ITP700FLEX Debug Port Signals........................................................................... 79
Figure 42. ITP_CLK to ITP700FLEX Connector Layout Example .......................................... 84
Figure 43. ITP700FLEX Signals Layout Example ................................................................... 85
Figure 44. ITP_CLK to CPU ITP Interposer Layout Example ................................................. 87
Figure 45. Intel 855PM MCH 1.8 V VCCGA and VCCHA Recommended Power Delivery ........... 92
Figure 46. Processor 1.8 V VCCA[3:0] Recommended Power Delivery and Decoupling ...... 94
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Figure 47. Intel® Pentium® M Processor / Intel® Celeron® M Processor VID[5:0] Escape
Routing Layout Example .......................................................................................... 95
Figure 48. Power On Sequencing Timing Diagram ................................................................. 97
Figure 49. VCCP Block Diagram ................................................................................................ 98
Figure 50. VCC-MCH Block Diagram............................................................................................ 98
Figure 51. Voltage Regulator Multi-Phase Topology Example.............................................. 100
Figure 52. Buck Voltage Regulator Example......................................................................... 101
Figure 53. High Current Path With Top MOSFET Turned ON .............................................. 101
Figure 54. High Current Path During Abrupt Load Current Changes.................................... 102
Figure 55. High Current Path with Top and Bottom MOSFETs Turned Off (Dead Time) ..... 102
Figure 56. High Current Path With Bottom MOSFET(s) Turned ON ..................................... 103
Figure 57. Estimated Processor Current Consumption Change During STPCLK Exit ......... 105
Figure 58. Intel Pentium M Processor and Intel Celeron M ProcessorSocket Core Power
Delivery Corridor..................................................................................................... 107
Figure 59. Processor Core Power Delivery and Decoupling Concept................................... 108
Figure 60. VCC-CORE Power Delivery and Decoupling Example –
(Primary and Secondary Side Layers) ................................................................... 112
Figure 61. Processor Core Power Delivery “North Corridor” Zoom In View.......................... 112
Figure 62. VCC-CORE Power Delivery and Decoupling Example (Layers 3, 5, and 6) ............. 113
Figure 63. Recommended SP Cap Via Connection Layout (Secondary Side Layer) ........... 113
Figure 64. Processor VCCP Power Delivery and Decoupling Concept ................................... 116
Figure 65. Processor VCCP Power Plane and Decoupling Example ...................................... 117
Figure 66. Intel 855PM MCH VCCP Power Plane and Decoupling Concept........................... 118
Figure 67. Intel 855PM MCH VCCP Power Plane and Decoupling Recommended Layout
Example.................................................................................................................. 118
Figure 68. Intel 855PM MCH VCCP Power Delivery Recommended Layout (Zoom In View). 119
Figure 69. VCC-MCH Power Delivery and Decoupling Concept ................................................ 121
Figure 70. VCC-MCH Power Planes and Decoupling Example ................................................. 122
Figure 71. VCC-MCH Secondary Layer Decoupling Capacitor Placement (Zoom in View) ...... 123
Figure 72. Data Signal Routing Topology .............................................................................. 127
Figure 73. DQ/CB to DQS Trace Length Matching Requirements ........................................ 130
Figure 74. SDQS to SCK/SCK# Trace Length Matching Requirements ............................... 132
Figure 75. Data Signals Group Routing Example.................................................................. 133
Figure 76. Control Signal Routing Topology.......................................................................... 135
Figure 77. Control Signal to SCK/SCK# Trace Length Matching Requirements................... 137
Figure 78. Control Signals Group Routing Example.............................................................. 138
Figure 79. Command Signal Routing for Topology 1............................................................. 139
Figure 80. Command Signal to SCK/SCK# Trace Length Matching Requirements.............. 142
Figure 81. Command Signals Topology 1 Routing Example................................................. 143
Figure 82. Command Signal Routing for Topology 2............................................................. 144
Figure 83. Command Signal to SCK/SCK# Trace Length Matching Requirements.............. 147
Figure 84. Command Signals Topology 2 Routing Example................................................. 148
Figure 85. DDR Clock Routing Topology (SCK/SCK#[5:0]) .................................................. 149
Figure 86. SCK/SCK# Trace Length Matching Requirements .............................................. 152
Figure 87. Clock Pair Trace Length Matching Requirements1 ............................................... 153
Figure 88. Clock Signal Routing Example ............................................................................. 154
Figure 89. DDR Feedback (RCVEN#) Routing Topology...................................................... 155
Figure 90. RCVEN# Signal Routing Example........................................................................ 157
Figure 91. Data Signal Group (SDQ[71:0], SDQS[8:0]) Routing Topology –
PC2700, PC2100 and PC1600 Compliant ............................................................. 158
Figure 92. DDR Memory Thermal Sensor Placement ........................................................... 165
Figure 93. AGP Layout Guidelines ........................................................................................ 171
Figure 94. Hub Interface Routing Example............................................................................ 177
Figure 95. Hub Interface with Single Reference Voltage Divider Circuit ............................... 180
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Figure 96. Hub Interface with Locally Generated Reference Voltage Divider Circuit ........... 180
Figure 97. Connection Requirements for Primary IDE Connector ........................................ 184
Figure 98. Connection Requirements for Secondary IDE Connector ................................... 185
Figure 99. PCI Bus Layout Example ..................................................................................... 188
Figure 100. Intel 82801DBM ICH4-M AC’97 – Codec Connection ....................................... 189
Figure 101. Intel 82801DBM ICH4-M AC’97 – AC_BIT_CLK Topology ............................... 190
Figure 102. Intel 82801DBM ICH4-M AC’97 – AC_SDOUT/AC_SYNC Topology ............... 190
Figure 103. Intel 82801DBM ICH4-M AC’97 – AC_SDIN Topology ..................................... 191
Figure 104. Example Speaker Circuit.................................................................................... 194
Figure 105. Recommended USB Trace Spacing .................................................................. 195
Figure 106. USBRBIAS Connection...................................................................................... 196
Figure 107. Good Downstream Power Connection............................................................... 198
Figure 108. Common Mode Choke Schematic ..................................................................... 198
Figure 109. SMBUS 2.0/SMLink Protocol ............................................................................. 201
Figure 110. High Power/Low Power Mixed VCC_SUSPEND/VCC_CORE Architecture ................... 202
Figure 111. FWH VPP Isolation Circuitry .............................................................................. 205
Figure 112. RTCX1 and SUSCLK Relationship in Intel 82801DBM ICH4-M........................ 206
Figure 113. External Circuitry for Intel 82801DBM ICH4-M Where the Internal RTC
is Not Used............................................................................................................. 206
Figure 114. External Circuitry for the Intel 82801DBM ICH4-M RTC.................................... 207
Figure 115. Diode Circuit to Connect RTC External Battery ................................................. 210
Figure 116. RTCRST# External Circuit for the ICH4-M RTC ................................................ 210
Figure 117. Intel 82801DBM ICH4-M/Platform LAN Connect Section.................................. 213
Figure 118. Single Solution Interconnect .............................................................................. 214
Figure 119. LAN_CLK Routing Example............................................................................... 215
Figure 120. Intel 82562ET / Intel 82562EM Termination ...................................................... 217
Figure 121. Critical Dimensions for Component Placement ................................................. 217
Figure 122. Termination Plane .............................................................................................. 219
Figure 123. Example Intel 82562ET/EM Disable and Power Down Circuitry ....................... 220
Figure 124. Trace Routing..................................................................................................... 222
Figure 125. Ground Plane Separation................................................................................... 223
Figure 126. RTC Power Well Isolation Control ..................................................................... 226
Figure 127. Intel 82801DBM ICH4-M CPU CMOS Signals with CPU and FWH .................. 227
Figure 128. Platform Clock Topology Diagram ..................................................................... 231
Figure 129. Source Shunt Termination Topology ................................................................. 232
Figure 130. Clock Skew as Measured from Agent-to-Agent................................................. 235
Figure 131. CLK66 Group Topology ..................................................................................... 236
Figure 132. AGPCLK to AGP Connector Topology .............................................................. 237
Figure 133. AGPCLK to AGP Device Down Topology.......................................................... 237
Figure 134. CLK33 Group Topology ..................................................................................... 239
Figure 135. PCICLK Group to PCI Device Down Topology .................................................. 240
Figure 136. PCICLK Group to PCI Slot Topology ................................................................. 241
Figure 137. USBCLK Group Topology .................................................................................. 242
Figure 138. CLK14 Group Topology ..................................................................................... 243
Figure 139. Platform Power Delivery Map............................................................................. 247
Figure 140. Intel® 855PM/82801DBM Platform Power-Up Sequence................................... 249
Figure 141. Example V5REF / 3.3 V Sequencing Circuitry ...................................................... 251
Figure 142. V5REF_SUS With 5V_ALWAYS Connection Option ........................................ 252
Figure 143. V5REF_SUS With 3.3V_ALWAYS and VCC5 or
VCC5_SUS Connection Option ............................................................................. 252
Figure 144. DDR Power Delivery Block Diagram.................................................................. 254
Figure 145. Decoupling Capacitors Placement and Connectivity ......................................... 264
Figure 146. Minimized Loop Inductance Example ................................................................ 266
Figure 147. Recommended Topology for Coexistence Traces............................................. 271
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Figure 148. Processor GTLREF Voltage Divider Network .................................................... 282
Figure 149. Routing Illustration for INIT# ............................................................................... 282
Figure 150. Voltage Translation Circuit.................................................................................. 283
Figure 151. Routing Illustration for PROCHOT#.................................................................... 283
Figure 152. Clock Power Down Implementation.................................................................... 292
Figure 153. Reference Voltage Level for SMVREF[1:0] ........................................................ 295
Figure 154. Intel 855PM MCH HSWNG[1:0] Reference Voltage Generation Circuit ........... 299
Figure 155. Intel 855PM MCH HVREF[4:0] Generation Circuit............................................. 299
Figure 156. AGPREF Implementation (On Intel CRB)........................................................... 305
Figure 157. Hub Interface with Signal Reference Voltage Divider Circuit ............................. 316
Figure 158. Hub Interface with Locally Generated Reference Voltage Divider Circuit.......... 316
Figure 159 External Circuitry for the RTC.............................................................................. 318
Figure 160. USBPWR_CONN[E:A] Design Recommendation.............................................. 324
Figure 161. LAN_RST# Design Recommendation (On Intel CRB) ....................................... 327
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Tables
Table 1. FSB Common Clock Signal Internal Layer Routing Guidelines ................................ 37
Table 2. FSB Common Clock Signal External Layer Routing Guidelines.............................. 38
Table 3. FSB Data Source Synchronous Signal Trace Length Mismatch Mapping ............... 43
Table 4. FSB Source Synchronous Data Signal Routing Guidelines Topology 1................... 44
Table 5. FSB Source Synchronous Data Signal Routing Guidelines Topology 2................... 44
Table 6. FSB Address Source Synchronous Signal Trace Length Mismatch Mapping......... 45
Table 7. FSB Source Synchronous Address Signal Routing Guidelines ................................ 45
Table 8. Layout Recommendations for Topology 1A .............................................................. 52
Table 9. Layout Recommendations for Topology 1B .............................................................. 53
Table 10. Layout Recommendations for Topology 1C............................................................ 54
Table 11. Layout Recommendations for Topology 2A ............................................................ 55
Table 12. Layout Recommendations for Topology 2B ............................................................ 56
Table 13. Layout Recommendations for Topology 2C............................................................ 58
Table 14. Layout Recommendations for Topology 3 .............................................................. 59
Table 15. Processor RESET# Signal Routing Guidelines with ITP700FLEX Connector........ 62
Table 16. ITP Signal Default Strapping When ITP Debug Port Not Used .............................. 74
Table 17. Recommended ITP700FLEX Signal Terminations ................................................. 82
Table 18. Processor and MCH FSB Signal Package Trace Lengths...................................... 89
Table 19. VID vs. VCC-CORE Voltage ......................................................................................... 96
Table 20. VCC-CORE Decoupling Guidelines1 ........................................................................... 109
Table 21. VCCP Decoupling Guidelines .................................................................................. 114
Table 22. VCC-MCH Decoupling Guidelines.............................................................................. 120
Table 23. Intel 855PM Chipset DDR Signal Groups ............................................................. 125
Table 24. Data Signal Group Routing Guidelines ................................................................. 127
Table 25. SDQ[71:0] to SDQS[8:0] Length Mismatch Mapping ............................................ 129
Table 26. Control Signal to SO-DIMM Mapping .................................................................... 134
Table 27. Control Signal Routing Guidelines ........................................................................ 135
Table 28. Command Topology 1 Routing Guidelines ........................................................... 140
Table 29. Command Topology 2 Routing Guidelines ........................................................... 145
Table 30. Clock Signal Mapping1 ........................................................................................... 149
Table 31. Clock Signal Group Routing Guidelines................................................................ 150
Table 32. Feedback Signal Routing Guidelines .................................................................... 156
Table 33. Data Signal Group (SDQ[71:0], SDQS[8:0]) Routing Guidelines –
PC2700, PC2100 and PC1600 Compliant ............................................................ 158
Table 34. Existing PC2100/PC1600 DDR SDRAM Design Guidelines Required
for PC2700 Support ............................................................................................... 159
Table 35. Intel 855PM Chipset DDR Signal Package Lengths ............................................. 160
Table 36. AGP 2.0 Signal Groups ......................................................................................... 168
Table 37. AGP 2.0 Data/Strobe Associations ....................................................................... 169
Table 38. Layout Routing Guidelines for AGP 1X Signals .................................................... 170
Table 39. Layout Routing Guidelines for AGP 2X/4X Signals............................................... 172
Table 40. AGP 2.0 Data Lengths Relative to Strobe Length................................................. 172
Table 41. AGP 2.0 Routing Guideline Summary................................................................... 173
Table 42. AGP Pull-Up/Pull-Down Requirements and Straps .............................................. 175
Table 43. AGP 2.0 Pull-up Resistor Values .......................................................................... 175
Table 44. Hub Interface RCOMP Resistor Values ................................................................ 177
Table 45. Hub Interface Signals Internal Layer Routing Summary....................................... 178
Table 46. Hub Interface Signals External Layer Routing Summary...................................... 179
Table 47. Hub Interface HIREF/HI_VSWING Generation Circuit Specifications .................. 180
Table 48. AC’97 AC_BIT_CLK Routing Summary ................................................................ 190
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Table 49. AC’97 AC_SDOUT/AC_SYNC Routing Summary ................................................ 191
Table 50. AC’97 AC_SDIN Routing Summary....................................................................... 191
Table 51. Supported Codec Configurations........................................................................... 193
Table 52. USBRBIAS/USBRBIAS# Routing Summary.......................................................... 196
Table 53. USB 2.0 Trace Length Guidelines (With Common-mode Choke) ......................... 196
Table 54. Bus Capacitance Reference Chart ........................................................................ 203
Table 55. Bus Capacitance/Pull-Up Resistor Relationship.................................................... 203
Table 56. RTC Routing Summary.......................................................................................... 207
Table 57. LAN Component Connections/Features ................................................................ 212
Table 58. LAN Design Guide Section Reference .................................................................. 213
Table 59. LAN LOM Routing Summary ................................................................................. 214
Table 60. Intel 82562ET/EM Control Signals......................................................................... 220
Table 61. Intel 855PM Chipset Clock Groups........................................................................ 229
Table 62. Platform System Clock Cross-reference................................................................ 230
Table 63. BCLK/BCLK#[1:0] Routing Guidelines...................................................................233
Table 64. CLK66 Group Routing Guidelines ......................................................................... 236
Table 65. AGPCLK Routing Guidelines ................................................................................. 238
Table 66. CLK33 Group Routing Guidelines ......................................................................... 239
Table 67. PCICLK Group Routing Guidelines ....................................................................... 240
Table 68. PCICLK Group Routing Guidelines ....................................................................... 241
Table 69. USBCLK Routing Guidelines ................................................................................. 242
Table 70. CLK14 Group Routing Guidelines ......................................................................... 243
Table 71. Power Management States.................................................................................... 248
Table 72. Timing Sequence Parameters for Figure 140........................................................ 250
Table 73. DDR Power-Up Initialization Sequence ................................................................. 253
Table 74. Absolute vs. Relative Voltage Specification........................................................... 256
Table 75. DDR SDRAM Memory Supply Voltage and Current Specification ........................ 257
Table 76. MCH System Memory Supply Voltage and Current Specification......................... 258
Table 77. Termination Voltage and Current Specifications ................................................... 259
Table 78. Intel 855PM MCH System Memory I/O.................................................................. 260
Table 79. Effects of Varying Resistor Values in the Divider Circuit ....................................... 260
Table 80. DDR VREF Calculation.......................................................................................... 261
Table 81. Reference Distortion Due to Load Current ............................................................ 261
Table 82. Decoupling Requirements for the Intel 855PM MCH............................................. 265
Table 83. Decoupling Requirements for the Intel 82801DBM ICH4-M.................................. 266
Table 84. Intel 855PM MCH Power Consumption Estimates ................................................ 268
Table 85. Intel 82801DBM ICH4-M Power Consumption Estimates ..................................... 269
Table 86. Intel 855PM MCH Component Thermal Design Power ......................................... 270
Table 87. Intel 82801DBM ICH4-M Component Thermal Design Power .............................. 270
Table 88. Processor RSVD and TEST Signal Pin-Map Locations ........................................ 273
Table 89. MCH RSVD and NC Signal Pin-Map Locations .................................................... 274
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Revision History
Rev.
Order No.
Description
001
252614
Initial Release
002
252614
Updates include:
Date
March 2003
January 2004
®
®
Added Support for the Intel Celeron M processor
Incorporated information from Design Guide Update 253479-002
Updated design guidelines for supporting PC2700 (333 MHz) DDR
SDRAM
Transition from Intel 855PM DDR 266/200 MHz Chipset to Intel
855PM DDR 200/266/333 MHz Chipset Design Guidelines
System Memory SMVREF Design Update
®
Intel PRO/Wireless 2100 and Bluetooth* Design Requirements
PSB to FSB nomenclature Change
High-density Memory Support Update
003
252614
Updates include:
May 2004
®
Added Support for the Intel Pentium M processor on 90nm
process with 2-MB L2 Cache
Intel® 855PM Chipset Platform Design Guide
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Intel® 855PM Chipset Platform Design Guide
Introduction
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1.
Introduction
This design guide organizes and provides Intel’s design recommendations for systems incorporating the
Intel® 855PM chipset. These design guidelines have been developed to ensure maximum flexibility for
board designers while reducing the risk of board related issues. The Intel 855PM chipset supports the
Intel® Pentium® M Processor, Intel® Pentium® M Processor on 90nm process with 2-MB L2 Cache, and
the Intel® Celeron® M Processor. Unless specifically noted, all guidelines referencing the Intel Pentium
M processor and Intel Pentium M Processor on 90nm process with 2-MB L2 Cache are also applicable
to the Intel Celeron M processor.
1.1.
Terminology
Convention/Terminology
Definition
82801DBM ICH4-M
Refers to Intel’s next generation Intel 82801DBM Chipset I/O Controller Hub for
mobile platforms. Also referred to as ICH4-M.
855PM MCH
Refers to Intel’s next generation Intel 855PM Chipset Memory Controller Hub for
mobile platforms. Also referred to as MCH.
855PM Chipset
Refers to the platform consists of Intel 855PM Chipset Memory Controller Hub
(MCH) and Intel 82801 DBM Chipset I/O Controller Hub (ICH4-M)
Intel Pentium M Processor
Refers to the Intel Pentium M Processor and Intel Pentium M Processor on 90nm
process with 2-MB L2 Cache. Intel Pentium M Processor will reference both
processors unless specified
AC
Audio Codec
AGP
Accelerated Graphics Port
AGTL+
Assisted Gunning Transceiver Logic+
AMC
Audio/Modem Codec
Anti-Etch
Any plane-split, void or cutout in a VCC or GND plane is referred to as an anti-etch
ASF
Alert Standards Format
BER
Bit Error Rate
CMC
Common Mode Choke
CRB
Customer Reference Board
EMI
Electro Magnetic Interference
ESD
Electrostatic Discharge
FS
Full Speed – Refers to USB 1.1 Full Speed.
FSB
Front Side Bus – Processor to MCH interface
FWH
Firmware Hub – A non-volatile memory device used to store the system BIOS.
Future Pentium M Family
Processor
Refers to Intel’s future processors based on the Intel Pentium M processor microarchitecture
HS
High Speed – Refers to USB 2.0 High Speed
LPC
Low Pin Count
®
Intel® 855PM Chipset Platform Design Guide
19
Introduction
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Convention/Terminology
20
Definition
LS
Low Speed – Refers to USB 1.0 Low Speed
MC
Modem Codec
MCH
Intel’s next generation chipset memory controller hub for mobile platforms
PCM
Pulse Code Modulation
PLC
Platform LAN Connect
RTC
Real Time Clock
SMBus
System Management Bus – A two-wire interface through which various system
components can communicate
SPD
Serial Presence Detect
S/PDIF
Sony/Phillips Digital Interface
STD
Suspend-To-Disk
STR
Suspend-To-Ram
TCO
Total Cost of Ownership
TDM
Time Division Multiplexed
TDR
Time Domain Reflectometry
UBGA
Micro Ball Grid Array
UPGA
Micro Pin Grid Array
USB
Universal Serial Bus
VRM
Voltage Regulator Module
Intel® 855PM Chipset Platform Design Guide
Introduction
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1.2.
Referenced Documents
Contact your Intel Field Representatives for the latest revisions.
Document
Location
®
®
http://developer.intel.com
®
®
http://developer.intel.com
®
®
http://developer.intel.com
Intel Pentium M Processor on 90nm process with
2-MB L2 Cache Datasheet
Intel Pentium M Processor Datasheet
Intel Pentium M Processor Specification Update
®
®
Intel Celeron M Processor Datasheet
http://developer.intel.com
®
http://developer.intel.com
Intel 82801DBM I/O Controller Hub 4 Mobile
(ICH4-M) Datasheet
®
http://developer.intel.com/design/mobile/datashts/252337.htm
Intel 82801DBM I/O Controller Hub 4 Mobile
(ICH4-M) Specification Update
http://developer.intel.com/design/chipsets/specupdt
Intel 855PM Memory Controller Hub (MCH) DDR
200/266 MHz Datasheet
Intel 82802AB/82802AC Firmware Hub (FWH)
Datasheet
http://www.intel.com/design/chipsets/datashts/290658.htm
ITP700 Debug Port Design Guide
http://developer.intel.com/design/Xenon/guides/249679.htm
AGP Interface Specification
http://www.intel.com/technology/agp/agp_index.htm
Application Note AP-728: ICH Family Real Time
Clock (RTC) Accuracy and Considerations Under
Test Conditions
http://www.intel.com/design/chipsets/applnots/292276.htm
PCI Local Bus Specification
http://www.pcisig.com
JEDEC PC2100 DDR SDRAM Unbuffered SODIMM Reference Design Specification
http://www.jedec.org
JEDEC Standard, JESD79, Double Data Rate
(DDR) SDRAM Specification
http://www.jedec.org/download/search/JESD79R2.pdf
®
Intel® 855PM Chipset Platform Design Guide
21
Introduction
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Intel® 855PM Chipset Platform Design Guide
System Overview
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2.
System Overview
2.1.
Intel® CentrinoTM Mobile Technology Features
The technologies represented by the Intel Centrino brand will include an Intel Pentium M processor,
Intel 855PM chipset, and 802.11 (Wi-Fi) wireless networking capability.
The integrated Wi-Fi Certified Intel PRO/Wireless Network Connection has been designed and
validated to work with all of the Intel Centrino mobile technology components and is able to connect to
802.11 Wi-Fi certified access points. It also supports advanced wireless LAN security including Cisco*
LEAP, 802.1X, and WEP in addition to providing software-upgradeable support for future security
protocols, like WPA and full Cisco Compatible features. Finally, for comprehensive security support,
the Intel PRO/Wireless Network Connection has been verified with leading VPN suppliers like Cisco,
CheckPoint*, Microsoft* and Intel® NetStructure™.
Figure 1 illustrates the basic system block diagram.
Intel® 855PM Chipset Platform Design Guide
23
System Overview
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Figure 1. Basic System Block Diagram
Intel® Pentium® M or
®
®
Intel Celeron M
Processor
400 MHz FSB
AGP
Graphics
Controller
AGP 4X/2X
1.5V
Intel® 855PM
MCH 593 Micro
FCBGA
Hub
Interface
1.0
USB2.0/1.1 (6)
200/266/333
MHz DDR
PCI Bus
®
Intel 82801DBM
421 BGA
(ICH4-M)
IDE (2)
LAN PHY
Codecs
Mini PCI
®
Intel PRO/Wireless
Network Connection
PCI
Devices
AC97
FWH
LPC I/F
Super I/O
.
24
Intel® 855PM Chipset Platform Design Guide
System Overview
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2.2.
Intel® Pentium® M Processor/Intel® Celeron® M
Processor
2.2.1.
Architectural Features
Supports Intel Architecture with Dynamic Execution
High performance, low-power core
On-die, primary 32-kB instruction cache and 32-kB write-back data cache
On-die, second level cache with Advanced Transfer Cache Architecture
2-MB for Intel Pentium M Processor on 90nm process with 2-MB L2 Cache
1-MB for Intel Pentium M Processor
512-kB for Intel Celeron M Processor
Advanced Branch Prediction and Data Prefetch Logic
Streaming SIMD Extensions 2 (SSE2)
400-MHz, Source-Synchronous Front Side Bus
Advanced Power Management features including Enhanced Intel SpeedStep technology (not
supported by Intel Celeron M processor)
2.2.1.1.
Packaging/Power
478-pin, Micro-FCPGA and 479-ball Micro-FCBGA packages
VCC-CORE:
¾
Refer to Intel® Pentium® M Processor Datasheet, Intel® Pentium® M Processor on 90nm
process with 2-MB L2 Cache Datasheet and Intel® Celeron® M Processor Datasheet for
VCC-CORE voltages
VCCA:
¾
Intel Pentium M processor and Intel Celeron M processor: 1.8 V
¾
Intel Pentium M processor on 90nm process with 2-MB L2 Cache: 1.8 V or 1.5 V
VCCP (1.05 V)
2.3.
Intel 855PM Memory Controller Hub (MCH)
2.3.1.
Front Side Bus Support
Optimized for the Intel Pentium M processor / Intel Celeron M processor in 478-pin Micro-FCPGA
and 479-ball Micro-FCBGA packages
AGTL+ bus driver technology with integrated GTL termination resistors (gated AGTL+ receivers
for reduced power)
Intel® 855PM Chipset Platform Design Guide
25
System Overview
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Supports 32-bit AGTL+ bus addressing (no support for 36-bit address extension)
Supports Uni-processor (UP) systems
400 MT/s FSB support (100 MHz)
2X Address, 4X Data
8 deep In-Order Queue
2.3.2.
Integrated System Memory DRAM Controller
Supports up to two double-sided SO-DIMMs (four rows populated) with unbuffered
PC1600/PC2100/2700 DDR-SDRAM (with or without ECC)
Supports 64 Mb, 128 Mb, 256 Mb, and 512 Mb technologies for x8 and x16 width devices
Maximum of 2 GB of system memory by using 512-Mb stacked memory technology devices
Supports 200 MHz, 266 MHz and 33MHz DDR devices
64-bit data interface (72-bit with ECC)
PC1600/2100 system memory interface
Supports up to 16 simultaneous open pages
Support for SO-DIMM Serial Presence Detect (SPD) scheme via SMBus interface STR power
management support via self refresh mode using CKE
2.3.3.
Accelerated Graphics Port (AGP) Interface
Supports AGP 2.0 data transfers
Supports a single AGP (1X/2X/4X) device (either via a connector or on the motherboard)
Only supports 1.5-V VDDQ for AGP electricals
PCI semantic (FRAME# initiated) accesses to DRAM are snooped
AGP semantic (PIPE# and SBA) traffic to DRAM is not snooped on the FSB and is therefore not
coherent with the CPU caches
High priority access support
Delayed transaction support for AGP reads that cannot be serviced immediately
AGP Busy/Stop Protocol support
Support for D3 Hot and Cold Device states
AGP Clamping and Sense Amp control
2.3.4.
Packaging/Power
593-pin, Micro-FCBGA package (37.5 mm x 37.5 mm)
VCC-MCH (1.2 V); VCCSM (2.5 V); 1.5 V; VCCGA, VCCHA, & VCC1_8 (1.8 V); VCCP (1.05 V)
26
Intel® 855PM Chipset Platform Design Guide
System Overview
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2.4.
Intel 82801DBM I/O Controller Hub (ICH4-M)
The Intel 82801DBM provides the I/O subsystem with access to the rest of the system:
Upstream Accelerated Hub Architecture interface for access to the MCH
PCI 2.2 interface (6 PCI Request/Grant Pairs)
Bus Master IDE controller (supports Ultra ATA 100/66/33)
USB 1.1 and USB 2.0 Host Controllers and support for USB 2.0 High Speed Debug port
I/O APIC
SMBus 2.0 Controller
FWH Interface
LPC Interface
AC’97 2.2 Interface
Alert-On-LAN*
IRQ Controller
2.4.1.
Packaging/Power
421-pin, BGA package (31 mm x 31 mm)
VCC1_5 (1.5 V main logic voltage); VCCSUS1_5 (1.5 V resume logic voltage); VCCLAN1_5
(1.5 V LAN logic voltage); VCC3_3 (3.3 V main I/O voltage); VCCSUS3_3 (3.3 V resume I/O
voltage); VCCLAN3_3 (3.3 V LAN I/O voltage); V5REF (5 V); V5REF_SUS (5 V); VCCRTC;
VCCHI (1.8 V); V_CPU_IO/VCCP (1.05 V)
2.5.
Intel PRO/Wireless Network Connection
Ability to connect to 802.11 Wi-Fi Certified networks
Industry standard and extended wireless security support (WEP, 802.1X and Cisco* LEAP)
Intel® PROSet software with advanced profile management support, allows multiple setup profiles
to connect to different WLAN networks
Intel PROSet software with automatic WLAN switching support enables automatic switching
between wired & wireless LAN connections
Intel PROSet software supports Cisco, Check Point, Microsoft and Intel VPN connections†
Intel PROSet software with ad hoc connection wizard support provides a simple interface for
setting up ad hoc networks
Intel Wireless Coexistence System support enables reduced interference between Intel
PRO/Wireless & certain Bluetooth* devices
Per-packet antenna selection enables optimized WLAN performance
Intel Intelligent Scanning technology, reduces power by controlling the frequency of scanning for
access points
Intel® 855PM Chipset Platform Design Guide
27
System Overview
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Power saving capability with five different power settings allows users to trade off performance
and battery life.
2.5.1.
Packaging and Power
Mini-PCI Type 3B: (59.45 mm x 44.45 mm x 5mm)
Mini-PCI Type 3A: (59.45 mm x 50.8 mm x 5 mm)
3.3V
2.6.
Firmware Hub (FWH)
An integrated hardware Random Number Generator (RNG)
Register-based locking
Hardware-based locking
Five GPIs
2.6.1.
Packaging/Power
32-pin TSOP/PLCC
3.3-V core and 3.3 V/12 V for fast programming
28
Intel® 855PM Chipset Platform Design Guide
General Design Considerations
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3.
General Design Considerations
This section documents motherboard layout and routing guidelines for Intel 855PM chipset platforms. It
does not discuss the functional aspects of any bus, or the layout guidelines for an add-in device.
If the guidelines listed in this document are not followed, it is very important that thorough signal
integrity and timing simulations are completed for each design. Even when the guidelines are followed,
Intel recommends that critical signals be simulated to ensure proper signal integrity and flight time. Any
deviation from the guidelines should be simulated.
The trace impedance typically noted (i.e. 55 ± 15%) is the “nominal” trace impedance for a 5-mil
wide external trace and a 4-mil wide internal trace. However, some stack-ups may lead to narrower or
wider traces on internal or external layers in order to meet the 55- impedance target. Note the trace
impedance target assumes that the trace is not subjected to the EMI created by changing current in
neighboring traces. It is important to consider the minimum and maximum impedance of a trace based
on the switching of neighboring traces when calculating flight times. Using wider spaces between the
traces can minimize this trace-to-trace coupling. In addition, these wider spaces reduce settling time.
Coupling between two traces is a function of the coupled length, the distance separating the traces, the
signal edge rate, and the degree of mutual capacitance and inductance. In order to minimize the effects
of trace-to-trace coupling, the routing guidelines documented in this section should be followed. Also,
all high-speed, impedance controlled signals (e.g. FSB signals) should have continuous GND referenced
planes and cannot be routed over or under power/GND plane splits.
3.1.
Nominal Board Stack-Up
Systems incorporating the Intel 855PM chipsets requires a board stack-up yielding a target impedance of
55 ± 15%.
An example of an 8-layer board stack-up is shown in Figure 2. The left side of the figure illustrates the
starting dimensions of the metal and dielectric material thickness as well as drawn trace width
dimensions prior to lamination, conductor plating, and etching. After the motherboard materials are
laminated, conductors plated, and etched, somewhat different dimensions result. Dielectric materials
become thinner, under/over etching of conductors alters their trace width, and conductor plating makes
them thicker. It is important to note that for the purpose of extracting electrical models from
transmission line properties, the final dimensions of signals after lamination, plating, and etching should
be used.
The stack-up uses 1.2-mil (1 oz) copper on power planes to reduce I*R drops and 0.6-mil copper
thickness on the signal layers: primary side layer (L1), Layer 3 (L3), Layer 6 (L6), and secondary side
layer (L8). After plating, the external layers become 1.2 to 2 mils thick.
To meet the nominal 55- characteristic impedance primary and secondary side layer micro-strip lines
are drawn at 5-mil trace width but end up with a 5.5-mil final trace width after etching. For the same
reason, the 5-mil thick prepreg between the primary side layer and Layer 2 starts at 5 mils but becomes 4
mils after lamination. This situation and result also applies to Layer 7 and the secondary side layer.
Intel® 855PM Chipset Platform Design Guide
29
General Design Considerations
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To ensure impedance control of 55 , the primary and secondary side layer micro-strip lines should
reference solid ground planes on Layer 2 and Layer 7, respectively.
Figure 2. Recommended Board Stack-Up Dimensions
Er=4.3
L1 Signals
L2 GND Plane
L3 Signals
Final Dimensions after
Lamination, Etching, Plating
1.5mil
After
plating
5.0mil
Prepreg 4.0mil
Core 4.0mil
4.0mil
0.6mil
Prepreg 11.0mil
L4 GND/PWR
Plane
L7 GND Plane
L8 Signals/
Power
1.2mil
Core 12.0mil
L5 GND/PWR
Plane
L6 Signals
1.2mil
0.6mil
1.2mil
Prepreg 11.0mil
4.0mil
Core 4mil
1.2mil
Prepreg 4.0mil
1.0mil
Solder Mask
1.5mil
After plating
Internal signal traces on Layer 3 and Layer 6 are unbalanced strip-lines. To meet the nominal 55characteristic impedance for these traces, they reference a solid ground plane on Layer 2 and Layer 7.
Since the coupling to Layer 4 and Layer 5 is still significant, (especially true when thinner stack-ups use
balanced strip-lines on internal layers) these layers are converted to ground floods in the areas of the
motherboard where the high-speed interfaces like the FSB or DDR system memory are routed. In the
remaining sections of the motherboard layout the Layer 4 and Layer 5 layers are used for power
delivery.
For 55- characteristic impedance Layer 3 (Layer 6), strip-lines have a 4-mil final trace width and are
separated by a core dielectric thickness of 4 mils after lamination from the Layer 2 (Layer 7) ground
plane and 11-mil thickness prepreg after lamination to separate it from Layer 4 (Layer 5). The starting
thickness of these core and prepreg dielectric layers before lamination is 5 mils and 12 mils,
respectively.
The secondary side layer is also used for power delivery in many cases since it benefits from the thick
copper plating of the external layer plating as well as referencing the close (4-mil prepreg thickness)
Layer 7 ground plane. The benefit of such a stack-up is low inductance power delivery.
OEMs may choose to use different stack-ups (number of layers, thickness, trace width, etc.) from the
one example outlined in Figure 2. However, the following key elements should be observed:
1. Final post lamination, post etching, and post plating dimensions should be used for electrical
model extractions.
2. Power plane layers should be 1 oz thick and signal layers should be ½ oz thick.
3. External layers become 1 – 1.5 oz (1.2 – 2 mils) thick after plating
30
Intel® 855PM Chipset Platform Design Guide
General Design Considerations
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4.
5.
6.
7.
All high-speed signals should reference solid ground planes through the length of their routing
and should not cross plane splits. To guarantee this, both planes surrounding strip-lines should be
GND.
Intel recommends that high-speed signal routing be done on internal, strip-line layers.
High-speed signals transitioning between layers next to the component, signal pins should be
accounted for by the GND stitching vias that would stitch all the GND plane layers in that area of
the motherboard. Due to the arrangement of the Intel® Pentium® M Processor / Intel® Celeron®
M Processor and Intel 855PM MCH pin-maps, GND vias placed near all GND lands will also be
very close to high-speed signals that may be transitioning to an internal layer. Thus, no additional
ground stitching vias (besides the GND pin vias) are required in the immediate vicinity of the
processor and MCH packages to accompany the signal transitions from the component side into
an internal layer.
High-speed routing on external layers should be minimized in order to avoid EMI. Routing on
external layers also introduces different delays compared to internal layers, making it extremely
difficult to do length matching if some routing is done on both internal and external layers.
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Intel® 855PM Chipset Platform Design Guide
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4.
FSB Design Guidelines
The following layout guidelines support designs using the Intel Pentium M processor / Intel Celeron M
processor and the Intel 855PM MCH chipset. Due to on-die Rtt resistors on both the processor and the
chipset, additional resistors do not need to be placed on the motherboard for most FSB signals. A simple
point-to-point interconnect topology is used in these cases.
4.1.
FSB Design Recommendations
For proper operation of the processor and the chipset, the system designer must meet the timing and
voltage specification of each component. The following recommendations are Intel’s best guidelines
based on extensive simulation and experimentation that make assumptions, which may be different than
an OEM’s system design. The most accurate way to understand the signal integrity and timing of the
FSB in your platform is by performing a comprehensive simulation analysis. It is possible that
adjustments to trace impedance, line length, termination impedance, board stack-up, and other
parameters can be made that improve system performance.
Refer to the latest Intel® Pentium® M Processor Datasheet, Intel® Pentium® M Processor on 90nm
process with 2-MB L2 Cache Datasheet or Intel® Celeron® M Processor Datasheet for a FSB signal list,
signal types, and definitions. Below are the design recommendations for the data, address, and strobes.
For the following discussion, the pad is defined as the attach point of the silicon die to the package
substrate. The guidelines are derived from empirical testing with Intel 855PM chipset MCH package
models.
4.1.1.
Recommended Stack-up Routing and Spacing Assumptions
The following section describes in more detail, the terminology and definitions used for different routing
and stack-up assumptions that apply to the recommended motherboard stack-up show in Figure 2.
4.1.1.1.
Trace Space to Trace – Reference Plane Separation Ratio
Figure 3 illustrates the recommended relationship between the edge-to-edge trace spacing (2X) versus
the trace to reference plane separation (X). An edge-to-edge trace spacing (2X) to trace – reference
plane separation (X) ratio of 2 to 1 ensures a low crosstalk coefficient. All the effects of crosstalk are
difficult to simulate. The timing and layout guidelines for the Intel Pentium M/Intel Celeron M
processor have been created with the assumption of a 2:1 trace spacing to trace – reference plane ratio.
A smaller ratio would have an unpredictable impact due to crosstalk.
Intel® 855PM Chipset Platform Design Guide
33
FSB Design Guidelines
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Figure 3. Trace Spacing vs. Trace to Reference Plane Example
Reference Plane (VSS)
X
2X
Trace
4.1.1.2.
Trace
Trace Space to Trace Width Ratio
Figure 4 illustrates the recommended relationship between the edge-to-edge trace spacing versus trace
width ratio for the best signal quality results. In general, a 3:1 trace space to trace width ratio is preferred
and highly recommended. In case of routing difficulties on the motherboard, using a 2:1 ratio would be
acceptable only if additional simulations conclude that it is possible, and this may include some changes
to the stack-up or routing assumptions. In the case of the FSB signals, routing recommendations for a
2:1 trace spacing to trace width ratio can be found in Topology 2 for the source synchronous signals (see
Table 5).
Figure 4. Trace Spacing vs. Trace Width Example
Trace
v
Trace
3X
X
v
4.1.1.3.
Recommended Stack-up Calculated Coupling Model
The importance of maintaining an adequate trace space to trace width ratio is to achieve the best signal
quality possible given routing constraints. The simulations performed that resulted in the recommended
3:1 trace space to trace width ratio is to keep the coupling between adjacent traces below a maximum
value. For the recommended stack-up, the constants shown in Figure 5 are assumed to be constant for a
typical stack-up. This means the mutual to self-coupling relationship given below does not take into
account the normal tolerances that are allowed for in the recommended board stack-up’s parameters. For
the recommended stack-up shown in Figure 2, the calculated capacitive coupling maximum value is
represented by the following relationship:
( CMUTUAL / CSELF ) x 100 = 8.15%
As shown in Figure 5, the coupling values are calculated based on a three-line model, represented by
Trace 1, Trace 2, and Trace 3. Based on the capacitive coupling model shown, the aforementioned
parameters are:
CMUTUAL = C21 + C23
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Intel® 855PM Chipset Platform Design Guide
FSB Design Guidelines
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CSELF = C22 (Trace 2, i.e. CS2a + CS2b)
If a stack-up that is employed does not adhere to the recommended stack-up, then a new extraction must
be made for the stack-up using a 2D field solver program. According to the 2D field solver results, new
coupling calculations must be performed to ensure that the coupling results are less than the
aforementioned capacitive coupling maximum value of 8.15%. If the coupling results are greater than
the maximum value, then additional system level simulations must be performed to avoid any signal
quality issues due to crosstalk effects.
Figure 5. Recommended Stack-up Capacitive Coupling Model
Note : CS1a + CS1b = C11
CS2a + CS2b = C22
CS3a +CS3b = C33
GND
CS1a
CS3a
CS2a
11.2 Mil
Trace 1
Trace 2
C21
CS1b
Trace 3
C23
CS2b
CS3b
4.8 Mil
GND
4.1.1.4.
Signal Propagation Time to Distance Relationship and Assumptions
Due to the high frequency nature of some interfaces and signals, length matching may or may not exist
as part of the routing requirements for a given interface. In general, the tolerances that specific signals in
a bus must be routed to will be stated as a length measured in mils or inches and is specific to the
recommended motherboard stack-up (see Figure 2). However, some length matching tolerances for
signals listed in this design guide may be stated as a measurement of time. In such cases, the correlation
of the period of time to an actual length value will depend on board stack-up.
Based on the recommended stack-up, the signal propagation time to distance relationship, for the
purpose of this design guide, is as follows:
Strip-line (internal layer) Routing: 180 ps for 1.0 inch
Micro-strip (external layer) Routing: 162 ps for 1.0 inch
For example, a length-matching requirement of ± 50 ps for routing on a strip-line (internal) layer would
correlate to a trace length whose tolerance is within ± 278 mils of an associated trace. The signal
propagation time to distance relationship listed above is based on a single transmission line model
incorporating a typical stack-up. Thus, no other signals or traces are accounted for in such a model and
there is an assumption of zero coupling with other traces. Also, the recommended stack-up’s parameter
tolerances are not taken into account in the “typical” stack-up assumptions. Finally, in cases that need to
account for worst-case stack-up parameters and for even or odd mode coupling, new extractions from
the stack-up model must be done to provide an accurate signal propagation time to distance relationship.
Intel® 855PM Chipset Platform Design Guide
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4.1.2.
Common Clock Signals
All common clock signals use an AGTL+ bus driver technology with on die integrated GTL termination
resistors connected in a point-to-point, Zo = 55 , controlled impedance topology between the processor
and the Intel 855PM chipset MCH. No external termination is needed on these signals. These signals
operate at the FSB frequency of 100 MHz.
Common clock signals should be routed on an internal or external layer while referencing solid ground
planes. Common clock signal routing on internal layers implemented with complete reference to ground
planes both above and below the signal layer is recommended. Based on current simulation results,
routing on internal layers allows for a minimum pin-to-pin motherboard length of 1.0 inch and a
maximum of 6.5 inches. Routing on external layers allows for a pin-to-pin motherboard length of 1.0
inch and a maximum of 6.5 inches. Trace length matching for the common clock signals is not required.
Intel recommends routing these signals on the same internal or external layer for the entire length of the
bus. If routing constraints require routing of these signals with a transition to a different layer, a
minimum of one ground stitching via for every two signals should be placed within 100 mils of the
signal transition vias.
Routing of the common clock signals should use a minimum of 1:2 trace spacing. This implies a 4-mil
trace width with a minimum of 8-mil spacing (i.e. 12-mil minimum pitch) for routing on internal layers.
For external layers, route using a 5-mil trace width and a 10-mil minimum spacing (i.e. 15-mil pitch).
Practical cases of escape routing under the MCH or the processor package outline and near by vicinity
may not allow the implementation of 1:2 trace spacing requirements. Although every attempt should be
made to maximize the signal spacing in these areas, it is allowable to have 1:1 trace spacing underneath
the MCH and the processor package outlines and up to 200 – 300 mils outside the package outline.
Table 1 summarizes the list of common clock and key routing requirements. RESET# (CPURST# of
MCH) is also a common clock signal but requires a special treatment for the case where an
ITP700FLEX debug port is used. See Section 4.1.5 for further details. Figure 6 and Figure 7 illustrate
an example of escape routing from the processor and the Intel 855PM chipset MCH package vicinity for
the common clock signals. To allow for flat routing, DEFER#, DRDY#, HIT#, HITM#, TRDY#, and
BNR# would have to have minimal routing on the primary side in the vicinity of the MCH package and
then the rest of the routing continues on internal layer 6. The ground vias of the MCH pins provide the
needed ground stitching vias for a layer transition for these signals. The remaining signals have standard
dog bone (a land for a BGA ball followed by a short trace to a via with a 25-mil offset in the X and Y
directions) vias on the primary side and continue to the processor in a simple point-to-point connection.
The processor only has straightforward dog bones on the primary side for this group of signals. Figure 8
shows a global routing summary of these common clock signals as a simple point-to-point connection
on Layer 6 between the processor and the Intel 855PM MCH.
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Intel® 855PM Chipset Platform Design Guide
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Table 1. FSB Common Clock Signal Internal Layer Routing Guidelines
Signal Names
Total Trace Length
Transmission Line
Type
Nominal
Impedance
( )
Width &
spacing
(mils)
Min
(inches)
Max
(inches)
Strip-line
1.0
6.5
55 ± 15%
4&8
BNR#
Strip-line
1.0
6.5
55 ± 15%
4&8
BPRI#
BPRI#
Strip-line
1.0
6.5
55 ± 15%
4&8
BR0#
BREQ0#
Strip-line
1.0
6.5
55 ± 15%
4&8
DBSY#
DBSY#
Strip-line
1.0
6.5
55 ± 15%
4&8
DEFER#
DEFER#
Strip-line
1.0
6.5
55 ± 15%
4&8
DPWR#
DPWR#
Strip-line
1.0
6.5
55 ± 15%
4&8
DRDY#
DRDY#
Strip-line
1.0
6.5
55 ± 15%
4&8
HIT#
HIT#
Strip-line
1.0
6.5
55 ± 15%
4&8
HITM#
HITM#
Strip-line
1.0
6.5
55 ± 15%
4&8
LOCK#
HLOCK#
Strip-line
1.0
6.5
55 ± 15%
4&8
RS[2:0]#
RS[2:0]#
Strip-line
1.0
6.5
55 ± 15%
4&8
TRDY#
HTRDY#
Strip-line
1.0
6.5
55 ± 15%
4&8
CPURST#
Strip-line
1.0
6.5
55 ± 15%
4&8
CPU
MCH
ADS#
ADS#
BNR#
RESET#
NOTE:
1
For topologies where an ITP700FLEX debug port is implemented, see Section 4.1.5 for RESET#
(CPURST#) implementation details.
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Table 2. FSB Common Clock Signal External Layer Routing Guidelines
Signal Names
Total Trace Length
Transmission Line
Type
Width &
spacing
(mils)
Min
(inches)
Max
(inches)
Micro-strip
1.0
6.5
55 ±15%
5 & 10
BNR#
Micro-strip
1.0
6.5
55 ±15%
5 & 10
BPRI#
BPRI#
Micro-strip
1.0
6.5
55 ± 15%
5 & 10
BR0#
BREQ0#
Micro-strip
1.0
6.5
55 ± 15%
5 & 10
DBSY#
DBSY#
Micro-strip
1.0
6.5
55 ± 15%
5 & 10
DEFER#
DEFER#
Micro-strip
1.0
6.5
55 ± 15%
5 & 10
DPWR#
DPWR#
Micro-strip
1.0
6.5
55 ± 15%
5 & 10
DRDY#
DRDY#
Micro-strip
1.0
6.5
55 ±15%
5 & 10
HIT#
HIT#
Micro-strip
1.0
6.5
55 ±15%
5 & 10
HITM#
HITM#
Micro-strip
1.0
6.5
55 ±15%
5 & 10
LOCK#
HLOCK#
Micro-strip
1.0
6.5
55 ± 15%
5 & 10
RS[2:0]#
RS[2:0]#
Micro-strip
1.0
6.5
55 ± 15%
5 & 10
TRDY#
HTRDY#
Micro-strip
1.0
6.5
55 ± 15%
5 & 10
CPURST#
Micro-strip
1.0
6.5
55 ± 15%
5 & 10
CPU
MCH
ADS#
ADS#
BNR#
RESET#
NOTE:
38
Nominal
Impedance
( )
1
For topologies where an ITP700FLEX debug port is implemented, see Section 4.1.5 for RESET#
(CPURST#) implementation details.
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Figure 6. Common Clock Signals Example – Intel 855PM MCH Escape Routing
PRIMARY SIDE
HIT#
DEFER#
HITM#
Layer 6
COMMON
Clock
Signals
DRDY#
TRDY#
BNR#
DPSLP#
RESET#
Figure 7. Common Clock Signals Example – Processor Escape Routing
Layer 6
DPSLP#
RESET#
COMMON
Clock
Signals
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Figure 8. Common Clock Signals Example – Processor to Intel 855PM MCH Layer 6 Routing
Mother Board Layer 6 routing
Intel Intel®
Pentium M
PentiumMM
processor
Pentium®
Intel
Intel®
855PM
855PM
855PM
MCH-M
MCH
MCH-M
40
COMMON
Clock Signals
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4.1.3.
Source Synchronous Signals
All source synchronous signals use an AGTL+ bus driver technology with on-die GTL termination
resistors connected in a point-to-point, Zo = 55 controlled impedance topology between the Intel
Pentium M/Intel Celeron M processor and the Intel 855PM MCH. No external termination is needed on
these signals. Source synchronous FSB address signals operate at a double pumped rate of 200 MHz
while the source synchronous FSB data signals operate at a quad pumped rate of 400 MHz. High-speed
operation of the source synchronous signals requires careful attention to their routing considerations.
The following guidelines should be strictly adhered to, to guarantee robust high-frequency operation of
these signals.
4.1.3.1.
Source Synchronous General Routing Guidelines
Source synchronous data and address signals and their associated strobes are partitioned into groups of
signals. Flight time skew minimization within the same group of source synchronous signals is a key
parameter that allows their high frequency (400 MHz) operation. All the source synchronous signals that
belong to the same group should be routed on the same internal layer for the entire length of the bus.
It is acceptable to split different groups of source synchronous signals between different motherboard
layers as long as all the signals that belong to that group are kept on the same layer. Grouping of FSB
source synchronous signals is summarized in Table 3 and Table 6. This practice results in a significant
reduction of the flight time skew since the dielectric thickness, line width, and velocity of the signals
will be uniform across a single layer of the stack-up. There is no guarantee of a relationship of dielectric
thickness, line width, and velocity between layers.
The source synchronous signals should be routed as a strip-line on an internal layer with complete
reference to ground planes both above and below the signal layer. Routing with references to split
planes or power planes other than ground is not allowed. For the recommended stack-up example as
shown in Figure 2, source synchronous FSB signals are routed on Layer 3 and Layer 6. Layer 2 and
Layer 7 are solid grounds across the entire motherboard. However, this is not sufficient since significant
coupling exists between signal Layer 3 and power plane Layer 2 as well as signal Layer 6 and power
plane Layer 5. To guarantee complete ground referencing, Layer 4 and Layer 5 are converted to ground
plane floods in the areas where the source synchronous FSB signals are routed. In addition all the
ground plane areas are stitched with ground vias in the vicinity of the processor and Intel 855PM MCH
package outlines with the vias of the ground pins of the processor and MCH pin-map.
Figure 9 illustrates a motherboard layout and a cross-sectional view of the recommended stack-up of the
FSB source synchronous DATA and ADDRESS signals referencing ground planes on both Layer 7 and
Layer 5. Notice that in the socket cavity of the processor Layer 5 and Layer 6 layers is used for VCC
core power delivery. However, outside the socket cavity Layer 6 signals are routed on top of a solid
Layer 7 ground plane and also Layer 5 is converted to a ground flood under the shadow of the FSB
signals routing between the processor and MCH. Stitching of all the GND planes is provided by the
ground vias in the pin-map of the processor and MCH.
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Figure 9. Layer 6 FSB Source Synchronous Signals GND Referencing to Layer 5 and Layer 7
Ground Planes
L6 and L5 top side view
VCC
Stackup cross-section
L4
L5
L6
L7
GND
GND
BSB DATA
BSB ADDRESS
VCC
In a similar way, Figure 10 illustrates a recommended layout and stack-up example of how another
group of FSB source synchronous DATA and ADDRESS signals can reference ground planes on both
Layer 2 and Layer 4. Note that in the socket cavity of the processor, Layer 3 is used for VCC core
power delivery to reduce the I*R drop. However, outside of the socket cavity Layer 3 signals are routed
below a solid Layer 2 ground plane and also Layer 4 is converted to a ground flood under the shadow of
the FSB signals routing between the processor and MCH.
Figure 10. Layer 3 FSB Source Synchronous Signals GND Referencing to Layer 2 and Layer 4
Ground Planes
L3 and L4 top side view
VCC
Stackup cross-section
L2
L3
L4
GND
GND
BSB DATA
BSB ADDRESS
100MHz CLKs
42
VCC
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Skew minimization requires pin-to-pin trace length matching of the FSB source synchronous signals that
belong to the same group including the strobe signals of that group. Trace length matching of the
processor and MCH packages does not need to be accounted for in the motherboard routing since both
packages have the source synchronous signals and the strobes length matched within the group inside
the package routing.
Current simulation results provide routing guidelines using 1:3 spacing (Topology 1) for the FSB source
synchronous signals. This implies 4-mil trace width with a minimum of 12-mil spacing (i.e. 16-mil
minimum pitch). Practical cases of escape routing under the MCH or processor package outline and near
by vicinity may not even allow the implementation of 1:2 trace spacing requirements. Although every
attempt should be made to maximize the signal spacing in these areas, it is allowable to have 1:1 trace
spacing underneath the MCH and the processor package outlines and up to 200 – 300 mils outside the
package outline.
Routing guidelines using 1:2 spacing is available and can be used wherever 1:3 spacing cannot be
implemented by using Topology 2. The benefits of additional spacing include increased signal quality
and voltage margining. The trace routing and length matching requirements are provided in the
following sections.
4.1.3.2.
Source Synchronous – Data
Robust operation of the 400-MHz, source synchronous data signals require tight skew control. For this
reason, these signals are split into matched groups as outlined in Table 3. All the signals within the same
group should be kept on the same layer of motherboard routing and should be routed to the same pad-topad length within ± 100 mils of the associated strobes. Because the processor and Intel 855PM MCH
packages provide package trace equalization for signals within each data group, all signals should be
routed on the system board to meet the pin-to-pin matching requirement of ± 100 mils. The two
complementary strobe signals associated with each group should be length matched to each other within
± 25 mils and tuned to the average length of the data signals of their associated group. This will
optimize setup/hold time margin.
Table 3. FSB Data Source Synchronous Signal Trace Length Mismatch Mapping
CPU Signal Name
Signal Matching
Strobes associated With the
Group
Strobe Matching
Notes
D[15:0]#, DINV0#
± 100 mils
DSTBP0#, DSTBN0#
± 25 mils
1
D[31:16]#, DINV1#
± 100 mils
DSTBP1#, DSTBN1#
± 25 mils
1
D[47:32]#, DINV2#
± 100 mils
DSTBP2#, DSTBN2#
± 25 mils
1
D[63:48]#, DINV3#
± 100 mils
DSTBP3#, DSTBN3#
± 25 mils
1
NOTE:
Strobes of the same group should be trace length matched to each other within ±25 mil and to the average
length of their associated Data signal group.
Table 4 lists the source synchronous data signal general routing requirements. Due to the 400-MHz,
high-frequency operation of the data signals, 1:3 spacing is strongly advised and should be limited to a
pin-to-pin trace length minimum of 0.5 inches and maximum of 5.5 inches.
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Table 4. FSB Source Synchronous Data Signal Routing Guidelines Topology 1
Signal Names
Total Trace Length
Transmission
Line Type
Min
(inches)
Max
(inches)
Nominal
Impedance
( )
Width &
spacing (mils)
CPU
MCH
DINV[3:0]#
DBI[3:0]#
Strip-line
0.5
5.5
55 ± 15%
4 & 12
D[63:0]#
HD[63:0]#
Strip-line
0.5
5.5
55 ±15%
4 & 12
DSTBN[3:0]#
HDSTBN[3:0]#
Strip-line
0.5
5.5
55 ± 15%
4 & 12
DSTBP[3:0]#
HDSTBP[3:0]#
Strip-line
0.5
5.5
55 ±15%
4 & 12
If routing space constraints do not allow 1:3 spacing of the source synchronous data signals, Table 5
lists alternative routing requirements for some of these signals if 1:2 spacing is used. In both topologies,
the pin-to-pin trace length should be limited to a minimum of 0.5 inches and a maximum of 5.5 inches.
The adherence to tighter characteristic trace impedance tolerances for the alternative routing
requirements allows the closer spacing of the data and bus inversion signals to be achieved. The use of ±
10% tolerance for the trace impedance in the alternative topology allows designs to maintain the same
overall minimum and maximum trace lengths as the primary topology that utilizes a looser ± 15%
tolerance. Although the data and bus inversion signals for the FSB can be routed with 1:2 spacing when
using the tighter trace impedance tolerance, the data strobes must maintain 1:3 spacing. In this case, the
processor’s DSTBN[3:0]# and DSTBP[3:0]# strobe signals must be routed to the MCH’s
HDSTBN[3:0]# and HDSTBP[3:0]# strobe signals with 1:3 spacing from all signals even if ± 10% trace
impedance tolerance is used.
Table 5. FSB Source Synchronous Data Signal Routing Guidelines Topology 2
Signal Names
Total Trace Length
Transmission
Line Type
4.1.3.3.
Nominal
Impedance
( )
Width & spacing
(mils)
Min
(inches)
Max
(inches)
Strip-line
0.5
5.5
55 ± 10%
4&8
HD[63:0]#
Strip-line
0.5
5.5
55 ± 10%
4&8
DSTBN[3:0]#
HDSTBN[3:0]#
Strip-line
0.5
5.5
55 ±10%
4 & 12
DSTBP[3:0]#
HDSTBP[3:0]#
Strip-line
0.5
5.5
55 ± 10%
4 & 12
CPU
MCH
DINV[3:0]#
DBI[3:0]#
D[63:0]#
Source Synchronous – Address
Source synchronous address signals operate at 200 MHz. Thus, their routing requirements are very
similar to the data signals. Refer to Sections 4.1.3.1 and 4.1.3.2 for further details. Table 6 details the
partition of the address signals into matched length groups. Due to the lower operating frequency of the
address signals, pin-to-pin length matching is relaxed to ± 200 mils. Each group is associated with only
one strobe signal. To maximize setup/hold time margin, the address strobes should be trace length
matched to the average trace length of the address signals of their associated group. In addition, each
address signal should be trace length matched within ± 200 mils of its associated strobe signal.
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Table 6. FSB Address Source Synchronous Signal Trace Length Mismatch Mapping
Signal Matching Strobe Associated With the Group Strobe to Assoc. Address Notes
Signal Matching
CPU Signal Name
REQ[4:0]#, A[16:3]#
± 200 mils
ADSTB0#
± 200 mils
1, 2
A[31:17]#
± 200 mils
ADSTB1#
± 200 mils
1, 2
NOTES:
1. ADSTB[1:0]# should be trace length matched to the average length of their associated Address signals group.
2. Each Address signal should be trace length matched to its associated Address Strobe within ± 200 mils.
Table 7 lists the source synchronous address signals general routing requirements. Due to the 200-MHz,
high frequency operation of the address signals, 1:3 spacing is strongly advised and trace lengths should
be limited to a pin-to-pin trace length minimum of 0.5 inches and a maximum of 6.5 inches. The routing
guidelines listed in Table 7 allows for 1:2 spacing for the address signals given a 55 ± 15%
characteristic trace impedance. But if space permits, 1:3 spacing should be applied to these signals. For
the address strobes, 1:3 spacing is required irrespective of the tolerance of the trace impedance. This is a
change from previous recommendations where 1:2 spacing was acceptable for ± 15% impedance
tolerances.
Table 7. FSB Source Synchronous Address Signal Routing Guidelines
Signal Names
Total Trace Length
Transmission
Line Type
4.1.3.4.
Nominal
Impedance
( )
Width & Spacing
(mils)
Min
(inches)
Max
(inches)
Strip-line
0.5
6.5
55 ± 15%
4&8
HREQ[4:0]#
Strip-line
0.5
6.5
55 ± 15%
4&8
HADSTB[1:0]#
Strip-line
0.5
6.5
55 ± 15%
4 & 12
CPU
MCH
A[31:3]#
HA[31:3]#
REQ[4:0]#
ADSTB#[1:0]
Source Synchronous Signals Recommended Layout Example
Figure 11 illustrates escape routing of the FSB source synchronous signals in the vicinity of the Intel
855PM MCH package. The primary side has minimum length dog bones from the BGA lands that
transition with vias into internal routing Layer 3 and Layer 6. Note the change in orientation of the dog
bone “dipoles” as it changes from place to place to allow smooth escape routing on Layer 3 and Layer 6
later on in between the GND vias. The signals are split about half and half between Layer 3 and Layer 6.
For address signals, the first group containing REQ[4:0]#, A[16:3]#, and ADSTB[0]# are routed on
Layer 3. The second group of address signals containing A[31:17]# and ADSTB[1]# is routed on Layer
6. Similarly, D[15:0]#, DINV[0]#, DSTBN[0]#, DSTBP[0]# and D[47:32]#, DINV[2]#, DSTBN[2]#,
DSTBP[2]# are routed on Layer 3. The remaining two data signals groups with associated strobe and
DINV signals are routed on Layer 6. A vertical corridor with no routing on Layer 6 to the left of the
D[63:48]# group is used to feed the 1.2-V core power plane of the MCH.
Figure 11 also illustrates how a horizontal corridor with no routing on Layer 3 in between the address
and data signals allows feeding of the VCCA (1.8 V) power plane to the PLL power delivery pins
VCCGA and VCCHA of the Intel 855PM MCH and continues to the VCCA[3:0] pins of the processor.
Notice that this 1.8-V VCCA power plane “forks” as a separate branch from the 1.8-V decoupling
capacitor while the Hub Interface (HI) 1.8-V power pins connect to a separate branch of the 1.8-V
power plane flood on Layer 3. This is done to reduce noise pickup of the PLL power delivery due to HI
switching activity.
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Figure 12 illustrates the processor socket vicinity escape routing of the source synchronous FSB signals
and their successful coexistence with robust power delivery. All source synchronous signals are
connected with minimum length dog bones from the BGA lands of the socket on the primary side layer
into internal layers Layer 3 and Layer 6. In Figure 11, note the changing orientation of the dog bone
“dipoles” as they rotate around the sides of the pin field to guarantee smooth escape routing on Layer 3
and Layer 6.
In addition to signal routing on the primary side, Layer 3 and Layer 6 are also used to feed the core
power delivery into the areas free of signals routing. VCCA (1.8 V) starts from the MCH in Figure 11
and is routed on Layer 3 and is connected with a cluster of vias to a VCCA flood on the primary side
layer. This feeds the primary side “U shape” on the three sides of the processor socket that feeds the
VCCA[3:0] pins. To minimize loop inductance of the VCCA (1.8 V) vias, they are accompanied by two
GND stitching vias.
Figure 13 shows a global view of FSB source synchronous signal routing and its coexistence with a
robust power delivery layout solution. Source synchronous signals are serpentine length matched on
Layer 3 and Layer 6 in the area in between the processor and Intel 855PM MCH packages per the
procedure described in Section 4.1.3.5. Also, the source synchronous address signals route around the
thermal backing plate hole and utilize the space on Layer 3 and Layer 6 in the socket vicinity to perform
trace length equalization.
Since GTLREF generation and the COMP[3:0] resistor connections minimize via use, there is minimal
interaction between these vias with the routing of the source synchronous signals. Refer to Section 4.1.7,
Figure 29, Figure 31, and Section 4.1.8.1 for further details.
Also the complete corridor flood routing of VCCA from the MCH can be seen on Figure 13 starting on
Layer 3 and then transitioning to the primary side of the motherboard with the cluster of vias next to the
processor socket. Figure 13 also illustrates why the 100-MHz clocks that are routed on Layer 3 can not
get to the processor pins on either Layer 3 nor Layer 6. Thus, the two clocks transition to the secondary
side of the motherboard (not shown in Figure 13) to obtain the shortest vertical distance to the
processor’s BCLK[1:0] pins and the ITP_CLK[1:0] pins of the ITP700FLEX debug port. See Section
4.3.1 for further details.
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Figure 11. Intel 855PM MCH Source Synchronous Signals Recommended Escape Routing
Example
PRIMARY SIDE
LAYER 3
D[47:32]#
D[15:0]#
VCCGA VCCHA
1.8v Decap
VCCA=1.8v
A[16:3]#, REQ*#
HI 1.8v
Branch
PRIMARY SIDE
LAYER 6
100MHz
CLKs
D[63:48]#
D[31:16]#
1.2v
1.2v
855PM
855PM
MCH
Core
Core
A[31:17]#
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Figure 12. Processor Source Synchronous Signals Recommended Escape Routing Example
PRIMARY SIDE
LAYER 3
D[47:32]#
VCC-CORE
VCC-CORE
D[15:0]#
VCCP
VCCA=1.8v
A[16:3]#, REQ*#
VIAS to L3
VCCA=1.8v
PRIMARY SIDE
D[63:48]#
LAYER 6
VCC-CORE
D[31:16]#
VCCP
VCC-CORE
VCCA=1.8v
VIAS to L3
48
A[31:17]#
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Figure 13. Processor to Intel 855PM MCH Source Synchronous Signals Routing Example
L3
Intel® M
Pentium
Intel
Pentium
Pentium®
M
DATA
Mprocessor
processor
VCCORE
VCCCOR
1.8v
ADDRESS
Intel®
Intel
855PM
855PM
MCH-M
MCH-M
MCH
855PM
100MHz CLKs
DATA
L6
Intel®
Pentium
M
Intel
Pentium
Pentium®
M
Mprocessor
processor
1.2v
VCCCOR
VCCORE
Intel
Intel®
855PM
855PM
MCH-M
MCH-M
MCH
ADDRESS
855PM
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4.1.3.5.
Trace Length Equalization Procedures
The following example describes how to adjust a trace so that it will be length-matched to its reference.
A spreadsheet software program i.e. Microsoft* Excel* is used to facilitate the trace length matching
process. The layout editor used in this example is Allegro*. Figure 15 illustrates the trace length
matching procedure as described below:
1.
Cell B3 in Excel is preset to calculate the , which is the difference between the starting length
and reference length. This cell will calculate the function “B1 - B2.”
2.
Cell B4 calculates half of the which is equal to the value in Cell B3 divided by 2 This cell will
calculate the function “B3 / 2.”
Pre-route all the traces to approximately the same length using serpentines. The serpentines have
to use the same 1:3 spacing as the rest of the routing. It will be useful to make the traces 16 – 32
mils longer than needed in this stage. It is also important that there should be no 90 angles in the
serpertines.
Select the trace in the group of traces to be equalized that cannot be made any shorter. Taking
A[31:17]# as an example, in Figure 14 the longest trace that defines the reference length turns out
to be A29#. Note that there are no serpentines on this signal. Use the Allegro I (info) command to
report the reference length of the longest trace in the group. Record the reference length in cell B1
of Excel*.
3.
4.
Figure 14. Reference Trace Length Selection
A[31:17]#
50
A29#
Reference Length 5950mil
5.
Use the Allegro* I (info) command to report the current length of the trace to be equalized.
Record the length in cell B2 of the Excel* spreadsheet.
6.
Use the Allegro* “Cut” command to cut the trace in two locations of the serpentine as shown in
Figure 15. This will generate a floating section of the serpentine.
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7.
Use the Allegro* “Move ix” (i.e. if vertical routing) command to move the floating section by
the /2 distance listed in cell B4.
8.
Reconnect the floating segment if needed.
9.
Repeat steps 5 through 8 for the reminder of the traces in the group
Figure 15. Trace Length Equalization Procedures with Allegro*
CUT
REFERENCE LENGTH
STARTING LENGTH
∆
∆/2
5950
6012
-62
-31
Move ix - ∆/2
∆=Starting Length – Reference Length
4.1.4.
Asynchronous Signals
4.1.4.1.
Topologies
The following sections describe the topologies and layout recommendations for the Asynchronous Open
Drain and CMOS Signals found on the platform.
All Open Drain signals listed in the following sections below must be pulled-up to VCCP (1.05 V). If any
of these Open Drain signals are pulled-up to a voltage higher than VCCP, the reliability and power
consumption of the processor may be affected. Therefore, it is very important to follow the
recommended pull-up voltage for these signals.
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4.1.4.1.1.
Topology 1A: Open Drain (OD) Signal Driven by the Processor – IERR#
The Topology 1A OD signal IERR# should adhere to the following routing and layout
recommendations. Table 8 lists the recommended routing requirements for the IERR# signal of the
processor. The routing guidelines allow the signal to be routed as either micro-strip or strip-lines using
55 ± 15% characteristic trace impedance. Series resistor R1 is a dampening resistor for reducing
overshoot/undershoot reflections on the transmission line. The pull-up voltage for termination resistor
Rtt is VCCP (1.05 V). Due to the dependencies on system design implementation, IERR# can be
implemented in a number of ways to meet design goals. IERR# can be routed as a test point or to any
optional system receiver.
Figure 16. Routing Illustration for Topology 1A
Intel
Pentium M
processor
VCCP
System
Receiver
Rtt
L2
R1
L1
L3
Table 8. Layout Recommendations for Topology 1A
52
R1
Rtt
Transmission Line
Type
L1
L2
L3
0.5” – 12.0”
0” – 3.0”
0” – 3.0”
56
± 5%
56
± 5%
Micro-strip
0.5” – 12.0”
0” – 3.0”
0” – 3.0”
56
± 5%
56
± 5%
Strip-line
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4.1.4.1.2.
Topology 1B: Open Drain (OD) Signals Driven by the Processor – FERR# and
THERMTRIP#
The Topology 1B OD signals FERR# and THERMTRIP# should adhere to the following routing and
layout recommendations. Table 9 lists the recommended routing requirements for the FERR# and
THERMTRIP# signals of the processor. The routing guidelines allows the signals to be routed as either
micro-strips or strip-lines using 55 ± 15% characteristic trace impedance. Series resistor R1 is a
dampening resistor for reducing overshoot/undershoot reflections on the transmission line. The pull-up
voltage for termination resistor Rtt is VCCP (1.05 V).
Intel recommends that the FERR# signal of the processor be routed to the FERR# signal of the Intel
82801DBM ICH4-M. THERMTRIP# can be implemented in a number of ways to meet design goals. It
can be routed to the ICH4-M or any optional system receiver. Intel recommends that the THERMTRIP#
signal of the processor be routed to the THRMTRIP# signal of the ICH4-M. The ICH4-M’s
THRMTRIP# signal is a new signal to the I/O controller hub architecture that allows the ICH4-M to
quickly put the whole system into a S5 state whenever the catastrophic thermal trip point has been
reached.
If either FERR# or THERMTRIP# is routed to an optional system receiver rather than the ICH4-M and
the interface voltage of the optional system receiver does not support a 1.05-V voltage swing, then a
voltage translation circuit must be used. If the recommended voltage translation circuit described in
Section 4.1.4.2 is used, the driver isolation resistor shown in Figure 24, Rs, should replace the series
dampening resistor R1 in Topology 1B. Thus, it is important to note that R1 will no longer be required
in such a topology.
Figure 17. Routing Illustration for Topology 1B
Intel
Pentium M
processor
Intel ICH4-M
(or sys. receiver)
VCCP
Rtt
L2
R1
L1
L3
Table 9. Layout Recommendations for Topology 1B
L2
L3
0.5” – 12.0”
0” – 3.0”
0” – 3.0”
56
± 5%
56
± 5%
Micro-strip
0.5” – 12.0”
0” – 3.0”
0” – 3.0”
56
± 5%
56
± 5%
Strip-line
Intel® 855PM Chipset Platform Design Guide
R1
Rtt
Transmission Line
Type
L1
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4.1.4.1.3.
Topology 1C: Open Drain (OD) Signals Driven by the Processor – PROCHOT#
The Topology 1C OD signal PROCHOT#, should adhere to the following routing and layout
recommendations. Table 10 lists the recommended routing requirements for the PROCHOT# signal of
the processor. The routing guidelines allows the signal to be routed as either a micro-strip or strip-line
using 55 ± 15% characteristic trace impedance. Figure 18 shows the recommended implementation
for providing voltage translation between the processor’s PROCHOT# signal and a system receiver that
utilizes a 3.3-V interface voltage (shown as V_IO_RCVR).
Series resistor Rs is a component of the voltage translation logic and serves as a driver isolation resistor.
Rs is shown separated by distance L3 from the first bipolar junction transistor (BJT), Q1, to emphasize
the placement of Rs with respect to Q1. The placement of Rs a distance L3 before the Q1 BJT is a
specific implementation of the generalized voltage translator circuit shown in Figure 24. Rs should be
placed at the beginning of the T-split from the PROCHOT# signal. The pull-up voltage for termination
resistor Rtt is VCCP (1.05 V).
Intel recommends that PROCHOT# be routed using the voltage translation logic shown in Figure 18.
The receiver at the output of the voltage translation circuit can be any system receiver that can function
properly with the PROCHOT# signal given the nature and usage model of this pin. PROCHOT# is
capable of toggling hundreds of times per second to signal a hot temperature condition.
Figure 18. Routing Illustration for Topology 1C
3.3V
Intel
Pentium M
Processor
System Receiver
V_IO_RCVR
3.3V
VCCP
L1
L2
R2
R1
Rtt
L4
Q2
3904
Q1
L3
3904
Rs
Table 10. Layout Recommendations for Topology 1C
L1
54
L2
L3
L4
Rs
R1
R2-
Rtt
Transmission
Line Type
0.5” – 12.0” 0” – 3.0” 0” – 3.0” 0.5” – 12.0” 330
± 5% 1.3 k
± 5% 330
± 5% 56
± 5%
Micro-strip
0.5” – 12.0” 0” – 3.0” 0” – 3.0” 0.5” – 12.0” 330
± 5% 1.3 k
± 5% 330
± 5% 56
± 5%
Strip-line
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4.1.4.1.4.
Topology 2A: Open Drain (OD) Signal Driven by Intel 82801DBM ICH4-M –
PWRGOOD
The Topology 2A OD signal PWRGOOD driven by the Intel 82801DBM ICH4-M (processor CMOS
signal input) should adhere to the following routing and layout recommendations. Table 11 lists the
recommended routing requirements for the PWRGOOD signal of the processor. The routing guidelines
allows the signal to be routed as either micro-strip or strip-lines using 55 ± 15% characteristic trace
impedance. The pull-up voltage for termination resistor Rtt is VCCP (1.05 V). Note that the Intel ICH4M’s CPUPWRGD signal should be routed point-to-point to the processor’s PWRGOOD signal. The
routing from the processor’s PWRGOOD pin should fork out to both to the termination resistor, Rtt, and
the ICH4-M. Segments L1 and L2 from Figure 19 should not T-split from a trace from the processor
pin.
Figure 19. Routing Illustration for Topology 2A
VCCP
Intel
Pentium M
processor
Rtt
Intel
ICH4-M
L2
L1
Table 11. Layout Recommendations for Topology 2A
L1
L2
0.5” – 12.0”
0” – 3.0”
330
± 5%
Micro-strip
0.5” – 12.0”
0” – 3.0”
330
±5%
Strip-line
Intel® 855PM Chipset Platform Design Guide
Rtt
Transmission Line Type
55
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4.1.4.1.5.
Topology 2B: CMOS Signals Driven by Intel 82801DBM ICH4-M – DPSLP#
The Topology 2B CMOS DPSLP# signal driven by the Intel 82801DBM ICH4-M ( processor CMOS
signal input) should adhere to the following routing and layout recommendations illustrated in Figure
20. As listed in Table 12, the L1 and L2 segments of the DPSLP# signal topology can be routed as either
micro-strip or strip-lines using 55 ± 15% characteristic trace impedance. Note that the ICH4-M’s
DPSLP# signal should be routed point-to-point with the daisy chain topology shown. The routing of
DPSLP# at the processor should fork out to both the ICH4-M and the Intel 855PM MCH. Segments L1
and L2 from Figure 20 should not T-split from a trace from the processor pin.
Figure 20. Routing Illustration for Topology 2B
Intel
Pentium M
processor
Intel 855PM
MCH
Intel
ICH4-M
L2
L1
Table 12. Layout Recommendations for Topology 2B
L1
L2
Transmission Line Type
0.5” – 12.0”
0.5” – 6.5”
Micro-strip
0.5” – 12.0”
0.5” – 6.5”
Strip-line
Figure 21 illustrates a DPSLP# signal routing example to conform to Topology 2B recommendations.
The routing starts from the ICH4-M’s DPSLP# signal on the secondary side layer of the motherboard to
the processor ’s DPSLP# pin. The dog bone via allows switching of the routing layer to Layer 6 thereby
allowing routing to the Intel 855PM MCH’s DPSLP# pin located in the same cluster as the remaining
common clock signals routed between the processor and MCH. The routing layer change from the
secondary side to Layer 6 using the processor DPSLP# pin dog bone via is strongly advised to avoid any
stub tapering of the CPU connection off of the ICH4-M to MCH connection to minimize transmission
line effects.
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Figure 21. DPSLP# Layout Routing Example
Intel Pentium M
Pentium
M
processor
COMMON
Clock Signals
855PM
Intel 855PM
855PM
Intel
MCH-M
MCH
L6
DPSLP#
From
Secondary Side
Intel® 855PM Chipset Platform Design Guide
From
Intel
ICH4-M
ICH4-M
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4.1.4.1.6.
Topology 2C: CMOS Signals Driven by Intel 82801DBM ICH4-M – LINT0/INTR,
LINT1/NMI, A20M#, IGNNE#, SLP#, SMI#, and STPCLK#
The Topology 2C CMOS LINT0/INTR, LINT1/NMI, A20M#, IGNNE#, SLP#, SMI#, and STPCLK#
signals should implement a point-to-point connection between the Intel 82801DBM ICH4-M and the
processor. The routing guidelines allow both signals to be routed as either micro-strip or strip-lines
using 55 ± 15% characteristic trace impedance. No additional motherboard components are necessary
for this topology.
Figure 22. Routing Illustration for Topology 2C
Intel
Pentium M
processor
Intel
ICH4-M
L1
Table 13. Layout Recommendations for Topology 2C
58
L1
Transmission Line Type
0.5” – 12.0”
Micro-strip
0.5” – 12.0”
Strip-line
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4.1.4.1.7.
Topology 3: CMOS Signals Driven by Intel 82801DBM ICH4-M to Processor and
FWH – INIT#
The signal INIT# should adhere to the following routing and layout recommendations. Table 14 lists the
recommended routing requirements for the INIT# signal of the ICH4-M. The routing guidelines allow
both signals to be routed as either micro-strip or strip-lines using 55 ± 15% characteristic trace
impedance. Figure 23 shows the recommended implementation for providing voltage translation
between the ICH4-M’s INIT# voltage signaling level and any firmware hub (FWH) that utilizes a 3.3 V
interface voltage (shown as a supply V_IO_FWH). See Section 4.1.4.2 for more details on the voltage
translator circuit. For convenience, the entire topology and required transistors and resistors for the
voltage translator is shown in Figure 23.
Series resistor Rs is a component of the voltage translator logic circuit and serves as a driver isolation
resistor. Rs is shown separated by distance L3 from the first bipolar junction transistor (BJT), Q1, to
emphasize the placement of Rs with respect to Q1. The placement of Rs a distance of L3 before the Q1
BJT is a specific implementation of the generalized voltage translator circuit shown in Figure 24. The
routing recommendations of transmission line L3 in Figure 23 is listed in Table 14 and Rs should be
placed at the beginning of the T-split of the trace from the ICH4-M’s INIT# pin.
Figure 23. Routing Illustration for Topology 3
Intel
FWH
3.3V
V_IO_FWH
3.3V
Intel
ICH4-M
Intel
Pentium M
processor
R2
R1
L4
Q2
L1
L2
3904
Q1
L3
3904
Rs
Table 14. Layout Recommendations for Topology 3
Rs
R1
R2
Transmission Line
Type
L1 + L2
L3
L4
0.5” – 12.0”
0” – 3.0”
0.5” – 6.0”
330
± 5%
1.3 k
± 5%
330
± 5%
Micro-strip
0.5” – 12.0”
0” – 3.0”
0.5” – 6.0”
330
± 5%
1.3 k
± 5%
330
± 5%
Strip-line
For details on INIT# assertion/deassertion timings, see Section 9.7.5 for more details.
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4.1.4.2.
Voltage Translation Logic
A voltage translation circuit or component is required on any signals where the voltage signaling level
between two components connected by a transmission line may cause unpredictable signal quality. The
recommended voltage translation circuit for the platform is shown in Figure 24. For the INIT# signal
(Section 4.1.4.1.7), a specialized version of this voltage translator circuit is used where the driver
isolation resistor, Rs, is place at the beginning of a transmission line that connects to the first bipolar
junction transistor, Q1. Though the circuit shown in Figure 24 was developed to work with signals that
require translation from a 1.05-V to a 3.3-V voltage level, the same topology and component values, in
general, can be adapted for use with other signals as well provided the interface voltage of the receiver
is also 3.3 V. Any component value changes or component placement requirements for other signals
must be simulated in order to guarantee good signal quality and acceptable performance from the circuit.
In addition to providing voltage translation between driver and receiver devices, the recommended
circuit also provides filtering for noise and electrical glitches. A larger first-stage collector resistor, R1,
can be used on the collector of Q1, however, it will result in a slower response time to the output falling
edge. In the case of the INIT# signal, resistors with values as close as possible to those listed in Figure
24 should be used without exception.
With the low 1.05-V signaling level of the FSB, the voltage translation circuit provides ample isolation
of any transients or signal reflections at the input of transistor Q1 from reaching the output of transistor
Q2. Based on simulation results, the voltage translation circuit can effectively isolate transients as large
as 200 mV and that last as long as 60 ns.
Figure 24. Voltage Translation Circuit
3.3V
3.3V
1.3K ohm
+/- 5%
From Driver
330 ohm
+/- 5%
R2
Q2
To Receiver
3904
Q1
Rs
4.1.5.
R1
330 ohm
+/- 5%
3904
Processor RESET# Signal
The RESET# signal is a common clock signal driven by the Intel 855PM MCH CPURST# pin. In a
production system where no ITP700FLEX debug port is implemented, a simple point-to-point
connection between the CPURST# pin of the MCH and processor’s RESET# pin is recommended (see
Figure 25). On-die termination of the AGTL+ buffers on both the processor and the MCH provide
proper signal quality for this connection. This is the same case as for the other common clock signals
listed in Section 4.1.2. Length L1 of this interconnect should be limited to minimum of 1 inch and
maximum of 6.5 inches.
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Figure 25. Processor RESET# Signal Routing Topology with NO ITP700FLEX Connector
Intel
Pentium M
processor
Intel
855PM
MCH
L1
For a system that implements an ITP700FLEX debug port a more elaborate topology is required in order
to guarantee proper signal quality at both the processor signal pad and the ITP700FLEX input receiver.
In this case the topology illustrated in Figure 26 should be implemented. The CPURST# signal from the
MCH should fork out (do not route one trace from MCH pin and then T-split) towards the processor’s
RESET# pin as well as towards the Rtt and Rs resistive termination network placed next to the
ITP700FLEX debug port connector. Rtt (54.9 ± 1%) pulls-up to the VCCP voltage and is placed at the
end of the L2 line that is limited to a 12-inch maximum length. Rs (22.6 ± 1%) should be placed right
next to Rtt to minimize the routing between them in the vicinity of the ITP700FLEX connector to limit
the L3 length to less than 0.5 inches. ITP700FLEX operation requires the matching of L2 + L3 - L1
length to the length of the BPM[4:0]# signals length within ± 50 ps. Refer to Section 4.3.1 for more
details on ITP700FLEX signal routing and Section 4.1.1.4 for more details on signal propagation time to
distance correlation. See Table 15 for routing length summary and termination resistor values.
Currently 1% tolerance resistors are recommended for Rs and Rtt. The use of 5% tolerant resistors for
these resistors and whether it could provide adequate signal quality performance is under investigation.
Figure 26. Processor RESET# Signal Routing Topology With ITP700FLEX Connector
Intel
Pentium M
processor
L1
Intel 855PM
MCH
RESET#
CPURESET#
VCCP
Rtt
L2
Intel® 855PM Chipset Platform Design Guide
Rs
ITPFLEX
CONNECTOR
L3
RESET#
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Table 15. Processor RESET# Signal Routing Guidelines with ITP700FLEX Connector
4.1.5.1.
L1
L2 + L3
L3
1.0” – 6.0”
12.0” max
0.5” max
Rs
Rs = 22.6
Rtt
± 1%
Rtt = 54.9
± 1%
Processor RESET# Routing Example
Figure 27 illustrates a board routing example for the RESET# signal with an ITP700FLEX debug port
implemented. Figure 27 illustrates how the CPURST# pin of Intel 855PM MCH forks out into two
branches on Layer 6 of the motherboard. One branch is routed directly to the processor’s RESET# pin
amongst the rest of the common clock signals. Another branch routes below the address signals and vias
down to the secondary side that route to the Rs and Rtt resistors. These resistors are placed in the
vicinity of the ITP700FLEX debug port. Note the placement of Rs and Rtt next to each other to
minimize the routing between Rs and Rtt as well as the minimal routing between Rs and the
ITP700FLEX connector. Also, since a transition between Layer 6 and the secondary side occurs, a GND
stitching via is added to guarantee continuous ground reference of the secondary side routing of the
RESET# signal to ITP700FLEX connector.
Figure 27. Processor RESET# Signal Routing Example with ITP700FLEX Debug Port
FO R K
Intel M
855P
Layer 6
COMMON
C lock S ignals
Pentium M
PIntel
entium
M
processor
S econdary
S ide
855PM
M C H-M
R tt
GND
VIA
ADDR
Rs
CPU
L1
MC H-M
RES ET#
CPURE SET #
VC C P
Rtt
L2
62
Rs
L3
ITP FLEX
connector
VC C P
ITP FLE X
CO NNECTO R
RES ET#
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4.1.6.
Processor and Intel 855PM MCH Host Clock Signals
Figure 28 illustrates processor and Intel 855PM MCH host clock signal routing. Both the processor and
the MCH’s BCLK[1:0] signals are initially routed from the CK-408 clock generator on Layer 3. Figure
13 shows how vertical routing on both Layer 3 and Layer 6 is blocked by the FSB address signals’
horizontal routing. Thus, a transition to secondary side layer routing is needed to complete the
BCLK[1:0] routing to the processor’s pins. In the recommended routing example (Figure 28) secondary
side layer routing of BCLK[1:0] is 507 mils long. To meet length-matching requirements between the
processor and MCH’s BCLK[1:0] signals, a similar transition from Layer 3 to the secondary side layer
is done next to the MCH package outline. Routing of the MCH’s BCLK[1:0] signals on the secondary
side is also trace tuned to 507 mils. BCLK[1:0] layer transition vias are accompanied by GND stitching
vias. For similar reasons, routing for the ITP interposer’s BCLK[1:0] signals also transition from Layer
3 to the secondary side layer and have 507-mil long traces on this layer. Throughout the routing length
on Layer 3, BCLK[1:0] signals should reference a solid GND plane on Layer 2 and Layer 4 as shown in
Figure 10. See Section 10.2.1 for more details on host clock topologies and routing recommendations.
If a system supports either the on-board ITP700FLEX connector or ITP Interposer only, then differential
host clock routing to either the ITP700FLEX connector or CPU socket but not both, is required.
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Figure 28. Processor and Intel 855PM MCH Host Clock Layout Routing Example
Secondary
Side
GND
Via
Intel 855PM
MCH-M
MCH
855PM
L3
Pentium
M
processor
Intel Pentium M
855PM
855PM MCH
BCLK[1:0]
BCLK[1:0]
507mil on
on L8
L8
507mil
Pentium M
BCLK[1:0]
507mil on L8
ITP
INTERPOSER
BCLK[1:0]
507mil on L8
ITP
BCLK[1:0]
ITP
FLEX
FROM
CK-408
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4.1.7.
GTLREF Layout and Routing Recommendations
There is one AGTL+ reference voltage pin on the processor, GTLREF, which is used to set the
reference voltage level for the AGTL+ signals (GTLREF). The reference voltage must be supplied to the
GTLREF signal, pin AD26 of the processor pin-map. The voltage level that needs to be supplied to
GTLREF must be equal to 2/3 * VCCP ± 2%. The Intel 855PM MCH also requires a reference voltage
(MCH_GTLREF) to be supplied to its HVREF[4:0] pins. The GTLREF voltage divider for both the
processor and MCH cannot be shared. Thus, both the processor and MCH must have their own locally
generated GTLREF networks. Figure 29 shows the recommended topology for generating GTLREF for
Intel Pentium M processor using a R1 = 1 k ± 1% and R2 = 2 k ± 1% resistive divider.
Since the input buffer trip point is set by the 2/3* VCCP on GTLREF and to allow tracking of VCCP
voltage fluctuations, no decoupling should be placed on the GTLREF pin. The node between R1 and R2
(GTLREF) should be connected to the GTLREF pin of processor with a Zo = 55 trace shorter than
0.5 inches. Space any other switching signals away from GTLREF with a minimum separation of 25
mils. Do not allow signal lines to use the GTLREF routing as part of their return path (i.e. do not allow
the GTLREF routing to create splits or discontinuities in the reference planes of the FSB signals).
Figure 29. Processor GTLREF Voltage Divider Network
+VCCP
R1
1K
1%
< 1/2"
Zo = 55Ω trace
GTLREF
R2
2K
1%
GTLREF
(pin AD26)
RSVD
(pin E26)
Intel® 855PM Chipset Platform Design Guide
Intel
Pentium M
processor
RSVD
(pin AC1)
RSVD
(pin G1)
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A recommended layout of GTLREF for the processor is shown in Figure 30. To avoid interaction with
FSB routing and power delivery, GTLREF’s R1 and R2 components are placed next to each other on the
primary side of the motherboard and connected with a Zo = 55 370-mil long trace to the GTLREF pin
on processor, which meets the 0.5-inch maximum length requirement. The BGA ball lands on the
primary side for the RSVD signal pins E26, G1, and AC1 are shown for illustrative purposes and are not
routed.
Figure 30. Processor GTLREF Motherboard Layout
Pin AG1
R1
VCCP
R2
GTLREF
Zo=55Ω
<0.5”
Intel
Pentium
Pentium M
M
processor
Pin E26
PRIMARY SIDE
Pin G1
A recommended MCH_GTLREF generation circuit for the Intel 855PM MCH is shown in Figure 31.
The circuit includes a resistive divider network with R1 = 49.9 ± 1% and R2 = 100 ± 1% and three
decoupling capacitors C1 = C2 = 200 pF and C3 = 1 F all bypassed to GND. The MCH_GTLREF
voltage connects to five Intel 855PM MCH HVREF pins: AB16, AB12, AA9, P8, and M7.
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Figure 31. Intel 855PM MCH HVREF[4:0] Reference Voltage Generation Circuit
+VCCP
R1
Ω
1%
MCH_GTLREF
R2
Ω
1%
AB16
AB12
C1
200 pF
C2
200 pF
C3
1 uF
AA9
P8
M7
HVREF
HVREF
HVREF
HVREF
Intel
855PM
MCH
HVREF
A recommended layout for the MCH_GTLREF generation circuit is shown in Figure 32. The
MCH_GTLREF generation circuit components are located on the secondary side to minimize
motherboard space usage and optimize robustness of the connection. Each of the AB16, AB12, and P8
HVREF pins has a decoupling capacitor (C1, C2, and C3) next to them. GND side of the C1, C2, and
C3 capacitors is connected to the GND flood on the secondary side and stitched with vias to internal
GND planes. R1 is placed next to pin AB16 and R2 is placed next to pin P8. Layer 3 of the motherboard
shorts the two clusters of HVREF pins P8, M7, AB16, AB12, and AA9. The two clusters are further
shorted on the primary side layer.
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Figure 32. Intel 855PM MCH HVREF[4:0] Motherboard Layout
PRIMARY SIDE
1.8v
LAYER 3
MCH_GTLREF
PRIMARY SIDE
C1
R1
SECONDARY SIDE
C3
R2
C2
MCH_GTLREF
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4.1.8.
AGTL+ I/O Buffer Compensation
The processor has four pins, COMP[3:0], and the Intel 855PM MCH has two pins, HRCOMP[1:0], that
require compensation resistors to adjust the AGTL+ I/O buffer characteristics to specific board and
operating environment characteristics. Also, the MCH requires two special reference voltage generation
circuits to pins HSWNG[1:0] for the same purpose described above. Refer to the Intel® Pentium M
Processor Datasheet, Intel® Celeron M Processor Datasheet, Intel® Pentium® M Processor on 90nm
process with 2-MB L2 Cache Datasheet, and Intel® 855PM Memory Controller Hub (MCH)
DDR200/266MHz Datasheet for details on resistive compensation.
4.1.8.1.
Processor AGTL+ I/O Buffer Compensation
For the processor, the COMP[2] and COMP[0] pins must each be pulled-down to ground with 27.4 ±
1% resistors and should be connected to the processor with a Zo = 27.4 trace that is less than 0.5
inches from the processor pins. The COMP[3] and COMP[1] pins must each be pulled-down to ground
with 54.9 ± 1% resistors and should be connected to the processor with a Zo = 55 trace that is less
than 0.5 inches from the processor pins.. COMP[3:0] traces should be at least 25 mils (> 50 mils
preferred) away from any other toggling signal.
The recommended layout of the processor COMP[3:0] resistors is illustrated in Figure 33. To avoid
interaction with FSB routing on internal layers and VCCA power delivery on the primary side, Layer 1,
COMP[1:0] resistors are placed on the secondary side. Ground connections to the COMP[1:0] resistors
use a small ground flood on the secondary side layer and connect only with a single GND via to stitch
the GND planes. The compact layout as shown in Figure 33 should be used to avoid excessive
“perforation” of the VCCP plane power delivery. Figure 33 illustrates how a 27.4- resistor connects
with an ~18-mil wide (Zo = 27.4 ) and 160-mil long trace to COMP0. Necking down to 14 mils is
allowed for a short length to pass in between the dog bones. The 54.9- resistor connects with a regular
5-mil wide (Zo = 55 ) and 267-mil long trace to COMP1.
Placement of COMP[1:0] on the primary side is possible as well. An alternative placement
implementation is shown if Figure 34.
To minimize motherboard space usage and produce a robust connection, the COMP[3:2] resistors are
also placed on the secondary side (Figure 33, right side). A 27.4- resistor connects with an 18-mil
wide (Zo = 27.4 ) and 260-mil long trace to COMP2. Necking down to 14 mils is allowed for a short
length to pass in between the dog bones. Notice that the COMP2 (Figure 33, left side) dog bone trace
connection on the primary side is also widened to 14 mils to meet the Zo = 27.4- characteristic
impedance target. The right side of Figure 33 also illustrates how the 54.9 ± 1% resistor connects with
a regular 5-mil wide (Zo = 55 ) and 100-mil long trace to COMP3. The ground connection of
COMP[3:2] is done with a small flood plane on the secondary side that connects to the GND vias of
pins AA1 and Y2 of the processor pin-map. This is done to avoid via interaction with the FSB routing
on Layer 3 and Layer 6.
For COMP2 and COMP0, it is extremely important that 18-mil wide dog bone connections on the
primary side and 18-mil wide traces on the secondary sides be used to connect the signals to
compensation resistors on the secondary side. The use of 18-mil wide dog bones and traces is used to
achieve the Zo = 27.4 target to ensure proper operation of the FSB. See Figure 35 for more details.
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Figure 33. Processor COMP[3:0] Resistor Layout
Pin AG1
COMP[2]
COMP[3]
VCCP to
855PM
AA1
Y2
GND
pins
COMP[0]
VCCP
COMP[1]
VCCP
One GND Via
VCCA=1.8v
PRIMARY SIDE
SECONDARY SIDE
Figure 34. Processor COMP[1:0] Resistor Alternative Primary Side Layout
PRIMARY SIDE
VCCA=1.8v
COMP[1]
GND
VCCP
Via
COMP[0]
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Figure 35. Processor COMP[2] and COMP[0] 18-Mil Wide Dog Bones and Traces
PRIMARY SIDE
COMP0
SECONDARY SIDE
27.4Ω 1%
COMP1
18-mil Dog Bone
PRIMARY SIDE
COMP2
18-mil Trace
SECONDARY SIDE
COMP3
27.4Ω 1%
4.1.8.2.
Intel 855PM MCH AGTL+ I/O Buffer Compensation
The Intel 855PM MCH AGTL+ I/O buffer resistive compensation signals pins of the MCH,
HRCOMP[1:0], should each be pulled-down to ground with a 27.4 ± 1% resistor. The maximum trace
length from pin to resistor should be less than 0.5 inches long and includes the dog bone connection on
the primary side from the BGA land to the dog bone via. This < 0.5 inch long connection should be 18
mils wide to achieve the Zo = 27.4 target. Also, the routing for HRCOMP should be at least 25 mils
away from any switching signal. Figure 36 illustrates the recommended layout for the Intel 855PM
MCH HRCOMP[1:0] resistors that are placed on the motherboard’s secondary side to save space as well
as to make the shortest possible connection without interacting with FSB routing. To avoid GND via
interaction of the HRCOMP[1:0] resistors, each should share the ground pin vias of the MCH’s AE1
and AD12 ground pins to make the ground connection.
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Figure 36. Intel 855PM MCH HRCOMP[1:0] Resistor Layout
SECONDARY SIDE AD12
Pin
GND
Via
AE1
Pin
GND
Via
HRCOMP[0]
HRCOMP[1]
The MCH’s AGTL+ I/O buffer resistive compensation mechanism also requires the generation of
reference voltages to the HSWNG[1:0] pins with a value of 1/3* VCCP. The schematics for
HSWNG[1:0] voltage generation is illustrated in Figure 37. Two resistive dividers with R1a = R1b =
301 ± 1% and R2a = R2b = 150 ± 1% generate the HSWNG[1:0] voltages. C1a = C1b = 0.01 µF
act as decoupling capacitors and connect HSWNG[1:0] to VCCP. HSWNG components should be placed
within 0.5 inches of their respective pins and connected with a 15-mil wide trace. To avoid coupling
with any other signals, maintain a minimum of 25 mils of separation to other signals.
Figure 37. Intel 855PM MCH HSWNG[1:0] Reference Voltage Generation Circuit
+VCCP
R1a
301Ω
1%
+VCCP
C1a
0.1uF
C1b
0.1 uF
HSWNG[0]
R2a
150Ω
1%
HSWNG[0]
R1b
301
1%
HSWNG[1]
Intel
855PM
MCH
HSWNG[1]
R2b
150
1%
Figure 38 illustrates recommended layout for the HSWNG[1:0] components that are placed on the
secondary side to minimize their interconnect length and space they occupy. In the example, C1a and
C1b are placed closer to HSWNG pins than R1a, R1b, R2a, and R2b. It is important to keep only the
connection of C1a and C1b to the HSWNG[1:0] with a 15-mil wide trace. The R1a (R1b) to R2a (R2b)
connection can be done with a narrow trace as well as the connection to the pin that in the layout
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example below is done by means of a via to Layer 6 and a short trace from the via to the dog bone via of
HSWNG[1:0] pin as illustrated on the right side of Figure 38.
Figure 38. Intel 855PM MCH HSWNG[1:0] Layout
C1b
HSWNG1
R2b
R1b
C1a
HSWNG0
R2a
R1a
SECONDARY SIDE
4.1.9.
L6
Processor FSB Strapping
The Intel Pentium M processor / Intel Celeron M processor and Intel 855PM MCH both have pins that
require termination for proper component operation.
1.
2.
3.
For the processor, a stuffing option should be provided for the TEST[3:1] pins to allow a 1-k ±
5% pull-down to ground for testing purposes. For proper processor operation, the resistor should
not be stuffed. Resistors for the stuffing option on these pins should be placed within 2.0 inches of
the processor. Figure 39 illustrates the recommended layout for the stuffing options. For normal
operation, these resistors should not be stuffed.
For the MCH, the ST[1] signal does not require an external pull-up for normal operation. This
signal has an internal pull-up that straps the FSB for 100-MHz operation. However, a stuffing
option for a 1-k ± 5% pull-up to a 1.5-V source can be provided for testing purposes. For details
on the ST[0] signal, refer to Section 6.3.
The processor’s ITP signals, TDI, TMS, TRST and TCK should assume default logic values even
if the ITP debug port is not used. The TDO signal may be left open or no connect in this case.
Table 16 summarizes the default strapping resistors for these signals. These resistors should be
connected to the processor within 2.0 inches from their respective pins. It is important to note that
Table 16 is applicable only when neither the onboard ITP nor ITP interposer are planned to be
used. See Section 4.2 on cautions against designs with lack of debug tools support. Intel does not
recommend use of the ITP interposer debug port if there is a dependence only on the motherboard
termination resistors. The signals below should be isolated from the motherboard via specific
termination resistors on the ITP interposer itself per interposer debug port recommendations. For
the case where the onboard ITP700FLEX debug port is used refer to Section 4.3 for default
termination recommendations.
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Table 16. ITP Signal Default Strapping When ITP Debug Port Not Used
Signal
Resistor Value
Connect To
Resistor Placement
TDI
150
± 5%
VCCP
Within 2.0” of the CPU
TMS
39
± 5%
VCCP
Within 2.0” of the CPU
TRST#
680
± 5%
GND
Within 2.0” of the CPU
TCK
27
± 5%
GND
Within 2.0” of the CPU
NC
N/A
TDO
Open
Figure 39 illustrates the recommended layout for the processor’s strapping resistors. To avoid
interaction with FSB routing, the TEST[3:1] signal resistors are placed on the secondary side of the
motherboard. To avoid GND via interaction with the FSB routing, the resistors share GND via
connections with the A8, A17, and A20 ground pins of the processor.
The 150- pull-up resistor to VCCP (1.05 V) for TDI is shown in Figure 39 on the secondary side of the
board. The placement of the strapping resistors for TDI, TMS, TRST#, and TCK is not critical.
Figure 39. Processor Strapping Resistor Layout
SECONDARY SIDE
TEST[2]
A8, A17 & A20
GND
Pins
TEST[3]
74
TEST[1]
TDI
TMS
TRST#
TCK
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4.1.10.
Processor VCCSENSE/VSSSENSE Design Recommendations
The VCCSENSE and VSSSENSE signals of the processor provide isolated, low impedance connections
to the processor’s core power (VCC) and ground (VSS). These pins can be used to sense or measure
power (VCC) or ground (VSS) near the silicon with little noise. To make them available for
measurement purposes, it is recommended that VCCSENSE and VSSSENSE both be routed with a Zo =
55 ± 15% trace of equal length. Use 3:1 spacing between the routing for the two signals and all other
signals should be a minimum of 25 mils (preferably 50 mils) from VCCSENSE and VSSSENSE
routing. Terminate each line with an optional (default is No Stuff) 54.9 ± 1% resistor. Also, a ground
via spaced 100 mils away from each of the test point vias for VCCSENSE and VSSSENSE should be
added. A third ground via should also be placed in between them to allow for a differential probe
ground. See Figure 40 for the recommended layout example.
Figure 40. VCCSENSE/VSSSENSE Routing Example
VCCSENSE
GND
54.9Ω
54.9Ω
VSSSENSE
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4.2.
Intel System Validation Debug Support
In any PC design, it is critical to enable industry-standard tools to allow for debug of a wide range of
issues that arise in the normal design cycle. In a mobile design, electrical/logic visibility is very limited,
and often making progress on debugging such issues is very time consuming. In some cases progress is
not possible without board redesign or extensive rework. Two topics in particular are very important to
general system debug capabilities: ITP support and processor logic analyzer support (FSB LAI)
4.2.1.
In Target Probe (ITP) Support
4.2.1.1.
Background and Justification
The In Target Probe (ITP) is needed to debug BIOS, logic, signal integrity, general software, and
general hardware issues involving CPUs, chipsets, SIOs, PCI devices, and other hardware in a design.
The ITP is widely used by validation, test, and debug groups within Intel (as well as by third party BIOS
vendors, OEMs, and other developers).
Note: Any Intel 855PM chipset based systems designed without ITP support may prevent assistance from
various Intel validation, test, and debug groups. For this reason, it is critical piece that ITP support is
provided. This can be done with zero additional BOM cost, and very minimal layout/footprint costs.
However, the cost for not providing this support can be anywhere from none (if there are no blocking
issues found in the system design) to schedule slips of a month or more. The latter scenario represents
the time needed to spin a board design and required assembly time to add an ITP port when it is
absolutely required and other mechanical and routing issues prevent the use of an ITP interposer, if one
exists.
4.2.1.2.
Implementation
To minimize the ITP connector footprint, the ITP700FLEX alternative is a better option for mobile
designs. Note that the termination values do not need to be stuffed (thus zero additional BOM cost).
However, standard signal connection guidelines for the CPU’s TAP logic signals for the non-ITP case
still need to be followed. In other words, only the traces and component footprints need to be added to
the design, with all previous “non-ITP” guidelines followed otherwise. This way, when ITP support is
needed, the termination values and connector can be populated as needed for debug support. Note also
that if the ITP700FLEX footprint cannot be followed due to mechanical, routing, or footprint reasons, it
is acceptable to have a simple via grouping in lieu of the connector to allow for “blue-wiring” of the
ITP. This assumes that all signal topology and routing guidelines are still adhered to on the motherboard
and the “blue-wiring” from the signal vias to the ITP700FLEX connector is as short as possible.
4.2.2.
Processor Logic Analyzer Support (FSB LAI)
4.2.2.1.
Background and Justification
The second key tool that is needed to debug BIOS, logic, signal integrity, general software, and general
hardware issues involving CPUs, chipsets, SIOs, PCI devices, and other hardware in platform design is
the FSB Logic Analyzer probe (FSB LAI). This critical tool is widely used by various validation, test,
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and debug groups within Intel (as well as by third party BIOS vendors, OEMs, and other developers).
For the Intel Pentium M and Intel Celeron M processors, Agilent* Corporation will develop this tool
and will likely be the only visibility to this critical system bus.
Note: Any Intel 855PM chipset based systems designed without FSB LAI support may severely limit the
ability of various Intel validation, test, and debug groups from debugging various issues in a reasonable
amount of time.
For this reason, it is critical that FSB LAI support is provided. There are two primary pieces to
providing this support:
4.2.2.2.
1.
Providing a motherboard with a processor socket. The FSB LAI is an interposer that plugs into
the CPU socket, and the CPU then plugs into the LAI. The use of non-standard sockets may
also prohibit the LAI from working as the locking mechanism may become inaccessible. It is
important to check the LAI design guidelines to ensure a particular socket will work. Note that
the LAI was designed to accommodate the most common (and at the time the only known) Intel
Pentium M processor sockets on the market.
2.
Observing FSB LAI keepout requirements. There are several options to achieving this.
Removing the motherboard from the case is typically the first step to meeting keepout
requirements. If any components that would otherwise be in the keepout area can be relocated
for debug purposes (i.e. axial lead devices that can be de-soldered and re-soldered to the other
side of the board, parts that can be removed and blue-wired further away, etc.) that is also an
acceptable method of meeting keepout requirements. If keepouts still can not be met, Intel
strongly recommends that a separate debug motherboard be built which has the same bill of
material (BOM) and Netlist, but with FSB LAI keepout requirements met (this also gives the
opportunity to add other test-points).
Implementation
Details from Agilent* Corporation on the FSB LAI mechanicals (i.e. design guide with keepout volume
info) are currently available for ordering. Please contact your local Intel field representative on how to
obtain the latest design info. See Section 4.3.1.4 for more details.
4.2.3.
Intel Pentium M Processor and Intel Celeron M Processor OnDie Logic Analyzer Trigger Support (ODLAT)
The Intel Pentium M and Intel Celeron M processor provides support for three address/data recognizers
on-die for setting on-die logic analyzer triggers (ODLAT) or breakpoints. Details from American
Arium* on the ODLAT are currently available for ordering.
4.3.
Onboard Debug Port Routing Guidelines
For systems incorporating the Intel Pentium M and Intel Celeron M processors, the debug port should be
implemented as either an onboard debug port or via an interposer. Please reference the document
ITP700 Debug Port Design Guide, which can be found on
http://www.intel.com/design/Xeon/guides/24967912.pdf, for the most up to date information.
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4.3.1.
Recommended Onboard ITP700FLEX Implementation
4.3.1.1.
ITP Signal Routing Guidelines
Figure 41 illustrates recommended connections between the onboard ITP700FLEX debug port,
processor, Intel 855PM MCH, and CK-408 clock chip in the cases where the debug port is used.
For the purpose of this discussion on ITP700FLEX signal routing, refer to Section 4.1.1.4 for more
details on the signal propagation time to distance relationships for the length matching requirements
listed as periods of time below. It is understood that the time to distance relationships mentioned in
Section 4.1.1.4 apply to the specific assumptions made only and it is the responsibility of the system
designer to determine what is the appropriate length that correlates to the listed time periods as length
matching requirements.
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Figure 41. ITP700FLEX Debug Port Signals
L8
BCLKp
1.05v
ITPCLK[1:0]
L6
BaniasCLK[1:0]
TDI
BCLK[1:0]
TRST#
L7
Intel
Pentium M
processor
TCK
TDI
TMS
TMS
TRST#
OdemCLK[1:0]
CK 408
39.2Ω
1%
150Ω
5%
TDI
TMS
BCLKn
1.05v
TRST#
1.05v
680Ω
5%
FBO
TCK
TCK
54.9Ω
22.6Ω L1
1%
1% TDOITP
TDO
BCLK[1:0]
BPM[3:0]#
PRDY#
Intel
855PM
MCH
L2
BPM[3:0]#
240Ω
1.05v 5%
PREQ# BPM[5]#
RESET#
CPURESET#
RESET#
L3
TDO
VCC
240Ω
5%
DBR#
54.9Ω
1%
L5
TCK
BPM[5:0]#
VCC
BPM[4]#
FBO
27.4Ω
1%
1.05v
TDO
TRST#
VTT
VTT
VTAP
0.1uF
FBO
TDI
TMS
DBA#
RESETITP#
22.6Ω
1%
RESET#
L4
DBR#
DBA#
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To connect to the debug port, follow the steps below:
Route the TDI signal between the ITP700FLEX connector and the processor. A 150up to VCCP (1.05 V) should be placed within ± 300 ps of the TDI pin.
± 5% pull-
Route the TMS signal between ITP700FLEX connector and the processor. A 39.2to VCCP should be placed within ± 200 ps of the ITP700FLEX connector pin.
± 1% pull-up
Route the TRST# signal between ITP700FLEX connector and the processor. A 510- to 680- ±
5% pull-down to ground should be placed on TRST#. Placement of the pull down resistor is not
critical. Avoid having any trace stub from the TRST# signal line to the termination resistor.
Route the TCK signal from the ITP700FLEX connector’s TCK pin to the processor’s TCK pin and
then fork back from the processor’s TCK pin and route back to ITP700FLEX connector’s FBO pin.
A 27.4- ± 1% pull-down to ground should be placed within ± 200 ps of the ITP700FLEX
connector pin.
Route the TDO signal from the processor to a 54.9- ± 1% pull-up resistor to VCCP that should be
placed close to ITP700FLEX connector’s TDO pin. Then insert a 22.6- ± 1% series resistor to
connect the 54.9- pull-up and “TDOITP” net (see Figure 41). Limit the L1 segment length of the
TDOITP net to be less than 1.0 inch.
The processor drives the BPM[4:0]# signals to the ITP700FLEX at a 100-MHz clock rate. Route the
BPM[4:0]# as a Zo=55 point-to-point transmission line connection between the processor and the
ITP700FLEX connector. Connect the ITP700FLEX connector’s BPM[3:0]# pins to processor’s
BPM[3:0]# pins. Connect the ITP700FLEX’s BPM[4]# signal to processor’s PRDY# pin. The
ITP700FLEX’s integrated far-end terminations as well as the processor’s AGTL+ integrated on-die
termination guarantee proper signal quality for the BPM[4:0]# signals. Due to the length of the
ITP700FLEX cable, the length L2 of the BPM[4:0]# signals on the motherboard should be limited to be
shorter than 6.0 inches. The BPM[4:0]# signals’ length L2 should be length matched to each other
within ± 50 ps. The BPM[4:0]# signal trace lengths are matched inside the processor package, thus
motherboard routing does not need to compensate for any processor package trace length mismatch.
Due to the processor’s AGTL+ on-die termination for BPM[3:0]# and PRDY#, there is no issue or
concern if the BPM[4:0]# pins of the ITP700FLEX connector are left floating when the ITP is not
being used and the ITP700FLEX cable is unplugged.
Route the ITP700FLEX connector’s BPM[5]# signal as a Zo = 55 point-to-point connection to
the processor’s PREQ# pin. Integrated on the ITP700FLEX BPM[5]# driver signal is a resistive
pull-up that guarantees proper signal quality at the processor’s PREQ# input pin. The processor has
an integrated, weak, on-die pull-up to VCCP for the PREQ# signal to guarantee a proper logic level
when the ITP700FLEX port connector is not plugged in. There is no need for any external
termination on the motherboard for the BPM[5]# = PREQ# signal. The maximum length of
BPM[5]#/PREQ# should not exceed 6.0 inches.
As explained in Sections 4.1.5 and 4.1.5.1, the RESET# signal forks (see Figure 26) out from the Intel
855PM MCH’s CPURST# pin and is routed to the processor and ITP700FLEX debug port. One branch
from the fork connects to the processor’s RESET# pin and the second branch connects to a 54.9 ± 1%
termination pull-up resistor to VCCP placed close to the ITP700FLEX debug port. A series 22.6 ± 1%
resistor is used to continue the path to the ITP700FLEX RESET# pin with the RESETITP# net in Figure
41. The length of the RESETITP# net (labeled as net L4) should be limited to be less than 0.5 inches
There is no need for pull-up termination on the processor side of the RESET# net due to presence of
AGTL+ on-die termination on the processor and the MCH.
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The ITP700FLEX debug port’s BCLKp/BCLKn inputs are driven with a 100-MHz differential clock
from the CK-408 clock chip. The CK-408 also feeds another two pairs of 100-MHz differential clocks
to the processor BCLK[1:0] and MCH BCLK[1:0] input pins. Common clock signal timing
requirements of the MCH and the processor requires matching of processor and MCH BCLK[1:0] nets
L6 and L7, respectively. To guarantee correct operation of ITP700FLEX, the BCLKp/BCLKn net L8
should be tuned to be within ± 50 ps to the sum of length L6 of the BCLK[1:0] lines and the additional
length L2 of the BPM#[4:0] signals.
i.e. L6 + L2 = L8 (within ± 50 ps)
The timing requirements for the BPM[5:0]#, RESET#, and BCLKp/BCLKn signals of the ITP700FLEX
debug port requires careful attention to their routing. Standard high frequency bus routing practices
should be observed.
1. Keep a minimum of 2:1 spacing in between these signals and to other signals.
2. Reference these signals to ground planes and avoid routing across power plane splits.
3. The number of routing layer transitions should be minimized. If layout constraints require a
routing layer transition, any such transition should be accompanied with ground stitching vias
placed within 100mils of the signal via with at least one ground via for every two signals making
a layer transition.
DBR# should be routed to the system reset logic (e.g. the SYSRST# signal of the ICH4-M)
and initiate the equivalent of a front panel reset commonly found in desktop systems. The 150to 240- pull-up resistor should be placed within 1 ns of the ITP700FLEX connector. Note
that the CPU should not be power cycled when DBR# is asserted.
DBA# is an optional system signal that can be used to indicate to the system that the ITP/TAP
port is being used. If not implemented, this signal can be left as no connect. If implemented, it
should be routed with a 150- to 240- pull-up resistor placed within 1ns of the
ITP700FLEX connector. See the ITP700 Debug Port Design Guide for more details on DBA#
usage.
The ITP700FLEX VTT and VTAP pins should be shorted together and connected to the VCCP
(1.05 V) plane with a 0.1-µF decoupling capacitor placed within 0.1 inch of the VTT pins.
Table 17 summarizes termination resistors values, placement, and voltages the ITP signals need to
connect to for proper operation for onboard ITP700FLEX debug port.
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Table 17. Recommended ITP700FLEX Signal Terminations
Signal
Termination Value
Termination Voltage
Termination/Decap Location
Notes
TDI
150
± 5%
VCCP (1.05 V)
Within ± 300 ps of the processor
TDI pin
5
TMS
39.2
± 1%
VCCP (1.05 V)
Within ± 200 ps of the ITP700FLEX
connector TMS pin
5
TRST#
510 – 680
GND
Anywhere between processor and
ITP700FLEX connector
5
TCK
27.4
GND
Within ± 200 ps of the ITP700
FLEX connector TCK pin
5
TDO
54.9 ± 1% pull-up and
22.6 ± 1% series
resistor
VCCP (1.05 V)
Within 1” of the ITP700FLEX
connector TDO pin
1, 5
± 5%
± 1%
BCLK(p/n)
2
FBO
Connect to TCK pin of
CPU
N/A
N/A
1
RESET#
54.9 ± 1% pull-up and
22.6 ± 1% series
resistor
VCCP (1.05 V)
Within 0.5” of the ITP700FLEX
connector RESET# pin
1
BPM[5:0]#
Not Required
DBA#
150-240
± 5%
VCC of target system
recovery circuit.
Within 1 ns of the ITP700FLEX
connector DBA# pin
DBR#
150-240
± 5%
VCC of target system
recovery circuit
Within 1 ns of the ITP700FLEX
connector DBR# pin
VTAP
Short to VCCP plane
VCCP (1.05 V)
VTT
Short to VCCP plane
VCCP (1.05 V)
3
4
Add 0.1-µF decap within 0.1 inch of
VTT pins of ITP700FLEX connector
NOTES:
1. See Figure 41.
2. Refer to Section 4.3.1.1.
3. All the needed terminations to guarantee proper signal quality are integrated inside the processor AGTL+ buffers
or inside the ITP700FLEX debug port. No need for any external components for the BPM[5:0]# signals.
4. Only required if DBA# is used with any target system circuitry. This signal may be left unconnected if unused.
5. In cases where a system is designed to utilize the ITP700FLEX debug port for debug purposes but the
ITP700FLEX connector may or may not be populated at all times although the signal routing and termination or
decoupling components are implemented, the component placement guidelines should adhere to the ones listed
in Table 17. However, for signals where the termination component placement guidelines for non-ITP700FLEX
supported systems (see Table 16) are more restrictive or conservative than the component placement guidelines
for the ITP700FLEX supported case, then the more conservative/restrictive guidelines should be followed.
4.3.1.2.
ITP Signal Routing Example
Figure 43 illustrates a recommended layout example for the ITP700FLEX signals. The ITP700FLEX
connector is placed on the primary side of the motherboard and results in a smooth, straight-forward
routing solution.
Note that the VCCP (1.05 V) power delivery continues from the processor socket cavity on the secondary
side of the motherboard through the pin field as shown on the right side of Figure 43. Three VCCP vias in
conjunction with three ground stitching vias allow a transition to the primary side to connect to the VTT
and VTAP pins of the ITP700FLEX connector and also a transition back to the secondary side of the
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motherboard. A small VCCP flood is created on the secondary side under the body of the ITP700FLEX
connector with a 0.1-µF decoupling capacitor. This also provides a convenient connection for the two
54.9- pull-ups for RESET# and TDO signals as well as the 39.2- pull-up for the TMS signal.
Notice the very short trace from the 22.6- series resistors for the RESET# and TDO signals to the
ITP700FLEX pins. See also Section 4.1.5.1 for more details of RESET# signal routing.
The 150- pull-up resistor for TDI is connected to the VCCP (1.05 V) flood on the secondary side close
to processor pin.
The ITP700FLEX TCK pin has a 27.4- pull-down to ground very close to the ITP700FLEX connector
and also routes to the processor’s TCK pin and loops back with no stub to the FBO pin of the
ITP700FLEX connector.
BCLKp/BCLKn are routed in this example on Layer 3. For more BCLKp/BCLKn routing details, refer
to Figure 28 in Section 4.1.6.
All other signals incorporate a straight forward routing methodology between the ITP700FLEX and
processor pins.
4.3.1.3.
ITP_CLK Routing to ITP700FLEX Connector
A layout example for ITP_CLK/ITP_CLK# routing to an ITP700FLEX connector is shown in Figure
42. The CK-408 clock chip is mounted on the primary side of the motherboard and the differential clock
pair also breaks out on the same side. The differential ITP clock pair routing requires the use of a pair of
33- ± 5% series resistors placed within 0.5 inches of the clock chip output pins followed by a pair of
49.9- ± 1% termination resistors to ground. The ITP_CLK/ITP_CLK# signals route as a differential
pair with a 4-mil trace width on 7-mil spacing from the junction of the 33- and 49.9- ± 5% resistors
across the internal Layer 6 through an open channel to the ITP700FLEX connector. Serpentining of the
ITP_CLK traces is also performed in order to meet the ± 50 ps length matching requirement between
ITP_CLK and the sum of length L6 of the BCLK[1:0] lines and the additional length L2 of the
BPM#[5:0] signals in Figure 41. The ITP_CLK pair routing then switches back to the primary side layer
through a via near the ITP700FLEX connector.
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Figure 42. ITP_CLK to ITP700FLEX Connector Layout Example
ITP700FLEX
Connector
PRIMARY SIDE
49.9Ω
33Ω
ITP_CLK
CK-408
LAYER 6
84
ITP_CLK
ITP_CLK#
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Figure 43. ITP700FLEX Signals Layout Example
Primary Side
Secondary Side
1.05v
150Ω
VCCA=1.8v
1.05v
4.3.1.4.
TDI
TMS
TRST#
TCK
TDO
FBO
1.05v
27.4Ω
BPM[5:0]#
VTT, VTAP
680Ω
DBR#
39.2Ω
0.1uF
22.6Ω
54.9Ω
54.9Ω 1.05v 22.6Ω
TDO
RESET#
ITP700FLEX Design Guidelines for Production Systems
For production systems that do not populate the onboard ITP700FLEX debug port connector, the
following guidelines should be followed to ensure that all necessary signals are terminated properly.
Table 16 summarizes all the signals that require termination when a system does not populate the
ITP700FLEX connector but still implements the routing for all the signals. This includes TDI, TMS,
TRST#, and TCK. Based on the recommended values in this table, the resistor tolerances for TMS and
TCK can be relaxed from ± 1% to ± 5% to reduce cost. Also, TDO can be left as a no connect, thus the
54.9 ± 1% pull-up and 22.6 ± 1% series resistors can be removed.
For the ITP700FLEX connector’s RESET# input signal, it is only possible to depopulate the 22.6 ±
1% series resistor. The 54.9 ± 1% pull-up resistor is required for termination purposes if the routing
for RESET# is not modified. RESET# would be a long, unterminated transmission line if the 54.9 ±
1% is not populated and could affect CPURST# signal quality and performance at the Intel 855PM
MCH and the processor. If the routing for RESET# is removed or disconnected at the output of the
MCH’s CPURST# pin, then it is possible to also remove the 54.9 ± 1% resistor.
The series 33- and 49.9- ± 1% parallel termination resistors on the ITP_CLK/ITP_CLK# differential
host clock inputs to the ITP700FLEX connector can also be depopulated for production systems. The
only requirement is that the BIOS should disable the third differential host clock pair routed from the
CK-408 clock chip to the ITP700FLEX connector.
Finally, the 150- to 240- pull-up resistor for the DBR# output signal from the ITP700FLEX
connector may or may not be depopulated depending on how it affects the system reset logic that it is
connected to. Thus, it is the responsibility of the system designer to determine whether termination for
DBR# is required or not for a given system implementation. The same is also true for DBA#, if
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implemented. It is the responsibility of the system designer to determine whether termination for DBA#
is required or not.
4.3.2.
Recommended ITP Interposer Debug Port Implementation
Intel is working with American Arium* to provide ITP interposer cards for use in debugging Intel
Pentium M and Intel Celeron M processor based systems as an alternative to the onboard ITP700FLEX
in cases where the onboard connector cannot be supported. The ITP interposer card is an additional
component that integrates a processor socket along with ITP700 connector on a single interposer card
that is compatible with the 478-pin Intel Pentium M processor / Intel Celeron M processor socket.
Table 16 summarizes all the signals that require termination for a system designed for use with the ITP
interposer. This includes TDI, TMS, TRST#, and TCK. Also, TDO can be left as a no connect.
DBR# should be routed to the system reset logic (e.g. the SYSRST# signal of the ICH4-M) and initiate
the equivalent of a front panel reset commonly found in desktop systems. The 150- to 240- pull-up
resistor should be placed within 1ns of the ITP connector. Note that the processor should not be power
cycled when DBR# is asserted.
DBA# is an optional system signal that can be used to indicate to the system that the ITP/TAP port is
being used. If not implemented, this signal can be left as no connect. If implemented, it should be routed
with a 150- to 240- pull-up resistor placed within 1 ns of the ITP connector. See the ITP700 Debug
Port Design Guide for more details on DBA# usage.
4.3.2.1.
ITP_CLK Routing to ITP Interposer
A layout example for ITP_CLK/ITP_CLK# routing to the processor socket for supporting an ITP
interposer is shown in Figure 44. The CK-408 clock chip is mounted on the primary side layer of the
motherboard and the differential clock pair also breaks out on the same side. The differential ITP clock
pair routing also requires the use of a pair of 33- ± 5% series resistors placed within 0.5 inches of the
clock chip output pins and followed by a pair of 49.9- ± 1% termination resistors to ground.
ITP_CLK/ITP_CLK# signals connect as a differential pair with 4-mil trace width on 7-mil spacing from
the junction of the 33- and the 49- resistors. The majority of the ITP_CLK differential serpentine
routing takes place on internal Layer 6 below the FSB address signal routing.
Completion of ITP_CLK routing on Layer 6 is not possible due to FSB routing on Layer 6. Therefore,
the ITP_CLK differential pair then is routed to the secondary side layer to complete routing to the
ITP_CLK (pin A16) and ITP_CLK# (pin A15) pins of the processor while matching the BCLK[1:0]
routing on the secondary side for a 507-mil length (see Figure 28 and description in Section 4.1.6).
Routing to the processor socket on the primary side layer is not possible because of the presence of the
VCCA 1.8-V plane flood along the A signal side row of the pin-map. ITP_CLK routing to the ITP
interposer should achieve the ± 50 ps length matching requirement of the BCLK[1:0] lines.
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Figure 44. ITP_CLK to CPU ITP Interposer Layout Example
A16, A15 pins
49.9Ω
33Ω
ITP_CLK
ITP_CLK#
CK-408
PRIMARY SIDE
4.3.2.2.
LAYER 6
SECONDARY
SIDE
ITP Interposer Design Guidelines for Production Systems
For production systems that do not use the ITP interposer, the following guidelines should be followed
to ensure that all necessary signals are terminated properly.
Table 16 summarizes all the signals that require termination when a system does not utilize the ITP
interposer. This includes TDI, TMS, TRST#, and TCK. TDO can be left as a no connect.
The series 33 and 49.9 ±1% parallel termination resistors on the ITP_CLK/ITP_CLK# differential
host clock inputs to the processor socket can also be depopulated for production systems. The only
requirement is that the BIOS should disable the third differential host clock pair routed from the CK-408
clock chip to the Intel Pentium M processor / Intel Celeron M processor socket.
Finally, the 150- to 240- pull-up resistor for the DBR# output signal from processor socket may or
may not be depopulated depending on how it affects the system reset logic that it is connected to. Thus,
it is the responsibility of the system designer to determine whether termination for DBR# is required or
not for a given system implementation. The same is also true for DBA#, if implemented. It is the
responsibility of the system designer to determine whether termination for DBA# is required or not.
4.3.3.
Logic Analyzer Interface (LAI)
Intel is working with Agilent* Corporation to provide logic analyzer interfaces (LAIs) for use in
debugging Intel Pentium M/Intel Celeron M processor-based systems. LAI vendors should be contacted
to get specific information about their logic analyzer interfaces. The following information is general in
nature. Specific information must be obtained from the logic analyzer vendor.
Due to the complexity of an Intel Pentium M/Intel Celeron M processor-based system, the LAI is critical
in providing the ability to probe and capture FSB signals. There are two sets of considerations to keep in
mind when designing an Intel Pentium M/Intel Celeron M processor-based system that can make use of
an LAI: mechanical and electrical.
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4.3.3.1.
Mechanical Considerations
The LAI is installed between the processor socket and the Intel Pentium M/Intel Celeron M processor.
The LAI pins plug into the socket, while the processor in the 478-pin package plugs into a socket on the
LAI. Cabling this part of the LAI egresses the system to allow an electrical connection between the
processor and a logic analyzer. The maximum volume occupied by the LAI, known as the keep-out
volume, as well as the cable egress restrictions, should be obtained from the logic analyzer vendor.
System designers must make sure that the keepout volume remains unobstructed inside the system. Note
that it is possible that the keepout volume reserved for the LAI may include space normally occupied by
the processor heat sink. If this is the case, the logic analyzer vendor will provide a cooling solution as
part of the LAI.
4.3.3.2.
Electrical Considerations
The LAI will also affect the electrical performance of the FSB. Therefore, it is critical to obtain
electrical load models from each of the logic analyzers to be able to run system level simulations to
prove that their tool will work in the system. Contact the logic analyzer vendor for electrical
specifications as load models for the LAI solution they provide.
4.4.
Intel Pentium M Processor / Intel Celeron M Processor
and Intel 855PM MCH FSB Signal Package Lengths
Table 18 lists the package trace lengths of the Intel Pentium M processor / Intel Celeron M processor
and the Intel 855PM MCH for the source synchronous data and address signals. All the signals within
the same group are routed to the same length as listed below with ± 0.1-mil accuracy. As a result of this
package trace length matching, no motherboard trace length compensation is needed for these signals.
Refer to Section 4.1.3 for further details. The processor and MCH package traces are routed as microstrip lines with a nominal characteristic impedance of 55 ± 15%.
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Table 18. Processor and MCH FSB Signal Package Trace Lengths
Signal Group
CPU Signal Name
Processor Package Trace
Length (mils)
MCH Signal Name
MCH Package
Trace Length (mils)
SOURCE SYNCHRONOUS – DATA & ADDRESS SIGNALS
D[15:0]#
722
HD[15:0]#
851
DINV[0]#
722
DBI[0]#
851
DSTBP[0]#
722
HDSTBP[0]#
851
DSTBN[0]#
722
HDSTBN[0]#
851
D[31:16]#
564
HD[31:16]#
958
DINV[1]#
564
DBI[1]#
958
DSTBP[1]#
564
HDSTBP[1]#
958
DSTBN[1]#
564
HDSTBN[1]#
958
D[47:32]#
661
HD[47:32]#
760
DINV[2]#
661
DBI[2]#
760
DSTBP[2]#
661
HDSTBP[2]#
760
DSTBN[2]#
661
HDSTBN[2]#
760
D[63:48]#
758
HD[63:48]#
709
DINV[3]#
758
DBI[3]#
709
DSTBP[3]#
758
HDSTBP[3]#
709
DSTBN[3]#
758
H DSTBN[3]#
709
REQ[4:0]#
616
HREQ[4:0]#
662
A[16:3]#
616
HA[16:3]#
662
ADSTB[0]#
616
HADSTB[0]#
662
A[31:17]#
773
HA[31:17]#
686
ADSTB[1]#
773
HADSTB[1]#
686
Data Group 1
Data Group 2
Data Group 3
Data Group 4
Address
Group 1
Address
Group 2
COMMON CLOCK SIGNALS
ADS#
454
ADS#
338
BNR#
506
BNR#
536
BPRI#
424
BPRI#
425
BR0#
336
BREQ0#
329
DBSY#
445
DBSY#
440
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Signal Group
CPU Signal Name
Processor Package Trace
Length (mils)
MCH Signal Name
MCH Package
Trace Length (mils)
DEFER#
349
DEFER#
544
DPWR#
506
DPWR#
365
DRDY#
529
DRDY#
627
HIT#
420
HIT#
533
HITM#
368
HITM#
611
LOCK#
499
HLOCK#
611
RS[0]#
576
RS[0]#
350
RS[1]#
524
RS[1]#
467
RS[2]#
451
RS[2]#
442
TRDY#
389
HTRDY#
494
RESET#
455
CPURST#
499
DIFFERENTIAL HOST CLOCKS
BCLK0
447
BCLK0
503
BCLK1
447
BCLK1
503
Host Clocks
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5.
Platform Power Requirements
5.1.
General Description
The Intel Pentium M processor supports Enhanced Intel® SpeedStep® technology, which enables realtime dynamic switching of the voltage and frequency between multiple performance modes. This occurs
by switching the bus ratios, core operating voltage, and core processor speeds without resetting the
system. With Enhanced Intel® SpeedStep® technology, there will be more than two modes of operation.
The processor will be able to operate in more than two voltage levels. Although this specification
addresses the highest processor core frequency and the lowest processor core frequency, there will be
other modes where the voltage command may be different than that of these two modes. The Intel
Celeron M processor does not support Enhanced Intel SpeedStep technology.
Terminology used to reference the names of the voltage rails are defined below.
VCC-CORE is the core rail of the processor
VCCP is the FSB rail of the processor and MCH. Also used for CPU signals of ICH4-M chipset and
CPU ITP700FLEX debug port if used
VCC-MCH is the core rail of the MCH
5.2.
Intel 855PM MCH Phase Lock Loop Power Delivery
Design Guidelines
5.2.1.
Intel 855PM MCH PLL Power Delivery
VCCGA and VCCHA are two pins on the Intel 855PM MCH that supply power to the PLL clock generators
on the MCH silicon. Since these PLLs are analog in nature, they require quiet power supplies for
minimum jitter. Jitter is detrimental to the system; it degrades external I/O timings as well as internal
core timings (i.e. maximum frequency). Traditionally these supply pins are low-pass filtered to prevent
any performance degradation. The MCH has an internal super filter for the 1.8-V analog supply. Thus,
the MCH does not require any external low-pass filtering for these power pins. However, one 10-nF
0603 form factor and one 10- F 1206 form factor decoupling capacitor should be placed as close as
possible to the VCCGA and VCCHA pins. It is acceptable to share one of the capacitors from each of
the listed types above for the two pins as long as a robust connection between the two pins is made. An
example of such a connection is shown below. The VCCGA and VCCHA pins will share the 1.8-V
power plane of the Hub Interface. However, it is advisable to connect the VCCGA and VCCHA pins
with a separate flood that will “fork out” from the bulk decoupling capacitors of the HI 1.8 V power
supplies and will route as a separate flood plane to the VCCGA and VCCHA pins without sharing the
power delivery pins of the MCH Hub Interface’s 1.8 V. To minimize inductance and resistance
parasitics, a flood with maximal width should be used along with 25-mil wide dog bone connections to
vias that connect BGA lands on the primary side.
In Figure 45, the recommended power delivery layout and decoupling for VCCGA and VCCHA is
shown. Notice on the left side of Figure 45 how the 1.8-V supply that powers the Hub Interface forks
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from the bulk decoupling capacitor via on the secondary side layer also routes through Layer 3 as a
separate branch to the 1.8-V flood that shorts the MCH VCCGA and VCCHA pins. The Hub Interface
1.8-V power delivery pin vias do not connect to the Layer 3 branch of the flood that feeds the VCCGA
and VSSGA pins. The flood continues to the processor’s VCCA[3:0] pins (1.8 V) on Layer 3, routing
between the common clock and source synchronous address signal routing corridor as explained in
Section 4.1.3.4, Figure 11, Figure 12, and Figure 13. The right side of Figure 45 illustrates that the
VCCGA pin is connected with a small flood on the secondary side to a 10-nF 0603 form factor capacitor
while the VCCHA pin with anther flood connects to a 1206 form factor 10-µF capacitor. Each of the
capacitors connect through a via to a robust, wide 1.8 V flood of Layer 3 shown on the left side of
Figure 45. The Layer 1 dog bone connection (not shown in Figure 45) should have a width of 25 mils
for each of the VCCGA and VCCHA pins.
Figure 45. Intel 855PM MCH 1.8 V VCCGA and VCCHA Recommended Power Delivery
LAYER 3
SECONDARY SIDE
VCCGA
VCCGA
VCCHA
DO NOT SHORT
VCCHA
To Pentium M
VCCA
HI 1.8V
5.2.2.
Intel 855PM MCH PLL Voltage Supply Power Sequencing
See Section 11.4.2 for more details on the platform power sequencing requirements for the 1.8-V supply
to the processor and Intel 855PM MCH’s PLLs.
5.3.
Processor Phase Lock Loop Power Delivery Design
Guidelines
5.3.1.
Processor PLL Power Delivery
VCCA[3:0] is a power source required by the PLL clock generators on the processor silicon. Since these
PLLs are analog in nature, they require quiet power supplies for minimum jitter. Jitter is detrimental to
the system: it degrades external I/O timings as well as internal core timings (i.e. maximum frequency).
Traditionally this supply is low-pass filtered to prevent any performance degradation. The processor has
an internal PLL super filter for the 1.8-V supply to the VCCA [3:0] pins that dispenses with the need for
any external low-pass filtering. However, one 0603 form factor 10-nF and one 1206 form factor 10- F
decoupling capacitor should be placed as close as possible to each of the four VCCA pins (i.e. a pair of
capacitors consisting of one 10-nF and one 10- F should be used for each VCCA pin). VCCA power
delivery should meet the 1.8 V ± 5% tolerance at the VCCA pins. As a result, to meet the current
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demand of the processor and future Intel Pentium M/Intel Celeron M family processor, it is strongly
recommended that the VCCA feed resistance from the 1.8 V power supply up to the VCCA shorting
scheme described below be less than 0.1 . Intel recommends that the main VCCA feed be connected to
the processor VCCA0 pin.
Figure 46 illustrates the recommended layout example of the VCCA[3:0] pins feed and decoupling. The
1.8-V flood on Layer 3 from Intel 855PM MCH is via’ed up to the primary side layer with a cluster of
five 1.8-V vias and two GND stitching vias as shown on the left and middle side of Figure 46. On the
primary layer side, a wide flood in a “U-Shape” shorts the four VCCA[3:0] pins of the processor. To
minimize resistance and inductance of the “U-Shaped” VCCA flood shorting the VCCA[3:0] pins, the
flood should be at least 100 mils wide and be spaced at least 25 mils from any switching signals. If
possible, a flood wider than the 100-mil minimum should be implemented and should reference a
ground plane only. Do not reference any switching signals or split planes. The recommended wide flood
on the primary side benefits from low inductance connections to the VCCA[3:0] pins due to the close
proximity of the Layer 2 solid ground plane 4 mils below the primary side 1.8-V flood. (Refer to the
stack-up description in Figure 2.) Decoupling capacitors for pin VCCA3 are placed on the primary side
in the vicinity of the GTLREF circuit (refer to Figure 30). No via is required to connect the VCCA3 side
of the capacitors to the VCCA3 pin. The groundside of the VCCA3 capacitors has a small ground flood
that is shared with the GTLREF circuit and connects to internal ground plane with two vias.
VCCA0 capacitors are also placed on the primary side. No via is needed on the VCCA0 side of the
capacitors that connect to the VCCA0 pin. A small ground flood on the primary side shorts the ground
side of the 1206 form factor 10- F VCCA0 decoupling capacitor via two GND stitching vias to
minimize interaction with FSB routing. The 0603 form factor 10-nF VCCA0 decoupling capacitor
connects to internal ground planes via a single GND stitching via.
VCCA1 decoupling capacitors are placed on the primary side on the bottom right corner of the
processor socket. No via is required to connect the VCCA1 side of the decoupling capacitors to the
VCCA1 pin. A small, ground plane connects the groundside of the 1206 form factor 10- F VCCA1
capacitors with a pair of vias to an internal ground plane. The 10- F decoupling capacitor connects to
internal ground planes via a single GND stitching via.
The decoupling capacitors for VCCA2 are placed on the primary side on the right side of the processor
socket. A small ground flood on the primary side is shared by the GND-side of the two required
decoupling capacitors for VCCA2. Both the 10-nF and 10- F capacitors are placed in a vertical
orientation on the primary side to avoid interaction with FSB routing and do not require vias on the
VCCA2 side to connect to the VCCA2 pin.
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Figure 46. Processor 1.8 V VCCA[3:0] Recommended Power Delivery and Decoupling
LAYER 3
GTLREF0
PRIMARY SIDE
VCCA2
VCCA3
VCCA0
VCCA1
1.8V from
1.8v
from
Intel 855PM
855PM
MCH
5.3.2.
Processor PLL Voltage Supply Power Sequencing
See Section 11.4.2 for more details on platform power sequencing requirements for the 1.8-V supply to
the processor and Intel 855PM MCH’s PLLs.
5.3.2.1.
Voltage Identification for Intel Pentium M/Intel Celeron M Processor
There are six voltage identification pins on the Intel Pentium M/Intel Celeron M processor. These
signals can be used to support automatic selection of VCC-CORE voltages. They are needed to cleanly
support voltage specification variations on current and future processors. VID[5:0] is defined in Table
19 below.
The VID[5:0] signals are 1.05-V CMOS level outputs. Intel recommends that 1:2 spacing and routing
with a trace impedance of 55 ± 15% be used. No external termination is required for VID[5:0]. To
guarantee signal quality, a point-to-point routing between the Intel processor and the VRM should be
used. Figure 47 illustrates a signal escape routing example in the vicinity of the processor package
outline. To allow for the coexistence of VCC-CORE and VCCP power delivery routing as well as FSB signal
routing, the VID[5:0] signals should utilize the remainder of the routing channels on Layer 3 ( for VID2
and VID0), Layer 6 (for VID4), and Layer 8 (for VID1, VID3, and VID5).
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Figure 47. Intel® Pentium® M Processor / Intel® Celeron® M Processor VID[5:0] Escape Routing
Layout Example
TO VRM
LAYER 3
VID2
VID0
VCC_CORE
LAYER 6
VCC_CORE
VID4
Secondary
Side
VCC_CORE
VID5
VID3
VID1
VCCP
VCCP
To
ToITPFLEX
ITPFLEX
& ICH4-M
& ICH4
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Table 19. VID vs. VCC-CORE Voltage
VID
96
VID
VCC-CORE
VCC-CORE
5
4
3
2
1
0
V
5
4
3
2
1
0
V
0
0
0
0
0
0
1.708
1
0
0
0
0
0
1.196
0
0
0
0
0
1
1.692
1
0
0
0
0
1
1.180
0
0
0
0
1
0
1.676
1
0
0
0
1
0
1.164
0
0
0
0
1
1
1.660
1
0
0
0
1
1
1.148
0
0
0
1
0
0
1.644
1
0
0
1
0
0
1.132
0
0
0
1
0
1
1.628
1
0
0
1
0
1
1.116
0
0
0
1
1
0
1.612
1
0
0
1
1
0
1.100
0
0
0
1
1
1
1.596
1
0
0
1
1
1
1.084
0
0
1
0
0
0
1.580
1
0
1
0
0
0
1.068
0
0
1
0
0
1
1.564
1
0
1
0
0
1
1.052
0
0
1
0
1
0
1.548
1
0
1
0
1
0
1.036
0
0
1
0
1
1
1.532
1
0
1
0
1
1
1.020
0
0
1
1
0
0
1.516
1
0
1
1
0
0
1.004
0
0
1
1
0
1
1.500
1
0
1
1
0
1
0.988
0
0
1
1
1
0
1.484
1
0
1
1
1
0
0.972
0
0
1
1
1
1
1.468
1
0
1
1
1
1
0.956
0
1
0
0
0
0
1.452
1
1
0
0
0
0
0.940
0
1
0
0
0
1
1.436
1
1
0
0
0
1
0.924
0
1
0
0
1
0
1.420
1
1
0
0
1
0
0.908
0
1
0
0
1
1
1.404
1
1
0
0
1
1
0.892
0
1
0
1
0
0
1.388
1
1
0
1
0
0
0.876
0
1
0
1
0
1
1.372
1
1
0
1
0
1
0.860
0
1
0
1
1
0
1.356
1
1
0
1
1
0
0.844
0
1
0
1
1
1
1.340
1
1
0
1
1
1
0.828
0
1
1
0
0
0
1.324
1
1
1
0
0
0
0.812
0
1
1
0
0
1
1.308
1
1
1
0
0
1
0.796
0
1
1
0
1
0
1.292
1
1
1
0
1
0
0.780
0
1
1
0
1
1
1.276
1
1
1
0
1
1
0.764
0
1
1
1
0
0
1.260
1
1
1
1
0
0
0.748
0
1
1
1
0
1
1.244
1
1
1
1
0
1
0.732
0
1
1
1
1
0
1.228
1
1
1
1
1
0
0.716
0
1
1
1
1
1
1.212
1
1
1
1
1
1
0.700
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5.3.2.2.
VCC-CORE Power Sequencing
There is only one enable pin, VR_ON, used to enable the outputs of the voltage regulator. When
VR_ON is low, all output voltage rails (VCC-CORE, VCCP, and VCC_MCH) are driven to a 0-V state. When
VR_ON is high, VCCP, VCC_MCH and VCC-CORE are commanded ramp up at the same time. Figure 48
illustrates the power on sequencing timing.
Figure 48. Power On Sequencing Timing Diagram
VID
t SFT_START_VCC
VR_ON
-12%
V BOOT
V VID
t BOOT
V
CC-CORE
CPU_UP
t BOOT-VID-TR
t CPU_UP
-12%
VCCP
Vccp_UP
t Vccp_UP
- 12%
VCC_MCH
MCH_PWRGD
t MCH-PWRGD
CLK_ENABLE#
See Note 1.
IMVP4_PWRGD
tCPU_PWRGD
See Note 1.
NOTES:
1. Desired, but not required feature of a processor and chipset regulator controller. If not implemented by the
controller, both the CLK_ENABLE# and the tCPU-PWRGD timer must be implemented by platform control logic.
2. Figure 48 depicts a number of signals that may or may not be platform visible.
See Section 11.4 for platform power sequencing details and timing requirements.
5.4.
VCCP Output Requirements
The VCCP output voltage rail provides power to the FSB rail for the Intel Pentium M/Intel Celeron M
processor, the Intel 855PM MCH, the 82801DBM ICH4-M, and ITP700FLEX debug port if it is used.
For the ICH4-M, this rail is known as VCPU_IO. The voltage regulator can be programmed via an external
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resistor network. See Figure 49. VREF is used to set the highest output voltage in conjunction with the
selection of R5 & R6 in the resistor network.
Figure 49. VCCP Block Diagram
Voltage
Regulator
V
CCP
* +/-0.1%
Tolerance
Recommended
V REF
R6 *
R5 *
Intel Pentium
M processor
Intel 855PM
MCH
Intel 82801DBM
ICH4M
ITPFLEX
5.5.
VCC-MCH Output Requirements
The VCC-MCH output rail provides power to the core of the Intel 855PM MCH. The nominal voltage of
VCC-MCH is 1.2 V. The voltage regulator can be programmed via an external resistor network. See Figure
50. VREF is used to set the highest output voltage in conjunction with the selection of R7 and R8 in the
resistor network..
Figure 50. VCC-MCH Block Diagram
Voltage
Regulator
VREF
5.6.
V CC_MCH
R7 *
Intel
855PM
MCH
* +/-0.1%
Tolerance
R8 *
Recommended
Thermal Power Dissipation
Power dissipation has traditionally been a thermal/mechanical challenge for mobile system designers.
The amount of current required from the processor power delivery circuit and the heat generated by
processors has increased as processor frequencies go up and the silicon process geometry shrinks. The
package of any integrated device can only dissipate so much heat into the surrounding environment. The
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temperature of a device, such as a processor power delivery circuit-switching transistor, is a balance of
heat being generated by the device and its ability to shed heat either through radiation into the
surrounding air or by conduction into the circuit board. Increased power will effectively raise the
temperature of the processor power delivery circuits. Switching transistor die temperatures can exceed
the recommended operating value if the heat cannot be removed from the package effectively.
As the current demands for higher frequency and performance processors increases, the amount of
power dissipated, i.e., heat generated, in the processor power delivery circuit has become of concern for
mobile system, thermal, and electrical design engineers. The high input voltage, low duty factor inherent
in mobile power supply designs leads to increasing power dissipation losses in the output stage of the
traditional buck regulator topology used in the mobile industry today.
These losses can be attributed to three main areas of the processor power delivery circuit. The switching
MOSFET dissipates a significant amount of power during switching of the top control MOSFET, power
dissipation resulting from drain to source resistance (RDS(ON) ) DC losses across the bottom synchronous
MOSFET, and the power dissipation generated through the magnetic core and windings of the main
power inductor.
There has been significant improvement in the switching MOSFET technology to lower gate charge of
the control MOSFET allowing them to switch faster thus reducing switching losses. Improvements in
lowering the RDS(ON) parametric of the synchronous MOSFET have resulted in reduced DC losses. The
Direct Current Resistance (DCR) of the power inductor has been reduced, as well, to lower the amount
of power dissipation in the circuit’s magnetic.
These technology improvements by themselves are not sufficient to effectively remove the heat
generated during the high current demand and tighter voltage regulation required by today’s mobile
processors. There are several mechanisms for effectively removing heat from the package of these
integrated devices. Some of the most common methods are listed below.
Attaching a heat spreader or heat pipe to the package with a low thermal co-efficient bonding
material
Adding and/or increasing the copper fill area attached to high current carrying leads
Adding or re-directing air flow to flow across the device
Utilize multiple devices in parallel, as allowed, to reduce package power dissipation
Utilizing newer/enhanced technology and devices to lower heat generation but with equal or better
performance.
For the mobile designer, these options are not always available or economically feasible. The most
effective method of thermal spreading and heat removal, from these devices, is to generate airflow
across the package AND add copper fill area to the current carrying leads of the package.
The processor power delivery topology can also be modified to improve the thermal spreading
characteristic of the circuit and dramatically reduce the power dissipation requirements of the switching
MOSFET and inductor. This topology referred to as multi-phase, provides an output stage of the
processor regulator consisting of several smaller buck inductor phases that are summed together at the
processor. Each phase can be designed to handle and source a much smaller current. This can reduce the
size, quantity, and rating of the components needed in the design. This can also decrease the cost and
PCB area needed for the total solution. The implementation options for this topology are discussed in
the next section.
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5.7.
Voltage Regulator Topology
In a single-phase topology, the duty cycle of the Control (top) MOSFET is roughly the ratio of the
output voltage and the input voltage. Due to the small ratio between VCC-CORE and VDC, the duty cycle of
the Control MOSFET is very small. The main power loss in the Control MOSFET is therefore due to the
transition or switching loss as it switches on and off. To minimize the transition loss in the Control
MOSFET, its transition time must be minimized. This is usually accomplished with the use of a smallsize MOSFET. Or similarly, the duty cycle of the Synchronous MOSFET is very large; hence, to
minimize the DC loss of the Synchronous MOSFET, its RDS-ON must be small. This is usually
accomplished with the use of a large-size MOSFET or several small-size MOSFETs connected in
parallel, but this solution usually leads to shoot-through current as it is quite difficult to minimize the
effect of the Gate-Glitch phenomenon in the Synchronous MOSFET due to CGD charge coupling effect.
It is, therefore, necessary to go to multi-phase topology. In a multi-phase topology, the output load
current is sourced from multiple sources or output stages. The term multi-phase implies that the phases
or stages are out of phase with respect to each other. For example, in a dual-phase topology, the stages
are exactly 180 output of phase.
Refer to Figure 51 for a block diagram for a dual-phase topology.
Figure 51. Voltage Regulator Multi-Phase Topology Example
VDC
R
CO1
e
Voltage
g
Regulator
IMVP-ul
at
CO2
o
r
5.8.
L
DRIVER
STAGE
RS
VCC
C BULK
VDC
DRIVER
STAGE
L
RS
Voltage Regulator Design Recommendations
When laying out the processor power delivery circuit using a traditional Buck Voltage Regulator on a
printed circuit board, the following checklist should be followed.
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Figure 52. Buck Voltage Regulator Example
V_DC
NMOS
DRIVER
Output Vcc
TG
CO
+
NMOS
RLoad
BG
SCHOTTKY
Voltage
Regulator
ControlCircuitry
5.8.1.
Feed back
High Current Path, Top MOSFET Turned ON
The dashed/arrow line in Figure 53 indicates the high current path when the top MOSFET is ON.
Current flows from the V_DC power source, through the top MOSFET (There may be more than one of
these.), through the inductor and sense resistor and finally through the processor, RLoad, to ground. The
components and current paths shown must be able to not only carry the high current through the
processor, but the power source and ground must also be adequate.
Figure 53. High Current Path With Top MOSFET Turned ON
V_DC
NMOS
DRIVER
Output Vcc
TG
BG
+
CO
NMOS
RLoad
SCHOTTKY
Voltage
Regulator
ControlCircuitry
5.8.2.
Feed back
High Current Paths During Abrupt Load Current Changes
During abrupt changes in the load current, the bulk and decoupling capacitors must supply current for
the brief period before the regulator circuit can respond. The dashed/arrow line in Figure 54 illustrates
this current path. Stray inductance and resistance become a major concern and if they are not
minimized, they can compromise the effectiveness of the capacitors. Bulk capacitors for Vcc should be
located at the highest current density points. These high-density points are located along the shortest
route between the processor core and the sense resistor. Using short, fat traces or planes can minimize
both stray inductance and resistance.
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Figure 54. High Current Path During Abrupt Load Current Changes
V_DC
NMOS
DRIVER
Output Vcc
TG
CO
+
NMOS
RLoad
BG
SCHOTTKY
Voltage
Regulator
Control
Circuitry
5.8.3.
Feed back
High Current Paths During Switching Dead Time
When the top MOSFET turns OFF and before the bottom MOSFET (again there may be more than one
of these.) is turned ON, The pattern of current flow changes. The inductor is no longer being supplied
current through the top MOSFET starts to collapse its magnetic field. The inductor literally becomes a
generator, at this point. The dashed/arrow line in Figure 55 shows the current path during the time that
both top and bottom MOSFETs are OFF. This is termed “Dead Time.” During Dead Time there is a
high current flow through the inductor, processor, ground, and the Schottky diode. The diode and its
traces must be laid out in such as to minimize both stray inductance and resistance with short, fat traces
or planes.
Figure 55. High Current Path with Top and Bottom MOSFETs Turned Off (Dead Time)
V_DC
NMOS
DRIVER
Output Vcc
TG
+
CO
NMOS
BG
RLoad
SCHOTTKY
Voltage
Regulator
Control
Circuitry
5.8.4.
Feed back
High Current Path with Bottom MOSFET(s) Turned ON
A few nanoseconds after the top MOSFET is turned OFF, the bottom MOSFET(s) is turned ON. The
high current path now switches from the Schottky diode to the bottom MOSFET(s), the current path
shown by the dashed/arrow line in Figure 56. Minimize stray inductance and resistance with short, fat
traces or planes.
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Figure 56. High Current Path With Bottom MOSFET(s) Turned ON
V_DC
NMOS
DRIVER
Output Vcc
TG
+
CO
NMOS
BG
RLoad
SCHOTTKY
Voltage
Regulator
Control
Circuitry
5.8.5.
Feed back
General Layout Recommendations
All the components in the high current paths dissipate some power, i.e., they get warm when current
runs through them. To minimize temperature rise and facilitate thermal spreading, large copper fill areas
connecting the high current components is imperative. For example, the MOSFET manufacturers
recommend that each MOSFET be mounted on one square inch of two-ounce copper. While this may
not be possible in the mobile environment, this recommendation serves to illustrate the importance of
thermal considerations in the Switching Regulator layout.
Bulk capacitors for Vcc need three vias per pad if vias are not shared. Clusters of bulk and bypass
capacitors may be clustered along the high current paths between the sense resistor and the
processor. Clusters may have copper fill areas between capacitors. This provides additional
opportunities for vias – do not stop at three.
Some controllers sense the load on Vcc by monitoring the voltage drop across the sense resistor
with a Kelvin connection. The two feedback traces do not handle a high current, but must be of
equal lengths to get an accurate load measurement. Connect the feedback signal traces as close as
possible to both ends of the sense resistor. While the feedback traces do not handle high current,
they are high impedance and susceptible to interference from electrical and magnet noise. Avoid
routing these traces near the power inductor and avoid routing through vias.
The sense resistor is to be placed as close to the inductor as possible, followed by the first two bulk
capacitors.
The lead frame in the power MOSFETs is used to dissipate heat. To do this each of the power
MOSFETs requires 1 square inch of copper.
Avoid ground loops as they pick up noise. Use star or single point grounding. The source of the
lower (Synchronous bottom MOSFET) is an ideal point where the input and output ground planes
can be connected.
Keep the inductor-switching node small by placing the output inductor, switching top MOSFET
and synchronous Bottom MOSFETs close together on the same copper fill.
The MOSFET enable/gate traces to the Driver must be as short (less than 1 inch), straight, and wide
as possible (20 to 25 mils). Ideally, the driver has to be placed right next to the MOSFETs.
Circuits using multiple top or bottom MOSFETs need to have the gate traces serpentined so the all
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the traces going to the top MOSFETs Gates and most especially the bottom MOSFETs gates are the
same length.
Use the bulk capacitors and use multiple layer traces with heavy copper to keep the parasitic
resistance low. Use a minimum of three vias per connection on each bulk capacitor.
Place the top MOSFET drains as close to the VDC-input capacitors as possible.
The sense resistor has to be wide enough to carry the full load current. A minimum of 1 via per
Amp to the Vcc plane should be used. Use more if space permits.
Use solid 2-oz. copper fill under Drain and Source connections of the Top and Bottom MOSFETs.
The voltage regulator is usually left to the last moment. Often the allocated area is too small, a
narrow strip and the location poor. These factors combine so that the design flow, described above
usually cannot be followed.
General Rule: Copper Fill is Good. Fill the PCB with metal. There should be no large areas of the
board without metal. Widen the Grounds, Vcc and other power rails to fill any blank spots. Large
metal fill areas allow the voltage regulator to improve its heat radiation thus run cooler. Large
copper fill areas have other benefits too, including reducing stray resistance and inductance,
capturing and dissipating RF energy by allowing eddy currents to flow.
5.9.
Processor Decoupling Recommendations
Intel recommends proper design and layout of the system board bulk and high frequency decoupling
capacitor solution to meet the transient tolerance at the processor package balls. To meet the transient
response of the processor, it is necessary to properly place bulk and high frequency capacitors close to
the processor power and ground pins.
5.9.1.
Transient Response
The inductance of the motherboard power planes slows the voltage regulator’s ability to respond quickly
to a current transient. Decoupling a power plane can be partitioned into several independent parts. The
closer to the load the capacitor is placed, the more stray inductance is bypassed. By bypassing the
inductance of leads, power planes, etc., less capacitance is required. However, areas closer to the load
have less room for capacitor placement and therefore, tradeoffs must be made.
The processor causes very large switching transients. These sharp surges of current occur at the
transition between low power states and the normal operating states. The system designer must provide
adequate high frequency decoupling to manage the highest frequency components of the current
transients. Larger bulk storage capacitors supply current during longer lasting changes in current
demand.
All of this power bypassing is required due to the relatively slow speed at which a DC-to-DC converter
can respond. A typical voltage converter has a reaction time on the order of 1 to 100 s while the
processor’s current steps can be at shorter than 1 ns. High Frequency decoupling is typically done with
ceramic capacitors with a very low ESR. Because of their low ESR, these capacitors can act very
quickly to supply current at the beginning of a transient event. However, because the ceramic capacitors
are small, i.e. they can only store a small amount of charge, thus Bulk capacitors are needed too. Bulk
capacitors are typically polarized with high capacitance values and unfortunately higher ESLs and
ESRs. The higher ESL and ESR of the Bulk capacitor limit how quickly it can respond to a transient
event. The Bulk and high frequency capacitors working together can supply the charge needed to stay
in regulator before the regulator can react during a transient.
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A load change transient occurs when coming out of or entering a low power state. These are not only
quick changes in current demand, but also long lasting average current requirements. This occurs when
the processor enters different power modes by stopping and starting it’s internal clock. The processor
current requirements can change by as much as 60% of the maximum current very quickly.
The estimated Intel® Pentium® M Processor / Intel® Celeron® M Processor worst-case current
consumption change waveform is illustrated in Figure 57. This figure illustrates the expected waveform
seen at the die bumps of the CPU. Due to the presence of decoupling capacitors, it is expected that the
ramp rates of the current would slow down as seen by the motherboard’s high frequency and bulk
decoupling capacitors.
In Figure 57, worst-case leakage current is estimated to be 6.4 A. When the clock starts to toggle,
current consumption in one clock may change instantaneously, up to 60% of the estimated dynamic
current consumption of 18.6 A; thus, reaching a current of 17.56 A. After that initial step, the current
may ramp continually within 9 clocks; thus, reaching an estimated ICCMAX of 25 A. It should be noted
that current consumption of Intel Pentium M processor and Intel Celeron products may be lower than
what is shown in Figure 57. However, to guarantee the suitability of the motherboard and VRM design
for future, higher frequency products the VCC-CORE design should be able to meet the current
requirements of Figure 57.
Figure 57. Estimated Processor Current Consumption Change During STPCLK Exit
Icc[A]
9CLKs
ICCMAX = 25A
17.56A
IDYNMAX=18.6A
0.6*IDYNMAX=11.16A
ILKGMAX = 6.4A
1CLK
5.9.2.
t
High Frequency, Mid Frequency, and Bulk Decoupling
System motherboards should include high and mid frequency and bulk decoupling capacitors as close to
the socket power and ground pins as possible. Decoupling should be arranged such that the lowest ESL
devices (0612 reverse geometry type, if used for some of the recommended options below) are closest to
the processor power pins followed by the 1206 devices (if used), and finally, bulk electrolytics (organic
covered tantalum or aluminum covered capacitors). System motherboards should include bulkdecoupling capacitors as close to the processor socket power and ground pins as possible. The layout
example shown in Section 5.9.3 should be followed closely. Table 20 lists the recommended decoupling
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solutions for VCC-CORE, while Table 21 and Table 22 list the recommended decoupling solutions for the
VCCP and VCC_MCH supply rails, respectively. Also, see decoupling solutions for the VCC-CORE (section
5.9.3), VCCP (section 5.9.4) , and VCC_MCH (section 5.9.5) supply rails in the design guide. .
5.9.3.
Processor Core Voltage Plane and Decoupling
Due to the high current (up to 25 A) requirements of the processor core voltage, the VCC-CORE is fed from
the VRM by means of multiple power planes that provide both low resistance and low inductance paths
between the voltage regulator, decoupling capacitors, and processor VCC-CORE pins. To meet the VCC-CORE
transient tolerance specifications for the worst-case stimulus shown in Figure 57, the maximum
Equivalent Series Resistance (ESR) of the decoupling solution should be equal to or less than 3 m .
Figure 2 (see Section 3.1) shows an example of a motherboard power plane stack-up that allows for both
robust, high frequency signals routing and robust VCC-CORE power delivery.
The processor pin-map is shown in Figure 58 for reference in the discussion below. Note the highlighted
VCC-CORE power delivery corridor pins concentrated on the north side of the pin-map that contains fortynine VCC-CORE/GND pin pairs while the south side of the socket contains only 24 VCC-CORE/GND pin
pairs. Since access to the 24 south side pin pairs is blocked by the legacy signals, the only option
available for providing robust core power delivery to the processor is by placing the VRM and most of
the decoupling capacitors to the north of the core power delivery corridor (found on the north side of the
forty-nine VCC-CORE/GND pin pairs). It is advised to not feed the VR from any other side other than this
VCC-CORE corridor on the north side of the processor socket. Due to the high current demand, all the VCCCORE and ground vias of the processor pin-map should have vias that are connected to both internal and
external power planes. Sharing of vias between several VCC-CORE pins or ground pins is not allowed.
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Figure 58. Intel Pentium M Processor and Intel Celeron M ProcessorSocket Core Power Delivery
Corridor
VR Feed
49 VCC/GND
Pairs
24 VCC/GND
Pairs
A conceptual diagram of this VCC-CORE power delivery scheme is shown in Figure 59.
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Figure 59. Processor Core Power Delivery and Decoupling Concept
South/Legacy Side
Intel Pentium M Processor
Pentium
M Silicon
Die
Silicon
Die
North Side
VR
FEED
Rsense
PKG
SKT
VSS
L1 PS
L2 GND
L3 Sig
L4 GND
L5 PWR
L6 Sig
L7 GND
L8 SS
Signals
9
3
VCC-CORE
35x10uF
0805
9
+
8
+
-
6
4x220uF
SP Cap
In this example, bulk-decoupling 220- F SP capacitors (according to VCC-CORE recommended
decoupling guidelines) are placed on the north side of the secondary side layer in the processor VCC-CORE
power delivery corridor. Notice the VRM feed point (sense resistor connection) is on the positive
terminal side of the 220- F SP capacitors. Both VCC-CORE and ground vias are used on both sides of the
SP capacitors’ positive terminal side in order to reduce the inductance of the capacitor connection as
illustrated by the current flow loop area in Figure 59. If the VR feed is on the negative side of the SP
capacitors then both VCC-CORE and GND stitching vias will be needed on both the positive and negative
terminals of the capacitor to reduce the effective inductance of the capacitor.
Layers 1 (primary side layer), 3, 5, 6, and (secondary side layer) 8 are used for VCC-CORE current feeding
while referencing Layers 2, 4, and 7 (ground planes) with a small dielectric separation (see Figure 2 in
Section 3.1). These layers are solid ground planes in the areas under the processor package outline and
where the decoupling capacitors are placed. This results in a reduction in effective loop inductance. For
the recommended layout examples shown in Figure 59, Figure 60, Figure 61, and Figure 62, a low
inductance value of ~41 pH is achieved. Bulk decoupling capacitors respond too slowly to handle the
fast current transients of the processor. For this reason, 0805 mid frequency decoupling capacitors are
added on the primary and secondary side. Some are placed under the package outline of the processor
while the rest are placed in the periphery of the processor along the AF signal row of the pin-map where
a majority of the VCC-CORE power pins are found. A 4-mil power plane separation between the secondary
side power plane flood and Layer 7 ground while using the 0805 capacitors significantly reduces the
inductance of these capacitors. Results from a 3D field solver simulation suggest that an ESL of 600-pH
per capacitor can be used to help achieve the specific layout style described above. The ESL of the 0805
capacitors is a very critical parameter, thus the layout style shown in the recommendation below should
be closely followed. To stress the importance of 0805 capacitors that result in an ESL of 600 pH, it can
be compared to ~1.2 nH ESL for 1206 form factor capacitors. Please note that the 0805 capacitors have
VCC-CORE and ground vias on both negative and positive terminals similar to the 220- F SP capacitors in
order to achieve a low inductance connection.
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The motivation for concentrating the majority of the 0805 mid/high frequency decoupling capacitors and
all of the SP-type bulk decoupling capacitors on the secondary side layer is to take advantage of the VCCCORE corridor that establishes a robust connection from the VRM feed to the decoupling capacitors. On
the primary side, the dog bone via connections for the VCC-CORE pins and ground pins effectively
separate the VCC-CORE plane flood into multiple, relatively narrow strips separated by alternating Vss
dogbones. These narrow floods that feed the inner VCC-CORE pins of the processor are non-ideal and for
this reason, robust connections to capacitors are performed on the secondary side. Only three of the midfrequency decoupling capacitors need to be placed on the primary side.
Table 20 lists the decoupling solutions recommended by Intel for the processor’s VCC-CORE voltage rail.
The solution offers the benefits of robust electrical performance, comparable efficiency, minimal cost,
minimal motherboard surface area requirements, and lowest acoustic noise. It is a polymer-covered
aluminum and ceramic-decoupling capacitor based solution that implements 4 polymer covered
aluminum (SP type) capacitors that have a low ESR of 12 m each. It also uses 35 x 10 µF 0805 MLCC
mid frequency decoupling capacitors. Substitution of the 0805 capacitors with 1206 or other capacitors
with higher inductance is not allowed.
Table 20. VCC-CORE Decoupling Guidelines1
Description
Cap (µF)
Low Frequency Decoupling (Polymer Covered Aluminum
– SP Cap, AO Cap
4 x 220 µF
12 m
(max) / 4
2.5 nH / 4
Mid Frequency Decoupling (0805 MLCC, >= X6R)
35 x 10 µF
5m
(typ) / 35
0.6 nH / 35
ESR (m
ESL (nH)
NOTES:
2
1. VCC-CORE decoupling guidelines are recommended to be used with small footprint (100 mm or less) 0.36 H ± 20%
inductors.
An example layout implementation of the recommended VCC-CORE decoupling guidelines is illustrated
in Figure 60, Figure 61, and Figure 62 below. Figure 60 and Figure 61 show how the four, low
frequency SP decoupling capacitors are placed on the secondary side and connected to the AF signal
row of the processor pins with a solid VCC-CORE flood area along with eight of the mid frequency 0805
ceramic decoupling capacitors that are in between. To minimize the inductance of the SP capacitor
connection for the layout style shown, the sense resistors’ VRM feed is on the positive terminal side of
the SP capacitors. In this case each of the SP capacitors are connected to two pairs of VCC-CORE/GND
vias on the positive terminal. See Figure 61 for more details. If the VRM sense resistors connect from
the negative side of the SP capacitors, then two pairs of VCC-CORE/GND vias will be needed on both
positive and negative terminals of the SP capacitors.
Thirty-two, 10-µF, 0805 capacitors are placed on the secondary side (Layer 8) while the remaining three
are placed on the primary side (Layer 1). Six of the 10-µF capacitors are placed outside the socket
outline with a 90-mil (or closer) pitch (see Figure 61) and are divided evenly on either side for the four,
220-µF bulk capacitors (three to the left and three to the right of the SP capacitors). Each of these six
0805 capacitors have a pair of VCC-CORE and GND stitching vias next to both positive and negative
terminals of the capacitors. The stitching vias connect to the internal ground and VCC-CORE planes,
respectively.
The eight, 10-µF, 0805 capacitors (see Figure 61) that are located in between the SP capacitors and the
processor VCC-CORE “north corridor” pins also have a pair of VCC-CORE and GND stitching vias on both
sides of their terminals. The negative terminals share VCC-CORE and GND stitching via connections with
the six 0805 ceramic and SP capacitors mentioned above. The positive terminal VCC-CORE and GND
stitching connections are shared with the “north corridor” and ground pins of the AF signal row of the
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processor socket. To allow good current flow from the SP capacitors to the north side of the VCC-CORE
corridor pins, Intel recommends that these eight, 10- F 0805 capacitors be spaced 100 mils apart from
each other even if the motherboard design rules allow tighter spacing. The 100-mil horizontal spacing
allows some VCC-CORE flood in between the capacitor ground pads (as illustrated in Figure 61) as well as
additional connections to internal Layers 3, 5, and 6 as illustrated in Figure 62. An additional nine, 10µF, 0805 capacitors are placed along the Y signal row of the processor pins on the secondary side below
the VCC-CORE “north corridor” pins under the shadow of the socket cavity. These nine capacitors are
spaced 90 mils apart. Each of these nine 0805 capacitors have a pair of VCC-CORE and GND stitching vias
next to both their positive and negative terminals. The stitching vias connect to the internal ground and
VCC-CORE planes respectively. The positive terminal VCC-CORE and GND stitching vias are shared with the
AA signal row of the processor’s VCC-CORE and ground pins. A wide VCC-CORE power delivery corridor
flood on the secondary side of the motherboard connects the 0805 ceramic and SP capacitors that are
placed to the north of the processor socket and the nine capacitors that are placed under the shadow of
the socket cavity on the secondary side. The flood is as wide as the whole AF signal row and should
connect to all the VCC-CORE pins in signal rows Y, W, V, and U as illustrated in Figure 61.
The remaining nine (out of thirty-two) 10- F, 0805 (see Figure 60) capacitors are on the secondary side
are used to decouple the remainder of the twenty-four VCC-CORE/GND pin pairs on the south side of the
processor socket. These capacitors are placed along signal row G of the processor pins with a 90-mil (or
smaller) pitch. Each of the nine capacitors has a pair of VCC-CORE and GND stitching vias on both sides
of their terminals. Five out of nine capacitors share positive terminals with VCC-CORE and GND stitching
via connections with signal row F’s VCC-CORE and GND pins. The remaining four capacitors are placed
next to the VCCP pins of signal row F and have their own VCC-CORE vias but do share GND stitching vias.
As shown on the secondary side of Figure 60, a wide VCC-CORE flood connects the positive terminal of
these nine capacitors to all twenty-four VCC-CORE pins of the processor pin-map on the south side
including the VCC-CORE pins of signal rows K, J, H, and G. The reason for interruption of the VCC-CORE
flood on the secondary side between the north and south sides is to allow the VCCP corridor connection
between the DATA and ADDR sides of the processor socket.
The primary side view in Figure 60 depicts two wide VCC-CORE floods that connect from the VCC-CORE
stitching vias of the nine capacitors next to their negative terminal to the VCC-CORE pins of the two
clusters of the twenty-four VCC-CORE pins in rows K, J, H, G, F, E, and D of the processor pin-map. Note
the specific arrangement of the vias for the VCC-CORE dog bones to allow connection of all VCC-CORE BGA
balls in this cluster of twenty-four pins to the VCC-CORE flood shapes on the primary.
As described above in Figure 60, the VCC-CORE floods are isolated between the north and south sides of
the VCC-CORE pins of the processor socket on both the primary and secondary sides. The reason for the
discontinuity of the VCC-CORE floods on the primary and secondary sides is to facilitate VCCP power
delivery. Consequently, this allows the VCCP corridor connections between the DATA and ADDR sides
of the processor socket on the secondary side and the VCCP flood for all DATA, ADDR, and Legacy side
VCCP pins on the primary side (see Figure 60). In reality, the north and south sides of the VCC-CORE floods
are bridged by means of VCC-CORE planes in Layers 3, 5, and 6 as illustrated in Figure 62. Layers 3, 5,
and 6 connect the VCC-CORE stitching vias next to the negative terminals of the nine capacitors on the
north side with the VCC-CORE stitching vias next to the negative terminals of the nine capacitors on the
south side. Layers 3, 5, and 6 VCC-CORE corridors utilize the fact that there are no FSB signals routed
under the shadow of the processor socket cavity. All the VCC-CORE pins of the processor pin-map should
connect to the internal VCC-CORE planes of Layers 3, 5, and 6. Special attention should be give to not
route any of the FSB or any other signal in a way that would block VCC-CORE connections to all the VCCCORE power pins of the processor socket in Layers 3, 5, and 6. Figure 62 also shows how the VCC-CORE
planes on Layers 3, 5, and 6 make an uninterrupted connection all the way from the SP capacitors and
sense resistors in the north side of the VCC-CORE corridor up to the south side of the twenty-four VCC-CORE
pins of the processor socket. This continuous connection is imperative on all three internal layers since
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neither the primary nor the secondary side VCC-CORE floods make one continuous, robust connection
from “north to south.”
The remaining three, 10-µF, 0805 capacitors are placed on the primary side immediately above the
shadow of the three 0805 capacitors on the secondary side and are placed at the same pitch (90 mils) as
shown in Figure 60 and Figure 61. Two are on the side closest to the signal column 24 and 25 of the
processor pins while one is on the side closest to signal column 2. The area in between these three
capacitors can be efficiently used for VRM sense resistor connections as illustrated in the primary side
zoom in view in Figure 61.
Special care should be taken to provide a robust connection on the VCC-CORE floods on the primary side
from the sense resistors to the VCC-CORE corridor pins on the north side of the processor socket. This
robust connection is needed due to the presence of the GND dog bones on the primary side. The specific
arrangement of VCC-CORE and GND vias as shown in Figure 61 should be closely followed to provide a
robust connection to the VCC-CORE floods for ALL VCC-CORE BGA balls and vias on the primary side in
the AF, AE, AD, AC, AB, AA, Y, W, V, and U signal rows of the processor socket connecting all the
way up to VCC-CORE stitching vias next to negative terminals of the nine 0805 capacitors placed under the
socket cavity shadow.
Figure 63 shows a magnified view of the recommended layout for the SP capacitor connections to
minimize their inductance on the secondary side (Layer 8) of the motherboard. The VCC-CORE pin side of
the capacitor has two VCC-CORE vias placed 82 mils above the VCC-CORE pad of the SP capacitor within the
shadow of the SP capacitor. These two VCC-CORE vias are paired with two GND vias with a 50-mil offset
to reduce the inductance of the connection between the capacitor and the plane. An additional pair of
GND vias are placed 82 mils below the ground pad of the SP capacitor (also under the shadow of the SP
capacitor body) to allow efficient stitching of ground planes on Layers 1, 2, 4, 7, and 8 in this area.
Outside the shadow of the SP capacitors, the VCC-CORE/GND via pairs of the SP capacitors are shared
with the VCC-CORE/GND via pairs of the 0805 capacitors. The placement of additional vias is not advised
since this will result in excessive perforation of the internal power planes due to the antipad voids. The
pitch between the SP caps is 220 mils (or closer).
The layout concepts described in Figure 58 through Figure 63 result in an estimated VCC-CORE effective
resistance of 0.58 m and an effective inductance of ~41 pH. Despite the use of multiple power planes,
this is still significant compared to the 3-m load line target resistance and compared to the 17.1 pH
(600 pH / 35) inductance of the thirty-five 0805 decoupling capacitors. If alternative layout solutions
are used, they should be implemented with a level of robustness greater than or equal to that in the
example above. In terms of robustness, this refers to creating a low resistance and inductance connection
between the bulk and mid frequency capacitors and the processor pins.
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Figure 60. VCC-CORE Power Delivery and Decoupling Example – (Primary and Secondary Side
Layers)
Primary Side
Sense Resistors
VR Feed
2
4x220uF SP Cap
Secondary Side
3
1
-
-
-
-
+
+
+
+
+
+
+
+
3
8x10uFx0805
VCC_CORE
VCCP
VCC_CORE
VCCP
VCCP
To
855PM
To
MCH
855PM
9x10uFx0805
VCCP
9x10uFx0805
1.8v
VCCA
To 855PM
1.8v
VCCP
To ITP
L1
L2
L3
L4
L5
L6
L7
L8
PS
GND
Sig
GND
PWR
Sig
GND
SS
Cross
Section
View
+
+
-
Figure 61. Processor Core Power Delivery “North Corridor” Zoom In View
4x220uF SP Cap
Primary Side Sense Resistors
VR feed
Secondary Side
+
90mil
90mil
+
100mil
90mil
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Figure 62. VCC-CORE Power Delivery and Decoupling Example (Layers 3, 5, and 6)
VR Feed
LAYER 3
LAYER 5
VCC-CORE
LAYER 6
VCC-CORE
DATA
VCC-CORE
DATA
GND Ref for
Layer 6
ADDRESS
L1 PS
L2 GND
L3 Sig
L4 GND
L5 PWR
L6 Sig
L7 GND
L8 SS
ADDRESS
Cross
Sectional
View
+
+
-
Figure 63. Recommended SP Cap Via Connection Layout (Secondary Side Layer)
GND
-
50 mils
82 mils
50 mils
+
220 mils
82 mils
+
VCC-CORE
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5.9.4.
Intel Pentium M Processor / Intel Celeron M Processor and
Intel 855PM MCH VCCP Voltage Plane and Decoupling
The 400-MHz high frequency operation of the Intel Pentium M/Intel Celeron M and Intel 855PM
MCH’s FSB requires careful attention to the design of the power delivery for VCCP (1.05 V) to the
processor and MCH. Table 21 summarizes the VCCP (1.05 V) voltage rail decoupling requirements. Two
150-µF POSCAPs with an ESR of 36 m (typ) should be used for bulk decoupling. One capacitor
should be placed next to the processor socket and one capacitor in close proximity to the MCH package.
The current layout example recommends the placement of each POSCAP on the secondary side of the
motherboard to minimize inductance. In addition, ten 0.1-µF X7R capacitors in a 0603 form factor
should be placed on the secondary side of the motherboard under the processor socket cavity next to the
VCCP pins of the processor. Five capacitors should be spread out near the Data signal side and five
capacitors near the Address signal side of the processor socket’s pin-map. Eight more 0.1-µF X7R
capacitors in a 0603 form factor should be placed on the secondary side of the motherboard next to the
VCCP pins of the MCH. The processor and MCH VCCP pins should be shorted with a wide, VCCP plane
preferably on the secondary side such that it will extend across the whole “shadow” of the FSB signals
routed between the processor and MCH. The 1.05-V, VR feed point into the VCCP plane should be
roughly in between the processor and MCH.
Table 21. VCCP Decoupling Guidelines
Description
Cap (µF)
ESR
(m
ESL (nH)
Notes
Low Frequency Decoupling (Polymer Covered Tantalum –
POSCAP, Neocap, KO Cap)
2 x 150 µF
36 m
(typ) / 2
2.5 nH / 2
1
High Frequency Decoupling (0603 MLCC, >= X7R) Place
next to the processor
10 x 0.1 µF
16 m
(typ) / 10
0.6 nH / 10
High Frequency Decoupling (0603 MLCC, >= X7R) Place
next to the Intel 855PM MCH
8 x 0.1 µF
16 m
(typ) / 8
0.6 nH / 8
NOTES:
1. Place one capacitor close to processor and one capacitor close to the Intel 855PM MCH.
5.9.4.1.
Processor VCCP Voltage Plane and Decoupling
Figure 64 illustrates a conceptual cross sectional view of the recommended processor VCCP power
delivery layout. Due to the presence of the Layer 7 GND plane that is 4 mils above Layer 8 (see Figure
2), the secondary side layer (Layer 8) VCCP plane creates a low inductance short between the 0603 form
factor 0.1-µF capacitors and the 150-µF, POSCAP capacitor. At the same time, the VCCP plane on the
secondary side efficiently connects the capacitors to the processor VCCP pin vias. Ten, 0603 capacitors
are placed on the secondary side under the socket cavity shadow while the 150- F, POSCAP capacitor
is placed to the processor socket shadow close to the DATA side pins of the secondary side. Figure 65
shows a conceptual cross sectional view (left side of Figure 65) of the VCCP power delivery and how it
translates into an actual layout on the primary and secondary sides of the motherboard as shown on the
right side of Figure 65. The secondary side of Figure 65 utilizes a wide VCCP plane coming from the
MCH that shorts the VCCP pins of the DATA and ADDR side of the processor pin-map with the ten,
0603 form factor 0.1-µF decoupling capacitors that are placed on the secondary side in the shadow of
the processor socket cavity. These capacitors provide decoupling for the VCCP pins of the processor.
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Placement and layout of the ten, 0.1-µF capacitors should be strictly adhered to in order to minimize the
effective loop inductance of these capacitors. All the capacitors should be placed within 45 mils (centerto-center) of the VCCP pin rows. Ground vias for the 0.1-µF capacitors should also be placed within 45
mils of the capacitor pads and shorted with a 25-mil wide trace to the ground via.
In Figure 65, the secondary side shows one of the 150- F POSCAPs being placed next to the processor
socket close to the DATA pins. Notice that the ground pin connection of the POSCAP is extended
towards the VCCP pad of the capacitor with two ground vias placed under the body of the POSCAP. This
is done in order to minimize the inductance of the POSCAP connection by minimizing the loop area of
current flow.
Figure 65 also shows that a connection on the secondary side to the Legacy side VCCP pins of the
processor pin-map is not possible because it is blocked by the secondary side VCC-CORE flood that
connects the south side 0805 capacitors with the twenty-four VCC-CORE pins on the south side of the
processor pin-map (see secondary side of Figure 60 in Section 5.9.3). Thus, the primary side of Figure
65 illustrates a VCCP flood shape that shorts the DATA, ADDR, and Legacy VCCP pins of the processor
pin-map. The very specific arrangement of the VCCP/GND vias illustrated on the primary side of Figure
65 should be strictly followed to guarantee that each VCCP BGA ball of the processor pin-map connects
to the VCCP shape flood on the primary side. To guarantee robust connection to the ground balls around
the VCCP pins, 25-mil wide dog bones should be used while the VCCP BGA balls of the processor socket
are advised to use the wide VCCP flood in between the Vss dog bones as illustrated on the primary side of
Figure 65.
A VCCP flood “channel” should pass through the processor pin field on the bottom right side of the
processor socket to continue the VCCP feed to the ITP700FLEX debug port. A VCCP flood “channel” to
the ICH4-M is provided from the main VCCP flood plane of the MCH and circumvents the 1.5-V and
1.8-V plane floods to the MCH by routing around the AGP bus signal quadrant (not shown in figures).
Refer to Figure 65 for more details.
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Figure 64. Processor VCCP Power Delivery and Decoupling Concept
South/Legacy Side
VCCP = 1.05v
Short DATA, ADDR &
Legacy Sides
Intel Pentium M
processorM(Silicon
Pentium
SiliconDie)
Die
North Side
PKG
SKT
VSS
L1 PS
L2 GND
L3 Sig
L4 GND
L5 PWR
L6 Sig
L7 GND
L8 SS
150uF POSCAP
116
+
+
-
10x0.1uF 0603
VCCP = 1.05v
Short DATA & ADDR
Sides
Intel® 855PM Chipset Platform Design Guide
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Figure 65. Processor VCCP Power Plane and Decoupling Example
VCC-CORE
CROSS
SECTION
VIEW VIEW
Intel Pentium M
CROSS
SECTION
processor Silicon Die
South/Legacy Side Pentium M Silicon Die
North
Side
DATA
Side
Primary SIDE
ADDR
Side
VCCP
PKG
SKT
Legacy
Side
L1 PS
L2 GND
L3 Sig
L4 GND
L5 PWR
L6 Sig
L7 GND
L8 SS
VCCP To
855PM & DATA
ICH4-M Side
SECONDARY SIDE
ADDR
VCC-CORE
Side
+
+
-
VCCP
150uF POSCAP
VCCP
To ITP
GND
Vias
10x0.1uF 0603
Intel® 855PM Chipset Platform Design Guide
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5.9.4.2.
Intel 855PM MCH VCCP Voltage Plane and Decoupling
The Intel 855PM MCH conceptual VCCP (1.05 V) power delivery cross section is illustrated in Figure
66. Similar to the concept for the processor, the secondary side layer (Layer 8) that references the solid
ground plane on Layer 7 located 4 mils above (see Figure 2) creates a low inductance short between the
150-µF POSCAPs and the 0.1 µF 0603 form factor capacitors placed inside and outside of the package
shadow of the MCH on the secondary side.
Figure 66. Intel 855PM MCH VCCP Power Plane and Decoupling Concept
Hub Interface Side
PSB Side
Intel
855PM
MCH-M
Intel
855PM
MCH
855PM
Silicon
Die
VCCHA
VCCGA
150uF
POSCAP
L1 PS
L2 GND
L3 Sig
L4 GND
L5 PWR
L6 Sig
L7 GND
L8 SS
1.8v
1.05v
0.1uF 1.8v 10uF To Pentium
To Intel M
8x0.1uF 0603
0603
1206 VCCA
Pentium M
processor
VCCA
Figure 67. Intel 855PM MCH VCCP Power Plane and Decoupling Recommended Layout Example
VCCP=1.05v
PSB Side
855PM
Silicon
Die
Intel
MCH-M
Intel855PM
855PM
MCH
L1 PS
L2 GND
L3 Sig
L4 GND
L5 PWR
L6 Sig
L7 GND
L8 SS
150uF
5x0.1uF 0603
3x0.1uF 0603
Cross Section View
GND
70mil
Secondary Side
45mil
118
45mil
Intel® 855PM Chipset Platform Design Guide
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The left side of Figure 67 illustrates how the conceptual cross section (right side of Figure 67) of the
VCCP (1.05 V) plane for power delivery for the Intel 855PM MCH translates into an actual layout. The
entire section of the MCH pin-map related to the FSB signals is a flood with a VCCP plane on the
secondary side (Layer 8). Five 0603 form factor 0.1-µF capacitors are placed next to each of the VCCP
pins of the MCH pin-map on the inner rows. The VCCP pad of the capacitor is placed within (center-tocenter) 45 mils of the inner row of VCCP pins on the MCH pin-map. All the capacitors in the MCH’s
inner row of power pins are to be spaced 70 mils from each other to allow adequate spacing and
placement of the capacitors. The groundsides of the 0.1-µF capacitors are shorted with a “ring” shaped
ground flood. The groundside vias are within 45 mils of each of the ground pads of the capacitors. See
the “Zoom In View” in Figure 67. Three, 0.1-µF 0603 form factor capacitors are placed outside the
MCH cavity on the secondary side. It is important that the layout style and placement of the 0603 form
factor capacitors for VCCP as explained above in Figure 67 are closely followed to guarantee the 0.6 nH
ESL for these capacitors. For clarity, refer to the “Zoom In View” picture of the capacitor placement on
the MCH’s secondary side on the inner row pin field as illustrated on the right side of Figure 68.
One, 150-µF POSCAP placed on the secondary side (top right corner of Figure 67) close to the MCH
package body outline should also be used.
Figure 68. Intel 855PM MCH VCCP Power Delivery Recommended Layout (Zoom In View)
VCCP=1.05v
VCCP=1.05v
1.5v
1.2v
1.8v
Secondary Side
5.9.5.
GND
2.5v
Intel 855PM MCH Core Voltage Plane and Decoupling
The VCC-MCH (1.2 V) plane feeds the internal core logic of the 855PM MCH. VCC-MCH does not employ
on package decoupling. Thus, in order to guarantee an accurate VCC-MCH voltage on the MCH die, the
specific decoupling guidelines listed in Table 22 should be closely adhered to. The specific component
form factors, the layout style, and the decoupling capacitor values should also be used with no deviation
from recommendations.
The decoupling for VCC-MCH should utilize two, 150-µF POSCAPs acting as bulk decoupling capacitors
and should be placed (preferably) on the secondary side of the motherboard in the vicinity of the MCH
package shadow. The mid frequency decoupling should include a 2.2-µF, 10% 0805 form factor X7R
MLCC decoupling capacitor placed within 50 mils of the MCH’s U16 VCC-MCH pin. High frequency
decoupling consists of the careful tuning of five 0603 form factor X7R capacitors with different values
each: One, 0.22-µF, 10% capacitor; one, 47-nF, 10% capacitor; one, 22-nF, 10% capacitor; one, 15 nF,
Intel® 855PM Chipset Platform Design Guide
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10% capacitor; and one, 10-nF, 10% capacitor. All five capacitors should be placed on the secondary
side of the motherboard within 45 mils of the P17, N16, and N14 VCC-MCH pins. All the VCC-MCH power
delivery pin vias should be shorted on the secondary side of the motherboard with a solid flood and
shorted to the mid and high frequency decoupling capacitors. The primary side of the VCC-MCH should
use a flood plane to short the VCC-MCH vias while allowing some perforation due to ground and VCCHA
and VCCGA dog bones. Refer to specific layout examples below for more details.
Table 22. VCC-MCH Decoupling Guidelines
Description
Cap (µF)
Low Frequency Decoupling (Polymer Covered
Tantalum – POSCAP, Neocap, KO Cap)
2 x 150 µF
Mid Frequency Decoupling (0805 MLCC, >= X7R
10%)
1 x 2.2 µF
High Frequency Decoupling (0603 MLCC, >= X7R
10%)
ESR (m
ESL (nH)
Notes
(typ) / 2
2.5 nH / 2
2m
(typ)
730 pH
1 x 220 nF
9m
(typ)
0.6 nH
1
High Frequency Decoupling (0603 MLCC, >= X7R
10%)
1 x 47 nF
24 m
(typ)
0.6 nH
1
High Frequency Decoupling (0603 MLCC, >= X7R
10%)
1 x 22 nF
40 m
(typ)
0.6 nH
1
High Frequency Decoupling (0603 MLCC, >= X7R
10%)
1 x 15 nF
49 m
(typ)
0.6 nH
1
High Frequency Decoupling (0603 MLCC, >= X7R
10%)
1 x 10 nF
66 m
(typ)
0.6 nH
1
42 m
NOTE: To achieve the 0.6 nH ESL, the recommended layout should be followed.
Figure 69 illustrates the conceptual cross sectional view for the MCH’s VCC-MCH (1.2 V) power delivery
layout. VCC-MCH vias connect a flood on the primary side to Layer 5 and Layer 6 that are parallel
connection floods that feed the inner row of VCC-MCH pins from the voltage regulator. The vias also
continue to the secondary side flood plane under the die shadow to provide a low inductance short
between the 0805 and 0603 form factor high and mid frequency decoupling capacitors with to the VCCMCH power delivery pins. Low inductance is achieved due to a 4.5-mil separation (see Figure 2) of the
secondary side VCC-MCH flood from the Layer 7 ground plane.
The feed connections of the Layer 5 and Layer 6 VCC-MCH floods also benefit from low inductance due to
the use of the Layer 4 and Layer 7 ground planes, respectively, as reference planes with a small
dielectric separation (see Figure 2). The use of the two layers, Layer 5 and Layer 6, as feeds is required
since one of them becomes too narrow when crossing the pin-field antipads to carry the needed amount
of current without compromising voltage drop. Once Layer 5 and Layer 6 get outside the MCH package
outline, two, 150-µF POSCAPs are connected with VCC-MCH and ground vias to the Layer 5 and Layer 6
planes floods. Notice that the VCC-MCH and the ground vias are placed under the body of the POSCAPs
capacitors with about 35 mils of spacing to minimize the inductance of the capacitor connection vias.
Refer to Figure 70, which illustrates how the conceptual power delivery cross sectional view of the VCCMCH in Figure 69 translates into an actual, recommended layout as implemented on the primary side layer
(Layer 1), Layer 4, Layer 5, and the secondary side layer (Layer 8). The top left side of Figure 70 shows
how the BGA balls and the vias are shorted with a small VCC-MCH plane flood on the primary side.
Notice the orientation of the dog bones on the primary side layer (Layer 1) since this is critical to fit all
the required components on the secondary side.
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The top right side of Figure 70 shows how most of Layer 5 under the MCH package outline is a ground
plane except for a narrow corridor that allows escape of the VCC-MCH out of the pin field. This is possible
since Layer 5 does not need to be ground in this area since there are no signals routed on Layer 6 in this
area that needs to be ground referenced to Layer 5. However, due to the via antipads the VCC-MCH
corridor is fairly narrow. Thus, another somewhat wider VCC-MCH plane flood corridor is created in
between the FSB and AGP signals for escape routing on Layer 6 as illustrated on the bottom right side
of Figure 70. Both Layer 5 and Layer 6 VCC-MCH floods get connected to a VR feed point.
The bottom left side of Figure 70 illustrates how the VCC-MCH flood on the secondary side is shorted to
the four 0603 and one 2.2 µF 0805 form factor capacitors to the VCC-MCH pins. As the Layer 5 and Layer
6 VCC-MCH floods continue to the VR feed point, they are also via’ed down with the four pairs of VCC-MCH
and ground vias to connect the two, 150-µF POSCAPs placed on the secondary side layer (Layer 8).
Notice that the vias are placed under the body of the POSCAPs and connect to two small VCC-MCH and
ground floods on the secondary side that connect the vias to the POSCAP pads. This is done to
minimize the ESL of the POSCAPs in this connection.
In Figure 70 and Figure 71, placement of the POSCAPs on the secondary side is recommended since
Layer 5 and Layer 6 are much closer to the secondary side thus lower ESL will result for this
connection.
Figure 69. VCC-MCH Power Delivery and Decoupling Concept
DDR Side
855PM
ODEM
Silicon
SIL
Die
Intel
855PM
MCH-M
855PM
MCH
PSB Side
L1 PS
L2 GND
L3 Sig
L4 GND
L5 PWR
L6 Sig
L7 GND
L8 SS
2.5v
1.2v
0603 and 0805 Caps
1.05v
2x150uF POSCAPS
Figure 70 illustrates how the conceptual cross section of the VCC-MCH power delivery in Figure 69
translates into an actual recommended layout as implemented on the primary side layer (Layer 1), Layer
4, Layer 5, and secondary side layer (Layer 8). The top left side of Figure 70 shows how the BGA balls
and the vias are shorted with a small VCC-MCH plane flood on the primary side. Notice the orientation of
the dog bones since this is critical to fit all the required components on the secondary side.
The top right side of Figure 70 shows how most of Layer 5 under the Intel 855PM MCH package
outline shadow is a ground plane except for a narrow corridor that allows for the escape routing of the
VCC-MCH out of the pin field. This is possible since Layer 5 does not need to be ground in this area since
there are no signals routed on Layer 6 in this area that needs to use Layer 5 for ground referencing.
However, due to the via antipads, the VCC-MCH corridor is fairly narrow. Thus, another somewhat wider
VCC-MCH plane flood corridor is created in between the FSB and AGP signals for escape routing on
Layer 6 as illustrated in bottom right side of Figure 70. Both Layer 5 and Layer 6 VCC-MCH floods get
connected to a VR feed point.
The bottom left side of Figure 70 illustrates the VCC-MCH flood on the secondary side shorted to the five,
0603 form factor capacitors and one, 2.2-µF 0805 form factor capacitor to the VCC-MCH pins. As the
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Layer 5 and Layer 6 VCC-MCH floods continue to the VR feed point, they also are via’ed down with the
four pairs of VCC-MCH and ground vias to connect to the two, 150-µF POSCAPs placed on the secondary
side (Layer 8). Notice that the vias are placed under the body of the POSCAPs and connect to two small
VCC-MCH and ground floods on the secondary side that connect the vias to the POSCAP pads. This is
done to minimize the ESL of the POSCAPs in this connection.
In Figure 70 and Figure 71, placement of the POSCAPs on the secondary side is recommended since
Layer 5 and Layer 6 are much closer to the secondary side, thus lower ESL will result from this
connection.
Figure 70. VCC-MCH Power Planes and Decoupling Example
VR Feed
Primary Side
Layer 5
1.2v
1.2v
GND
for PSB
AGP
DDR
HL
Signals
2x150uF
Secondary
Side
1.05v
VR Feed
1.2v
Layer 6
PSB
AGP
1.5v
1.8v
1.2v
2.5v
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Figure 71 further illustrates a “Zoom In View” of the secondary side layout that was shown on the
bottom left side of Figure 70. Notice the specific locations of the 0805, 2.2-µF mid frequency capacitor
and the 0603 form factor 10 nF, 15 nF, 22 nF, 47 nF, and 220 nF high frequency decoupling capacitors.
The 0603 capacitors’ VCC-MCH side pads are placed within 45 mils of their respective row of VCC-MCH
vias. All these capacitors are shorted with the VCC-MCH flood on the secondary side plane to the VCC-MCH
vias of the pin field and the two extra vias that were added to effectively stitch the primary side, Layer 5,
Layer 6, and the secondary side VCC-MCH floods to the decoupling capacitors. The groundside of the
0603 form factor 10 nF, 15 nF, 22 nF, 47 nF, and 220 nF capacitors connect to a ground ring on the
secondary side and a stitching ground via is placed within 45 mils of the ground pad of the capacitor.
On the top left corner of Figure 71 four pairs of the VCC-MCH and ground vias connect the two small VCCand ground floods for the two 150-µF bulk decoupling POSCAPs to internal layers. The VCC-MCH
vias are offset 25 x 25 mils in the X and Y directions from the ground vias. This cluster of vias is placed
symmetrically under the middle of the body of the POSCAPs.
MCH
Figure 71. VCC-MCH Secondary Layer Decoupling Capacitor Placement (Zoom in View)
25mil
1.05v
Secondary
Side
25mil
2x150µF
0805
2.2µF
Extra Via
1.5v
1.2v
Extra Via
1.8v
0603
22nF
2.5v
45mil
45mil
0603 0603 0603 0603
10nF 47nF 15nF 220nF
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6.
System Memory Design Guidelines
(DDR-SDRAM)
The Intel 855PM chipset Double Data Rate (DDR) SDRAM system memory interface consists of 121
CMOS signals. These CMOS signals have been divided into several signal groups: Data, Command,
Control, Feedback, and Clock signals. Table 23 summarizes the different signal grouping. Refer to the
Intel® 855PM Memory Controller Hub (MCH) DDR 200/266/MHz Datasheet for details on the signals
listed.
Table 23. Intel 855PM Chipset DDR Signal Groups
Group
Data
Command
Control
Feedback
Clocks
Signal Name
Description
SDQ[63:0]
Data Bus
SDQ[71:64]
Check Bits for ECC Function
SDQS[8:0]
Data Strobes
SMA[12:0]
Memory Address Bus
SBS[1:0]
Bank Select
SRAS#
Row Address Select
SCAS#
Column Address Select
SWE#
Write Enable
SCKE[3:0]
Clock Enable - (One per Device Row)
SCS#[3:0]
Chip Select - (One per Device Row)
RCVENOUT#
Output Feedback Signal
RCVENIN#
Input Feedback Signal
SCK[5:0]
DDR-SDRAM Differential Clocks - (3 per SO-DIMM)
SCK#[5:0]
DDR-SDRAM Inverted Differential Clocks - (3 per SO-DIMM)
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6.1.
DDR 200/266/333 MHz System Memory Topology and
Layout Design Guidelines
The Intel 855PM chipset’s Double Data Rate (DDR) SDRAM system memory interface implements the
low swing, high-speed, terminated SSTL_2 topology.
This section contains information and details on the DDR topologies, the DDR layout and routing
guidelines, and the DDR power delivery requirements that will provide for a robust DDR solution on an
system incorporating the Intel 855PM chipset.
Caution: DDR System Memory Topologies for all signal groups have a relatively high via usage, please take this
into consideration for the board layout as the vias and the anti-pad for the via could restrict power
delivery to the SO-DIMMs.
Note: Simulations performed for motherboard strip-line, simulations account for different propagation delays
in strip-line only and not accounted for in micro-strip. The simulated motherboard r was 3.8 and 4.5.
Note: Intel has conducted simulations for 2x8 SO-DIMMs that are based on the 1x8 raw card B populated
with Dual Die Package (DDP) SDRAM parts based on 512-Mbit devices (two 256-Mbit dies within the
same package). For platform design details for supporting this memory type, see Section 6.1.6.
Note: In the JEDEC PC2100 DDR SDRAM Unbuffered SO-DIMM Reference Design Specification, Rev 1.0, it
is noted that pin 89 and pin 91 (CK2 and CK2#) of the SO-DIMM connector are reserved for x72
modules or registered modules. By default, the Intel 855PM MCH does not drive 3rd SCK pair to nonECC memory modules. Therefore, it is important to make sure that the memory modules are not
expected to use all clock pairs. Intel design guidelines for non-ECC memory modules assume that only 2
of 3 SCK differential clock pairs available on the MCH are used. Intel design guidelines assume that
only ECC memory modules utilize three SCK differential clock pairs.
6.1.1.
Data Signals – SDQ[71:0], SDQS[8:0]
The Intel 855PM MCH data signals are source synchronous signals that include a 64-bit wide data bus,
8 check bits for Error Checking and Correction (ECC), and 9 data strobe signals. There is an associated
data strobe (DQS) for each data (DQ) and check bit (CB) group. This section summarizes the DQ/CB to
DQS matching.
The data signals include SDQ[71:0] and SDQS[8:0]. The data signal group routing starting from the
MCH is as follows. The data signals should transition immediately from an external layer to an internal
signal layer under the MCH. Keep to the same internal layer until transitioning back to an external layer
at the series resistor. If the series resistor is on the same side of the board as SO-DIMM0 then stay on
external layer and route to appropriate pad of SO-DIMM0. If it is necessary to return to an internal
layer return to same internal layer and then return to external layer immediately prior to appropriate pad
of SO-DIMM0. If the series resistor is on the opposite side of the board then either transition to same
external layer as SO-DIMM0 and route to appropriate pad of SO-DIMM0 or return to the same internal
layer and then return to external layer immediately prior to the appropriate pad of SO-DIMM0. Continue
the route for the SO-DIMM0 pad by returning to same internal layer and transition to an external layer
immediately prior to the appropriate pad of SO-DIMM1. To connect the parallel termination resistor
either remain on same external layer as SO-DIMM1 and connect the parallel termination resistor,
transition to external layer on opposite of the board as the SO-DIMM1 and connect the parallel
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termination resistor, or transition to same internal layer and then return to external layer and connect to
the parallel termination resistor.
The data signal group byte lane and associated strobe needs to be routed on the same inner signal layer.
The data signal groups and associated strobe may be routed on different internal layers provided that the
byte lane are all routed on same internal layer. For example SDQ[7:0] and SDQS0 may be routed on
one internal layer and SDQ[15:8] and SDQS1 may be routed on a different internal layer. In addition,
match routing topology and via placement for all signals in a given byte lane including the associated
strobe. External trace lengths should be minimized. To facilitate simpler routing, swapping of the byte
lane and the associated strobe is allowed for SDQ[63:0] only. Bit swapping within the byte lane is
allowed for SDQ[63:0] only. The CB group, SDQ[71:64], cannot be byte lane swapped with another
DQ byte late. Also, bit swapping within the SDQ[71:64] byte lane is not allowed. All internal and
external signals should be ground referenced to keep the path of the return current continuous.
Resistor packs are acceptable for the series (Rs) and parallel (Rt) data and strobe termination resistors,
but data and strobe signals can’t be placed within the same R pack as the command or control signals.
The table and diagrams below depict the recommended topology and layout routing guidelines for the
DDR-SDRAM data signals.
Figure 72. Data Signal Routing Topology
Intel 855PM MCH
Rs
MCH Pkg Route
MCH
Die
P
Rt
L2
L1
L3
SO-DIMM0 PAD
V tt
L4
SO-DIMM1 PAD
The data signals should be routed using 1:2 trace to space ratio for signals within the data group. There
should be a minimum of 20 mils of spacing to non-DDR related signals and DDR clock pairs
SCK/SCK#[5:0]. Data signals should be routed on inner layers with minimized external trace lengths.
Table 24. Data Signal Group Routing Guidelines
Parameter
Routing Guidelines
Signal Group
Data – SDQ[71:0], SDQS[8:0]
Motherboard Topology
Daisy Chain with Parallel Termination
Reference Plane
Ground Referenced
Characteristic Trace Impedance (Zo)
55
Trace Width
Notes
1
±15%
Inner layers: 4 mils
Outer layers: 5 mils
Trace to Space ratio
1:2 (e.g. 4 mil trace to 8 mil space)
Group Spacing
Isolation spacing for non-DDR related
signals = 20 mils minimum
Trace Length L1 – MCH Signal Ball to Series
Termination Resistor Pad
Min = 0.5”
Trace Length L2 – Series Termination Resistor
Max = 0.75”
Intel® 855PM Chipset Platform Design Guide
Figure
Max = 3.75”
6
Figure 74
3, 5
Figure 74
3
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System Memory Design Guidelines (DDR-SDRAM)
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Pad to First SO-DIMM Pad
Trace Length L3 – First SO-DIMM Pad to Last
SO-DIMM Pad
Max = 1.0”
Figure 74
Trace Length L4 – Last SO-DIMM Pad to Parallel
Max = 0.80”
Termination Resistor Pad
Overall routing length from 855PM MCH to last
SO-DIMM Pad– L1+Rs+L2+L3 (required for
DDR333 support)
Min = 0.5”
Series Termination Resistor (Rs)
10
± 5%
Parallel Termination Resistor (Rt)
56
± 5%
Maximum Recommended Motherboard Via
Count Per Signal
6
3
Figure 74
Max= 4.5”
2, 4
SDQ[71:0] to SDQS[8:0]
Length Matching Requirements
SDQS[8:0] to SCK/SCK#[5:0]
See Section 6.2.1for details
NOTES:
1. Recommended resistor values and trace lengths may change in a later revision of the design guide.
2. Power distribution vias from Rt to Vtt are not included in this count.
3. The overall maximum and minimum length to the SO-DIMM must comply with clock length matching
requirements.
4. It is possible to route using 4 vias if trace length L2 is routed on same external layer as SO-DIMM0 and a via is
shared between SO-DIMM1 and parallel termination resistor.
5. L1 trace length does not include MCH-M package length and should not be used when calculating L1 length.
6. Implementing a space to trace ratio of 3:1 (e.g. 12-mil space to 4-mil trace) for DQS[8:0] will produce a design
with increased timing margins.
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6.1.1.1.
Data to Strobe Length Matching Requirements
The data and check bit signals, SDQ[71:0], are grouped by byte lanes and associated with a data strobe,
SDQS[8:0]. The data signals and check bit signals must be length matched to their associated strobe
within ± 25 mils provided that individual trace lengths (i.e. L1, L2, and L3) specifications are not
violated. For SO-DIMM0 this length matching includes the motherboard trace length to the pads of the
SO-DIMM0 connector (L1 + Rs Length + L2). For SO-DIMM1, the motherboard trace length to the
pads of the SO-DIMM1 connector (L1 + Rs Length + L2 + L3).
For associated SDQS Length = X and SDQ Byte Group Length = Y, the following must be met:
( X – 25 mils )
Y
( X + 25 mils )
No length matching is required from the SO-DIMM1 to the parallel termination resistors. Table 25 and
Figure 73 below depict the length matching requirements between the DQ, CB, and DQS signals.
Table 25. SDQ[71:0] to SDQS[8:0] Length Mismatch Mapping
Signal
Mismatch
Relative To
SDQ[7:0]
± 25 mils
SDQS0
SDQ[15:8]
± 25 mils
SDQS1
SDQ[23:16]
± 25 mils
SDQS2
SDQ[31:24]
± 25 mils
SDQS3
SDQ[39:32]
± 25 mils
SDQS4
SDQ[56:40]
± 25 mils
SDQS5
SDQ[55:48]
± 25 mils
SDQS6
SDQ[63:56]
± 25 mils
SDQS7
SDQ[71:64]
± 25 mils
SDQS8
Note: The recommended individual trace lengths (i.e. L1, L2, and L3) specifications can not be violated when
the signal lengths are tolerance by ± 25 mils.
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Figure 73. DQ/CB to DQS Trace Length Matching Requirements
SO-DIMM0
= Motherboard Trace Lengths
Intel 855PM
MCH Package
DQ/CB[0]
DQ/CB[1]
DQ/CB Length (Y) = (X ±25 mils)
DQ/CB[2]
DQ/CB[3]
DQS
DQS Length = X
DQ/CB[4]
DQ/CB[5]
DQ/CB Length (Y) = (X ±25 mils)
DQ/CB[6]
DQ/CB[7]
Note: Lengths are measured from MCH-M pin to SO-DIMM0
connector pads.
SO-DIMM0
SO-DIMM1
= Motherboard Trace Lengths
Intel 855PM
MCH Package
DQ/CB[0]
DQ/CB[1]
DQ/CB[2]
DQ/CB Length (Y) =
(X ±25 mils)
DQ/CB[3]
DQS
DQS Length = X
DQ/CB[4]
DQ/CB[5]
DQ/CB[6]
DQ/CB Length (Y) =
(X ±25 mils)
DQ/CB[7]
Note: Lengths are measured from MCH-M pin to SO-DIMM1
connector pads.
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6.1.1.2.
Strobe to Clock Length Matching Requirements
The data strobe signals may be up to 1.0 inches shorter or up to 0.5 inches longer than their associated
differential clock pairs.
Note: Using this formula is made simpler by routing all clocks to the associated SO-DIMM the same length,
for example SCK/SCK#[2:0] all being the same length.
Length matching equation for SO-DIMM0:
X1 = SCK/SCK#[2:0] = MCH package + L1 of Figure 72
Y1 = SDQS[8:0] = MCH package + L1 + Rs Length + L2 of Figure 72 where:
( Y1 – 0.5” )
X1
( Y1 + 1.0” )
Length matching equation for SO-DIMM1:
X2 = SCK/SCK#[5:3] = MCH package + L1 of Figure 72
Y2 = SDQS[8:0] = MCH package + L1 + Rs Length + L2 + L3 of Figure 72 where:
( Y2 – 0.5” )
X2
( Y2 + 1.0” )
For example if the total clock length of SCK/SCK#[2:0](X1) is 3.5 inches then the length of all data
strobe signal routing to SO-DIMM0 must be between 2.5 inches to 4.0 inches, if SCK/SCK#[5:3](X2) is
4.5 inches then the length of all control signal route to SO-DIMM1 must be between 3.5 inches to 5.0
inches. Figure 74 depicts the length matching requirements between the DQS and clock signals.
The MCH package lengths for clocks and strobes must be taken into account for routing length
matching.
If clocks to each SO-DIMM are routed to different lengths due to allowable tolerance, then the
strobe to clock length requirement must be met for all clock lengths. For example if the clock pairs
to SO-DIMM0 are routed at 1.975 inches for CLK0/CLK0#, 2.000 inches for CLK1/CLK1#, and
2.025 inches for CLK2/CLK2# then the strobes length (DQS) to SO-DIMM0 must be routed
between 1.025 inches to and 2.475 inches. If the CLK to one SO-DIMM is all equal in length, 2.00
inches for example then the strobes (DQS) can be routed between 1.00 inches to 2.50 inches.
Refer to Section 4.4 for package trace length data.
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Figure 74. SDQS to SCK/SCK# Trace Length Matching Requirements
SO-DIMM0
= MCH Package Lengths from Pad to Ball
= Motherboard Trace Lengths
Intel 855PM
MCH Package
MCH
DIE
SDQS[8:0]
DQS Length = Y
( Y - 0.5" ) < = X < = ( Y + 1.0" )
SCK[2:0]
SCK/SCK#[2:0] Length = X
SCK#[2:0]
Note: Lengths are measured from MCH-M pad to SO-DIMM0
connector pads.
SO-DIMM0 SO-DIMM1
= MCH Package Lengths from Pad to Ball
= Motherboard Trace Lengths
Intel 855PM
MCH Package
MCH
DIE
SDQS[8:0]
DQS Length = Y
( Y - 0.5" ) < = X < = ( Y + 1.0" )
SCK[5:3]
SCK#[5:3]
SCK/SCK#[5:3] Length = X
Note: Lengths are measured from MCH-M pad to SO-DIMM1
connector pads.
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6.1.1.3.
Data Routing Example
Figure 75 is an example of a board routing for the Data signal group. Data routing is shown in red. The
majority of the Data signal route is on an internal layer, both external layers can used for parallel
termination R-pack placement.
Figure 75. Data Signals Group Routing Example
FromIntel
Intel855PM
855PM
MCH
From
From
OdemMCH-M
Intel® 855PM Chipset Platform Design Guide
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6.1.1.4.
Support for Small Form Factor Design DDR Data Bus Routing
The layout and routing guidelines for the system memory interface of the Intel 855PM MCH have been
optimized to address the requirements of small form factor designs (i.e., mini-note, sub-note, and tablet
PCs). The design guidelines allow the routing of SDQ[71:0] and SDQS[8:0] from the MCH pin to the
series resistor (Rs) to be as short as 0.5 inches.
6.1.2.
Control Signals – SCKE[3:0], SCS#[3:0]
The Intel 855PM MCH control signals, SCKE[3:0] and SCS#[3:0], are common clocked signals. They
are “clocked” into the DDR-SDRAM devices using clock signals SCK/SCK#[5:0]. The MCH drives the
control and clock signals together, with the clocks crossing in the valid control window. The MCH
provides one chip select (CS) and one clock enable (CKE) signal per SO-DIMM physical device row.
Two chip select and two clock enable signals will be routed to each SO-DIMM. Refer to Table 26 for
the CKE and CS# signal to SO-DIMM mapping.
Table 26. Control Signal to SO-DIMM Mapping
Signal
Relative To
SO-DIMM Pin
SCS#[0]
SO-DIMM0
121
SCS#[1]
SO-DIMM0
122
SCS#[2]
SO-DIMM1
121
SCS#[3]
SO-DIMM1
122
SCKE[0]
SO-DIMM0
96
SCKE[1]
SO-DIMM0
95
SCKE[2]
SO-DIMM1
96
SCKE[3]
SO-DIMM1
95
The control signal group routing starting from MCH is as follows. The control signal routing should
transition immediately from an external layer to an internal signal layer under the MCH. Keep to the
same internal layer until transitioning back to an external layer and connect to the appropriate pad of the
SO-DIMM connector and the parallel termination resistor. If the layout requires additional routing
before the termination resistor, return to the same internal layer and transition back out to an external
layer immediately prior to parallel termination resistor.
External trace lengths should be minimized. Intel suggests that the parallel termination be placed on both
sides of the board to simplify routing and minimize trace lengths. All internal and external signals
should be ground reference to keep the path of return current continuous. Intel suggests that all control
signals be routed on the same internal layer.
Resistor packs are acceptable for the parallel (Rt) control termination resistors, but control signals can
not be placed within the same R pack as the data or command signals. The table and diagrams below
depict the recommended topology and layout routing guidelines for the DDR-SDRAM control signals.
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Figure 76. Control Signal Routing Topology
Intel 855PM MCH
Vtt
MCH Pkg Route
MCH
Die
P
Rt
L2
L1
SO-DIMM0,1 PAD
The control signals should be routed using 1:2 trace to space ratio for signals within the control group.
There should be a minimum of 20-mils of spacing to non-DDR related signals and DDR clocks
SCK/SCK#[5:0]. Control signals should be routed on inner layers with minimized external trace lengths.
Table 27. Control Signal Routing Guidelines
Parameter
Routing Guidelines
Signal Group
Control – SCKE[3:0], SCS#[3:0]
Motherboard Topology
Point-to-Point with Parallel Termination
Reference Plane
Ground Referenced
Characteristic Trace Impedance (Zo)
55
Trace Width
1
Inner layers: 4 mils
Outer layers: 5 mils
1:2 (e.g. 4 mil trace to 8 mil space)
Group Spacing
Isolation spacing for non-DDR related
signals = 20 mils minimum
Min = 0.5 inches
Max = 5.0 inches
Trace Length L2 – SO-DIMM Pad to Parallel
Termination Resistor Pad
Max = 2.0 inches
Parallel Termination Resistor (Rt)
56
Maximum Recommended Motherboard Via
Count Per Signal
3
Length Matching Requirements
Notes
±15%
Trace to Space ratio
Trace Length L1 – MCH Control Signal Ball to
SO-DIMM Pad
Figure
Figure 76
4, 5
Figure 76
± 5%
2, 3, 4
Control Signals to SCK/SCK#[5:0]
See Section 6.1.2.1 for details
NOTES:
1. Recommended resistor values and trace lengths may change in a later revision of the design guide.
2. Power distribution vias from Rt to Vtt are not included in this count.
3. It is possible to route using 2 vias if one via is shared that connects to the SO-DIMM pad and parallel termination
resistor.
4. The overall maximum and minimum length to the SO-DIMM must comply with clock length matching
requirements.
5. L1 trace length does not include MCH package length and should not be used when calculating L1 length.
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6.1.2.1.
Control to Clock Length Matching Requirements
The control signals must be 0.5 inches shorter to 1.0 inches longer than their associated differential
clock pairs.
Length matching equation for SO-DIMM0:
X1 = SCK/SCK#[2:0]
Y1 = SCS#[1:0] and SCKE[1:0] = L1of Figure 76 where:
( Y1 – 1.0” )
X1
( Y1 + 0.5” )
Length matching equation for SO-DIMM1:
X2 = SCK/SCK#[5:3]
Y2 = SCS#[3:2] and SCKE[3:2] = L1of Figure 76 where:
( Y2 – 1.0” )
X2
( Y2 + 0.5” )
For example if the clock length of SCK/SCK#[2:0](X1) is 3.5 inches then the length of all control signal
routing to SO-DIMM0 must be between 3.0 inches to 4.5 inches, if SCK/SCK#[5:3](X2) is 4.5 inches
then the length of all control signal route to SO-DIMM1 must be between 4.0 inches to 5.5 inches.
Figure 77 depicts the length matching requirements between the control and clock signals.
The MCH package lengths do not need to be taken into account for routing length matching purposes.
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Figure 77. Control Signal to SCK/SCK# Trace Length Matching Requirements
SO-DIMM0
= Motherboard Trace
Lengths
Intel 855PM
MCH Package
SCS#[1:0],
SCKE[1:0]
CNTRL Length = Y
( Y - 1.0" ) < = X < = ( Y + 0.5" )
SCK[2:0]
SCK#[2:0]
SCK/SCK#[2:0] Length = X
Note: Lengths are measured from MCH-M pins to SODIMM0 connector pads.
SO-DIMM0 SO-DIMM1
= Motherboard Trace
Lengths
Intel 855PM
MCH Package
SCS#[3:2],
SCKE[3:2]
CNTRL Length = Y
( Y - 1.0" ) < = X < = ( Y + 0.5" )
SCK[5:3]
SCK#[5:3]
SCK/SCK#[5:3] Length = X
Note: Lengths are measured from MCH-M pins to SODIMM1 connector pads.
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6.1.2.2.
Control Routing Example
Figure 78 is an example of a board routing for the Control signal group. Control routing is shown in red.
Figure 78. Control Signals Group Routing Example
FromIntel
Intel 855PM
855PM
From
MCH
From
Odem MCH-M
Control
Signals
To Parallel
Termination
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6.1.3.
Command Signals – SMA[12:0], SBS[1:0], SRAS#, SCAS#,
SWE#
The Intel 855PM MCH command signals, SMA[12:0], SBS[1:0], SRAS#, SCAS#, and SWE# are
common clocked signals. They are “clocked” into the DDR-SDRAMs using the clock signals
SCK/SCK#[5:0]. The MCH drives the command and clock signals together, with the clocks crossing in
the valid command window. There are two supported topologies for the command signal group. Section
6.1.3 is divided into two subsections; Topology 1 and Topology 2. Topology 1 is a daisy chain topology.
Topology 2 implements a T routing topology. Both topologies place a series resistor between the two
SO-DIMMs to damp SO-DIMM-to-SO-DIMM resonance. Topology 2 is the topology that best allows
for placement of the SO-DIMMs back to back in the butterfly configuration, thus minimizing the SODIMM footprint area.
6.1.3.1.
Command Topology 1 Solution
6.1.3.1.1.
Routing Description for Command Topology 1
The command signal group routing starting from Intel 855PM MCH is as follows. The command signal
routing should transition immediately from an external layer to an internal signal layer under the MCH.
Keep to the same internal layer until transitioning back to an external layer immediately prior to
connecting the SO-DIMM0 connector pad. At the via transition for SO-DIMM0, continue the signal
route on the same internal layer to the series termination resistor (Rs), collocated to SO-DIMM1. At this
resistor the signal should transition to an external layer immediately prior to the pad of Rs. After the
series resistor, Rs, continue the signal route on the external layer landing on the appropriate connector
pad of SO-DIMM1, or if necessary return to the same internal layer and return to external layer
immediately prior to the connector pad of SO-DIMM1. After SO-DIMM1, transition to the same
internal layer or stay on the external layer and route the signal to Rt.
It is suggested that the parallel termination (Rt) be placed on both sides of the board to simplify routing
and minimize trace lengths. All internal and external signals should be ground referenced to keep the
path of the return current continuous.
Resistor packs are acceptable for the series and parallel command termination resistors but command
signals can’t be placed within the same R-packs as data, strobe, or control signals. The diagrams and
tables below depict the recommended topology and layout routing guidelines for the DDR-SDRAM
command signals routing to SO-DIMM0 and SO-DIMM1. Collocating the series resistor, Rs, and SODIMM1 allows for the elimination of one via from the signal route.
Figure 79. Command Signal Routing for Topology 1
Intel 855PM MCH
MCH
Die
V tt
Rs
MCH Pkg Route
L1
P
L2
L3
L4
Rt
SO-DIMM0 PAD
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The command signals should be routed using a 1:2 trace to space ratio for signals within the command
group. There should be a minimum of 20 mils spacing to non-DDR related signals and DDR clock pairs
SCK/SCK#[5:0]. Command signals should be routed on inner layers with minimized external traces.
Table 28. Command Topology 1 Routing Guidelines
Parameter
Routing Guidelines
Signal Group
Command – SMA[12:0], SBS[1:0],
SRAS#, SCAS#, SWE#
Motherboard Topology
Daisy Chain with Parallel Termination
Reference Plane
Ground Referenced
Characteristic Trace Impedance (Zo)
55
Trace Width
Figure
Notes
1
± 15%
Inner layers: 4 mils
Outer layers: 5 mils
Trace to Space ratio
1:2 (e.g. 4 mil trace to 8 mil space)
Group Spacing
Isolation spacing for non-DDR related
signals = 20 mils minimum
Trace Length L1 – MCH Command Signal Ball to Min = 1.0 inch
First SO-DIMM Pad
Max = 4.0 inches
Figure 79
3, 5
Trace Length L2 – First SO-DIMM Pad to Series
Resistor Pad
Max = 1.1 inches
Figure 79
3
Trace Length L3 – Series Resistor Pad to
Second SO-DIMM Pad
Max = 0.2 inches
Figure 79
3
Trace Length L4 – Second SO-DIMM Pad to
Parallel Resistor Pad
Max = 0.8 inches
Figure 79
Series Termination Resistor (Rs)
10
± 5%
Parallel Termination Resistor (Rt)
56
± 5%
Maximum Recommended Motherboard Via
Count Per Signal
6
Length Matching Requirements
2, 4
Command Signals to SCK/SCK#[5:0]
See Section 6.1.3.1.2 for details
NOTES:
1. Recommended resistor values and trace lengths may change in a later revision of the design guide.
2. Power distribution vias from Rt to Vtt are not included in this count.
3. The overall maximum and minimum length to the SO-DIMM must comply with clock length matching
requirements.
4. It is possible to route using 4 vias if one via is shared that connects to the SO-DIMM1 pad and parallel
termination resistor.
5. L1 trace length does not include MCH package length and should not be used when calculating L1 length.
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6.1.3.1.2.
Command Topology 1 to Clock Length Matching Requirements
The command signals must be 0.5 inches shorter to 1.0 inches longer than their associated differential
clock pairs.
Length matching equation for SO-DIMM0:
X1 = SCK/SCK#[2:0]
Y1 = Command Signals = L1 of Figure 79 where:
( Y1 – 1.0” )
X1
( Y1 + 0.5” )
Length matching equation for SO-DIMM1:
X2 = SCK/SCK#[5:3]
Y2 = Command Signals = L1 + L2 + Rs Length + L3 of Figure 79 where:
( Y2 – 1.0” )
X2
( Y2 + 0.5” )
For example if the clock length of SCK/SCK#[2:0](X1) is 5.0 inches then the lengths of all command
signal routing to SO-DIMM0 must be between 4.5” to 6.0”, if SCK/SCK#[5:3](X2) is 5.5 inches then
the length of command signal routing to SO-DIMM1 must be between 5.0 inches to 6.5 inches. Figure
80 depicts the length matching requirements between the command and clock signals.
The MCH package lengths do not need to be taken into account for routing length matching purposes.
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Figure 80. Command Signal to SCK/SCK# Trace Length Matching Requirements
SO-DIMM0
= Motherboard Trace Lengths
Intel 855PM
MCH Package
SMA[12:0],
SBS[1:0],
RAS#, CAS#,
WE#
CMD Length = Y
( Y - 1.0" ) < = X < = ( Y + 0.5" )
SCK[2:0]
SCK/SCK#[2:0] Length = X
SCK#[2:0]
Note: CMD Lengths are measured from MCH-M
pins to SO-DIMM0 connector pads.
SO-DIMM0 SO-DIMM1
= Motherboard Trace Lengths
Intel 855PM
MCH Package
SMA[12:0],
SBS[1:0],
RAS#, CAS#,
WE#
CMD Length = Y
( Y - 1.0" ) < = X < = ( Y + 0.5" )
SCK[5:3]
SCK#[5:3]
SCK/SCK#[5:3] Length = X
Note: CMD Lengths are measured from MCH-M
pins to SO-DIMM1 connector pads.
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6.1.3.1.3.
Command Topology 1 Routing Example
Figure 81 is an example of a board routing for the Command signal group. Command routing is shown
in red.
Figure 81. Command Signals Topology 1 Routing Example
From Intel
From Odem
855PM MCH
Series
SeriesDampening
Dampening
Resistor
ResistorRs
Rs
Parallel Termination
on Both Layers
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6.1.3.2.
Command Topology 2 Solution
6.1.3.2.1.
Routing Description for Command Topology 2
The command signal group routing starting from Intel 855PM MCH is as follows. The command signal
routing should transition immediately from an external layer to an internal signal layer under the MCH.
Keep to the same internal layer until transitioning back to an external layer at the series resistor Rs. At
this point there is a T in the topology. One leg of the T will route through Rs and either transition back
to the same internal layer or stay external and landing on the appropriate connector pad of SO-DIMM0.
If it was necessary to return to the internal layer from Rs the signal should return to the external layer
immediately prior to landing on the appropriate connector pad of SO-DIMM0. The other leg of the T
will continue on the same internal layer and return to the external layer immediately prior to landing on
the appropriate connector pad of SO-DIMM1. If possible stay on the external layer and connect to the
parallel termination resistor or if the parallel termination resistor is on the opposite side of the board
from the SO-DIMM1 connector then share the via and route to the parallel termination resistor. If
sharing the via or using the opposite side of the board is not possible, continue on the same internal layer
and route to the external layer immediately prior to the termination resistor.
External trace lengths should be minimized. Intel suggests that the parallel termination be placed on both
sides of the board to simplify routing and minimize trace lengths. All internal and external signals
should be ground referenced to keep the path of the return current continuous. It is recommended that
command signal group be routed on same internal layer.
It is suggested that the parallel termination (Rt) be placed on both sides of the board to simplify routing
and minimize trace lengths. All internal and external signals should be ground referenced to keep the
path of the return current continuous.
Resistor packs are acceptable for the series and parallel command termination resistors, but command
signals can not be placed within the same R-packs as data, strobe or control signals. The diagrams and
tables below depict the recommended topology and layout routing guidelines for the DDR-SDRAM
command signals routing to SO-DIMM0 and SO-DIMM1.
Figure 82. Command Signal Routing for Topology 2
Intel 855PM MCH
Vtt
MCH Pkg Route
MCH
Die
P
L3
L1
L4
Rt
Rs
SO-DIMM1 PAD
L2
SO-DIMM0 PAD
The command signals should be routed using 1:2 trace to space ratio for signals within the command
group. There should be a minimum of 20 mils of spacing to non-DDR related signals and DDR clock
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pairs SCK/SCK#[5:0]. Command signals should be routed on inner layers with minimized external trace
lengths.
Table 29. Command Topology 2 Routing Guidelines
Parameter
Routing Guidelines
Signal Group
Command – SMA[12:0], SBS[1:0], SRAS#,
SCAS#, SWE#
Motherboard Topology
Daisy Chain with Parallel Termination
Reference Plane
Ground Referenced
Characteristic Trace Impedance (Zo)
55
Trace Width
Figure
Notes
1
± 15%
Inner layers: 4 mils
Outer layers: 5 mils
Trace to Space ratio
1:2 (e.g. 4 mil trace to 8 mil space)
Group Spacing
Isolation spacing for non-DDR related
signals = 20 mils minimum
Trace Length L1 – MCH Command Signal Ball to Min = 0.5 inches
Series Resistor 1 Pad
Max = 5.0 inches
Figure 82
3, 5
Trace Length L2 – Series Resistor Pad to First
SO-DIMM Pad
Figure 82
3
Figure 82
3
Trace Length L3 – Series Resistor Load to
Second SO-DIMM Pad
Max = 1.0 inches
Min = 0.4 inches
Max = 1.75 inches
Trace Length L4 – Second SO-DIMM Pad to
Parallel Resistor Pad
Max = 0.25 inches
Series Termination Resistor (Rs)
10
± 5%
Parallel Termination Resistor (Rt)
56
± 5%
Maximum Recommended Motherboard Via
Count Per Signal
6
Length Matching Requirements
Figure 82
2, 4
Command Signals to SCK/SCK#[5:0]
See Section 6.1.3.2.2 for details
NOTES:
1. Recommended resistor values and trace lengths may change in a later revision of the design guide.
2. Power distribution vias from Rt to Vtt are not included in this count.
3. The overall maximum and minimum length to the SO-DIMM must comply with clock length matching
requirements.
4. It is possible to route using 3 vias if one via is shared that connects L1, L3, and series termination and if one via
is shared that connects to the SO-DIMM1 pad and parallel termination resistor.
5. L1 trace length does not include MCH package length and should not be used when calculating L1 length.
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6.1.3.2.2.
Command Topology 2 to Clock Length Matching Requirements
The command signals must be 0.5 inches shorter to 1.0 inches longer than their associated differential
clock pairs.
Length matching equation for SO-DIMM0:
X1 = SCK/SCK#[2:0]
Y1 = Command Signals = L1 + Rs Length + L2 of Figure 82 where:
( Y1 – 1.0” )
X1
( Y1 + 0.5” )
Length matching equation for SO-DIMM1:
X2 = SCK/SCK#[5:3]
Y2 = Command Signals = L1 + L3 of Figure 82 where:
( Y2 – 1.0” )
X2
( Y2 + 0.5” )
For example if the clock length of SCK/SCK#[2:0](X1) is 5.0 inches then the length of all command
signal routing to SO-DIMM0 must be between 4.5 inches to 6.0 inches, if SCK/SCK#[5:3](X2) is 5.5
inches then the length of command signal routing to SO-DIMM1 must be between 5.0 inches to 6.5
inches. Figure 83 depicts the length matching requirements between the command and clock signals.
The MCH package lengths do not need to be taken into account for routing length matching purposes.
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Figure 83. Command Signal to SCK/SCK# Trace Length Matching Requirements
= Motherboard
Trace Lengths
Intel 855PM
MCH Package
SO-DIMM0
SMA[12:0],
SBS[1:0],
RAS#, CAS#,
WE#
CMD Length = Y
( Y - 1.0" ) < = X < = ( Y + 0.5" )
SCK[2:0]
SCK/SCK#[2:0] Length = X
SCK#[2:0]
Note: CMD Lengths are measured from MCH-M
pins to SO-DIMM0 connector pads.
= Motherboard
Trace Lengths
Intel 855PM
MCH Package
SO-DIMM0 SO-DIMM1
SMA[12:0],
SBS[1:0],
RAS#, CAS#, WE#
CMD Length = Y
( Y - 1.0" ) < = X < = ( Y + 0.5" )
SCK[5:3]
SCK#[5:3]
SCK/SCK#[5:3] Length = X
Note: CMD Lengths are measured from MCH-M
pins to SO-DIMM1 connector pads.
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6.1.3.2.3.
Command Topology 2 Routing Example
Figure 84 is an example of a board routing for the Command signal group. Command routing is shown
in red.
Figure 84. Command Signals Topology 2 Routing Example
From
From
Intel
Intel
855PM
From
Odem
MCH-M
855PM
MCH
Command
Signals
Series Resistors
(On reverse side
of the board then
the SO-DIMMs)
Could be RPacks
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6.1.4.
Clock Signals – SCK[5:0], SCK#[5:0]
The clock signal group includes the differential clock pairs SCK[5:0] and SCK#[5:0]. The Intel 855PM
MCH generates and drives these differential clock signals required by the DDR interface; therefore, no
external clock driver is required for the DDR interface. The MCH only supports unbuffered DDR SODIMMs, three differential clock pairs are routed to each SO-DIMM connector. Table 30 summarizes the
clock signal mapping.
Table 30. Clock Signal Mapping1
NOTE:
Signal
Relative To
SCK[2:0], SCK#[2:0]
SO-DIMM0
SCK[5:3], SCK#[5:3]
SO-DIMM1
Assummes no clock pair swapping between SO-DIMMs and actual implementation may vary.
The one to one mapping of the clocks from the MCH to the SO-DIMM is not required. For example, it
is not necessary that the SCKn/SCK#n clock pair from the MCH route to the same number clock on the
SO-DIMM0 connector, which is CKn/CK#n in the PC2100 DDR SDRAM Unbuffered SO-DIMM
Reference Design Specification. This changing of clock numbering from MCH to SO-DIMMs may
require additional BIOS setting changes. Swapping SCK and SCK# within a differential pair is not
allowed. e.g. SCK1 and SCK1# may not be swapped at the SO-DIMM connector.
The clock differential pair routing starting from MCH is as follows. The clock differential pair routing
should transition immediately from an external layer to an internal signal layer under the MCH and route
as a differential pair referenced to ground for the entire length to their associated SO-DIMM connector
pads. Immediately prior to the SO-DIMM connector the signals should transition to the same external
layer as the SO-DIMM and connect the appropriate pad of the SO-DIMM connector.
External trace lengths should be minimized. All internal and external signal routing should be ground
referenced to keep the path of the return current continuous. The diagrams and table below depict the
recommended topology and layout routing guidelines for the DDR-SDRAM differential clocks.
Figure 85. DDR Clock Routing Topology (SCK/SCK#[5:0])
Intel 855PM MCH
MCH Pkg Route
MCH
Die
P
L1
SO-DIMM0,1 PAD
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Table 31. Clock Signal Group Routing Guidelines
Parameter
Routing Guidelines
Signal Group
Clock – SCK[5:0], SCK#[5:0]
Motherboard Topology
Differential Pair Point-to-Point
Reference Plane
Ground Referenced
Characteristic Trace Impedance (Zo)
55
Trace Width (Option 1)
Trace Width (Option 2)
Differential Trace Spacing
Group Spacing
Notes
1
± 15% (single ended)
Inner layers: 4 mils
5, 6
Outer layers: 5 mils
Inner layers: 7 mils
5, 6
Outer layers: 8 mils
Inner layers: 4 mils
2
Outer layers: 5 mils
Isolation spacing from another DDR signal
group = 20 mils minimum
Isolation spacing for non-DDR related
signals = 20 mils minimum
Trace Length L1 – MCH Clock Signal Ball to SO- Min = 0.5”
DIMM Pad
Max = 5.5”
Maximum Recommended Motherboard Via
Count Per Signal
Figure
Figure 85
3, 4
2
SCK/SCK#[5:0]
Length Matching Requirements
The 3 SO-DIMM0 clock pairs are equal in
length plus tolerance and the 3 SO-DIMM1
clock pairs are equal in length plus
tolerance
See Section 6.1.4.1 for details
Clock Pair-to-Pair tolerance
± 25 mils
SCK to SCK# tolerance
± 10 mils
NOTES:
1. Recommended trace lengths may change in a later revision of the design guide.
2. Spacing between SCK and SCK# within each differential pair should be implemented as follows with the
following clock trace widths: for microstrips use 4-mil spacing, 4-mil or 7-mil trace width; for striplines use 5-mil
spacing, 5-mil or 8-mil trace width.
3. The overall maximum and minimum length to the SO-DIMM must comply with DDR signal length matching
requirements.
4. L1 trace length does not include MCH package length and should not be used when calculating L1 length.
5. Routing SCK/SCK# to a 7-mil trace width with 4-mil spacing is included as a design enhancement option.
Simulations show improved timing margin resulting from use of a 7-mil clock trace width.
6. Option 1 OR Option 2 must be implemented for all SCK/SCK# pairs for a given design. The two options should
not be combined within one design.
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6.1.4.1.
Clock Signal Length Matching Requirements
The Intel 855PM MCH provides three differential clock pair signals for each SO-DIMM. A differential
clock pair is made up of a SCK signal and its complement signal SCK#.
The differential pairs for one SO-DIMM are:
SCK[0] / SCK#[0]
SCK[1] / SCK#[1]
SCK[2] / SCK#[2]
The differential pairs for the second SO-DIMM are:
SCK[3] / SCK#[3]
SCK[4] / SCK#[4]
SCK[5] / SCK#[5]
The differential clock pairs’ motherboard routing must be matched to ± 25 mils. Each SCK to SCK# pair
motherboard routing must be matched to ± 10 mils. Figure 86 and Figure 87 depict the length matching
requirement between SCK/SCK# and clock pairs, respectively.
For information covering the data and data strobe to clock length matching requirements reference
Section 6.1.1.2, for information covering the control signal to clock length matching requirements
reference Section 6.1.2.1, and for information covering the command signal to clock length matching
requirements reference Section 6.1.3.1.2 for Topology 1 and Section 6.1.3.2.2 for Topology 2. Refer
Section 6.1.5.1 for package trace length data.
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Figure 86. SCK/SCK# Trace Length Matching Requirements
SO-DIMM0
= Motherboard Trace Lengths
Intel 855PM
MCH Package
SCK0
SCK0 Length = X0
SCK#0 Length = X0#
|X0 - X0# | <= 0.01 inches
SCK#0
SCK1
SCK1 Length = X1
SCK#1 Length = X1#
|X1 - X1# | <= 0.01 inches
SCK#1
SCK2
SCK2 Length = X2
SCK#2 Length = X2#
|X2 - X2# | <= 0.01 inches
SCK#2
Note: Lengths are measured from MCH-M pin to SODIMM0 connector pads.
SO-DIMM0 SO-DIMM1
= Motherboard Trace Lengths
Intel 855PM
MCH Package
SCK3
SCK#3
SCK4
SCK#4
SCK5
SCK#5
SCK3 Length = Y0
SCK#3 Length = Y0#
|Y0 - Y0# | <= 0.01 inches
SCK4 Length = Y1
SCK#4 Length = Y1#
|Y1 - Y1# | <= 0.01 inches
SCK5 Length = Y2
SCK#5 Length = Y2#
|Y2 - Y2# | <= 0.01 inches
Note: Lengths are measured from MCH-M pin to SODIMM1 connector pads.
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Figure 87. Clock Pair Trace Length Matching Requirements1
SO-DIMM0
= Motherboard Trace Lengths
Intel 855PM
MCH Package
SCK/SCK#[0]
SCK/SCK#[1]
SCK/SCK#[0] Length = X0/X0#
SCK/SCK#[1] Length = X1/X1#
SCK/SCK#[2] Length = X2/X2#
SCK/SCK#[2]
Max (X0,X0#,X1,X1#,X2,X2#) - Min (X0,X0#,X1,X1#,X2,X2#) <= 0.025 inches
Note: Lengths are measured from MCH-M pin to SO-DIMM0
connector pads.
SO-DIMM0
SO-DIMM1
= Motherboard Trace Lengths
Intel 855PM
MCH Package
SCK/SCK#[3]
SCK/SCK#[4]
SCK/SCK#[3] Length = Y0/Y0#
SCK/SCK#[4] Length = Y1/Y1#
SCK/SCK#[5] Length = Y2/Y2#
SCK/SCK#[5]
Max (Y0,Y0#,Y1,Y1#,Y2,Y2#) - Min (Y0,Y0#,Y1,Y1#,Y2,Y2#) <= 0.025 inches
Note: Lengths are measured from MCH-M pin to SO-DIMM1
connector pads
NOTE: Length matching between DQS and Clock pairs must include package length.
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6.1.4.1.1.
Clock Routing Example
Figure 88 is an example of a board routing for the Clock signal group. Clock routing is shown in red.
Figure 88. Clock Signal Routing Example
Intel
855PM
Odem
MCH
MCH-M
Clocks
SO-DIMM0
SO-DIMM1
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6.1.4.2.
Intel 855PM Chipset High Density Memory Support
The 855PM chipset architecture supports 2-GB of system memory. This memory capacity can be
achieved using “high-density” memory devices of various package types. Intel has done only limited
simulation and bench testing on these high-density SO-DIMM memory modules and has not seen any
functional or analog inspection failures using existing layout guidelines. Due to a lack of JEDEC
standard for high density memory; however, Intel has not done complete simulation nor validation with
all the available package configurations. Customers are strongly encouraged to perform complete
validation on their platforms based on the particular high-density memory package of their choice.
6.1.5.
Feedback – RCVENOUT#, RCVENIN#
The Intel 855PM MCH provides a feedback signal called “receive enable” (RCVEN#), which is used to
gate the strobe inputs for read data. There are two pins on the MCH to facilitate the use of RCVEN#.
The RCVENOUT# pin is an output of the MCH and the RCVENIN# pin is an input to the MCH.
RCVENOUT# must connect directly to RCVENIN#.
The diagrams and table below depict the recommended topology and layout routing guidelines for the
DDR-SDRAM feedback signal. The RCVEN# signal must be routed on the same layer as the
system memory clocks. The RCVEN# routing starting from MCH is as follows. RCVEN# should
transition immediately from the same external signal layer as MCH to the same internal signal layer as
memory clocks under the MCH, routed referenced to ground for the entire length. RCVEN# should then
transition from the internal signal layer back to the same external layer as MCH and connect the
RCVENIN# of MCH. External trace lengths should be minimized. All internal (segment L2) and
external layer signal routing (segments L1 and L3) should be ground referenced to keep the path of the
return current continuous.
Figure 89. DDR Feedback (RCVEN#) Routing Topology
Intel 855PM MCH
Intel 855PM MCH
MCH Pkg Route
MCH
Die
P
MCH Pkg Route
L1
Intel® 855PM Chipset Platform Design Guide
L2
L3
P
MCH
Die
155
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Table 32. Feedback Signal Routing Guidelines
Parameter
Routing Guidelines
Signal Group
Feedback – RCVENOUT#, RCVENIN#
Motherboard Topology
Point-to-Point
Reference Plane
Ground Referenced
Characteristic Trace Impedance (Zo)
55
Trace Width
Group Spacing
Trace Length L1 – MCH Feedback Signal Pin to
Signal Via
Figure
Notes
1
± 15% (single ended)
Inner layers: 4 mils
Outer layers: 5 mils
Isolation spacing from another DDR signal
group = 20 mils minimum
Isolation spacing for non-DDR related signals
= 20 mils minimum
Max = 40 mils
Figure 89
Trace Length L2 – MCH RCVENOUT# Signal Via
Must = 100 mils ± 5mils
to RCVENIN# Signal Via
Figure 89
Trace Length L3 – Signal Via to MCH Feedback
Signal Pin
Max = 40 mils
Figure 89
Maximum Recommended Motherboard Via
Count Per Signal
2
Length Matching Requirements
None
2
3
NOTES:
1. Recommended trace lengths may change in a later revision of the design guide.
2. L1 trace length does not include MCH package length and should not be used when calculating L1 length.
3. L3 trace length does not include MCH package length and should not be used when calculating L3 length.
6.1.5.1.
RCVEN# Routing Example
Figure 90 is an example of a board routing implementation for the RCVEN# signal. Clock routing is
show in red.
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Figure 90. RCVEN# Signal Routing Example
Intel
OdemMCH-M
Intel855PM
855PM
MCH
MCH-M
MCH
Pin
Pin
RCVEN# on
external layer
Vias
RCVEN# on
same internal
layer as clocks
Clocks
6.1.6.
Support for “DDP Stacked” SO-DIMM Modules
Simulations have been performed to verify the suitability of the DDR layout and routing guidelines to
support the use of 512-Mbit technology-based (two 256-Mbit dies within the same package), “DDP
stacked”, 2x8 SO-DIMM memory modules on Intel 855PM chipset based platforms. For the purpose of
this discussion, the term “DDP stacked” is used to refer to DDP SDRAM based 2x8 SO-DIMM memory
modules. Based on these simulations, the current routing guidelines can support this type of stacked
memory device. Other stacked devices have not been simulated and therefore cannot be recommended.
Please see Section 6.1.4 for clock signal group related routing updates.
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6.1.7.
Recommended Design Option to Support PC2700 DDR SDRAM
with Existing PC1600 and PC2100 Intel 855PM Platforms
The following sections document the currently available design option for enabling PC2700 DDR
SDRAM support based on existing platform layouts.
6.1.7.1.
Shortened Data Signal Group Trace Length
Modifications to current platforms to support PC2700 are possible by reducing the overall motherboard
trace length for the data signal group if current trace lengths exceed the PC2700 trace length guidelines.
This includes all DDR data signals, SDQ[71:0], and data strobe signals, SDQS[8:0].
Design guidelines for supporting PC2700 based on an existing PC1600 and PC2100 layout are
presented in Section 6.2.7.1.1. A list of general design considerations for adapting current platforms to
support PC2700 is summarized in Section 6.2.7.1.2.
6.1.7.1.1.
Supporting PC2700 Based on an Existing PC Platform Layout
While the maximum length of L1, L2, L3, and L4 remains unchanged from previous revisions of this
design guide, the maximum overall length allowed from the MCH-M to the second SO-DIMM (L1 + Rs
+ L2 + L3) for PC2700 support is limited to 4.5 inches. This represents a reduction of 1.0 inches
compared to that allowed for PC2100 and PC1600 design guidelines. As a result, platforms based on
current PC2100 and PC1600 layout guidelines may require a reduction in trace lengths of up to 1.0
inches, in order to meet the PC2700 maximum data signal group length requirements.
Figure 91. Data Signal Group (SDQ[71:0], SDQS[8:0]) Routing Topology – PC2700, PC2100 and
PC1600 Compliant
Rs
MCH Pkg Route
MCH
Die
P
Rt
L2
L1
L3
V tt
L4
SO-DIMM1 PAD
SO-DIMM0 PAD
Table 33. Data Signal Group (SDQ[71:0], SDQS[8:0]) Routing Guidelines – PC2700, PC2100 and
PC1600 Compliant
DDR Data Signal Group (for
platform supporting PC2700,
PC2100, PC1600 DDR
SDRAM)
DDR Data Signal Group
(for platform supporting
PC2100 and PC1600
DDR
SDRAM)
158
L1
L2
L3
Min = 0.5”
Min = 0”
Min = 0”
Max = 3.75” Max = 0.75” Max = 1.0”
Min = 0.5”
Min = 0”
Min = 0”
Max = 3.75” Max = 0.75” Max = 1.0”
L4
Min = 0”
Max =
0.8”
Min = 0”
Max =
0.8”
Rs
Rt
L1 + Rs +
L2 + L3
22.6
± 1%
54.9 ±
1%
Min = 0.5”
22.6
± 1%
54.9 ±
1%
Max = 4.5”
Min = 0.5”
Max =5.5”
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6.1.7.1.2.
Additional Design Considerations for Adapting Intel 855PM DDR 200/266 MHz
Platforms To Support PC2700
In addition to meeting the updated routing length requirements specified in Section 6.2.7.1, future DDR
333-MHz platforms must also adhere to all other existing design guidelines for the DDR 200-MHz and
266-MHz platforms. Table34 contains section references to all other existing design guidelines that need
to be followed for the different signal groups.
Table 34. Existing PC2100/PC1600 DDR SDRAM Design Guidelines Required for PC2700 Support
Group
Signal
Section Reference
Data
SDQ[71:0]; SDQS[8:0]
6.2.1
Control
SCKE[3:0]; SCS#[3:0]
6.2.2
Command
SMA[12:0]; SBS[1:0]; SRAS#; SCAS#; SWE#
6.2.3
Clock
SCK[5:0]; SCK#[5:0]
6.2.4
Feedback
RCVENOUT#; RCVENIN#
6.2.5
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6.2.
Intel 855PM MCH DDR Signal Package Lengths
The signals listed in Table 35 are routed with 55 ± 15% micro-strip transmission lines. Signals within
the same group are trace length matched within 0.1 mils inside the package. Thus, motherboard routing
does not need to compensate for trace length mismatch in the package for these signals.
Table 35. Intel 855PM Chipset DDR Signal Package Lengths
Data Signal Name
Intel 855PM MCH Package
Trace Length (mils)
Data Signal Name
DATA GROUP 1
Intel 855PM MCH Package
Trace Length (mils)
DATA GROUP 6
SDQ[7:0]
945
SDQ[47:40]
732
SDQS[0]
945
SDQS[5]
732
DATA GROUP 2
DATA GROUP 7
SDQ[15:8]
873
SDQ[55:48]
850
SDQS[1]
873
SDQS[6]
850
DATA GROUP 3
DATA GROUP 8
SDQ[23:16]
765
SDQ[63:56]
950
SDQS[2]
765
SDQS[7]
950
DATA GROUP 4
DATA GROUP 9
SDQ[31:24]
658
SDQ[71:64]
646
SDQS[3]
658
SDQS[8]
646
DATA GROUP 5
SDQ[39:32]
649
SDQS[4]
649
DIFFERENIAL CLOCKS
SCK[5:0]
661
SCK[5:0]#
661
COMMAND – SMA
SMA[0]
462
SMA[7]
515
SMA[1]
441
SMA[8]
446
SMA[2]
481
SMA[9]
523
SMA[3]
537
SMA[10]
404
SMA[4]
434
SMA[11]
536
SMA[5]
548
SMA[12]
538
SMA[6]
510
COMMAND – SBS
SBS[0]
160
423
SBS[1]
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Data Signal Name
Intel 855PM MCH Package
Trace Length (mils)
Data Signal Name
Intel 855PM MCH Package
Trace Length (mils)
COMMAND – Misc
SCAS#
491
SWE#
401
SRAS#
447
CONTROL – SCKE
SCKE[0]
557
SCKE[2]
506
SCKE[1]
600
SCKE[3]
573
CONTROL – SCS#
SCS#[0]
516
SCS#[2]
516
SCS#[1]
539
SCS#[3]
610
RECEIVE ENABLE
RCVENOUT#
6.3.
661
RCVENIN#
348
DDR System Memory Interface Strapping
The Intel 855PM MCH has pins that require termination for proper component operation.
For the MCH, the ST[0] pin does not require any strapping for normal operation. This signal has an
internal pull-up that straps the MCH for DDR memory during reset. However, a stuffing option for a 1k ± 5% pull-up to a 1.5-V source can be provided for testing purposes.
6.4.
ECC Disable Guidelines
The Intel 855PM MCH can be configured to operate in an ECC data integrity mode that allows for
multiple bit error detection and single bit error correction. This option to design for and support ECC
DDR memory modules is dependent on design objectives. By default, ECC functionality is disabled on
the platform. For designs that support ECC memory, see Sections 6.1.1 and 6.1.4 for details on signal
topologies and routing guidelines.
6.4.1.
Intel 855PM MCH ECC Functionality Disable
If non-ECC memory modules are to be the only supported memory type on the platform, then the eight
DDR check bits signals, associated strobe, and differential clock pairs associated with the ECC device
for each SO-DIMM can be left as no connects on the Intel 855PM MCH. This includes SDQ[71:64],
SDQS8, and the two differential clock pairs that are not routed to the SO-DIMMs. The following
discussion mentions details for the MCH system memory registers.
The DRAM Data Integrity Mode (DDIM) bit of the DRC register (Device 0; Offset 7C-7Fh; bit 21)
provides the option to enable or disable ECC operation mode in the MCH. By default, this bit is set to
‘0’ and ECC functionality is disabled. In such a case, the SDQ[71:64] and SDQS eight pins of the MCH
can be left as no connects.
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The DRAM Clock Control Disable Register (DCLKDIS: I/O Address 2E-2Fh) provides the capability to
enable and disable the CS/CKE and SCK signals to unpopulated SO-DIMMs. Although DDR SODIMM connectors may provide motherboard lands for three clock pairs, Intel design recommendations
only support non-ECC SO-DIMMs that require two pairs. The MCH provides the flexibility to route any
differential clock pair to any SCK clock pair on the SO-DIMMs provided that the BIOS enables/disables
these clocks appropriately (e.g. the MCH’s SCK0 pair can be routed either to the SO-DIMM’s SCK0
pair or any other pair such as SCK1 or SCK2, etc.). By default, the enable/disable bits for the clock pairs
are set to ‘1’ and are disabled or tri-stated. To further reduce EMI/noise and save power, the SCK clock
pair pins of the MCH that are normally routed to ECC devices on ECC memory modules can be left as
no connects.
On platforms where ECC memory is supported, it is important that all relevant SDQ, SDQS, and SCK
signals to the SO-DIMMs be disabled when the system is populated with only non-ECC or a
combination of ECC and non-ECC memory. In such cases, the registers mentioned above must be
programmed appropriately.
6.4.2.
DDR Memory ECC Functionality Disable
It is imperative that systems that do not support ECC memory ensure the SCK clock pairs that are
normally sent to ECC SO-DIMMs be disabled. If the SCK clock pairs associated with the check bit
signals were left floating in a non-ECC memory only system and ECC memory was used in one or more
of the SO-DIMM slots, this could cause the ECC device on the SO-DIMM to be enabled. If SDQ[71:64]
is disabled/tri-stated or not routed, then these floating inputs can cause the ECC device to draw current
and potentially compromise the ECC device.
Previous revisions of this design guide provided guidelines that required additional hardware
termination to address the potential issue of floating inputs on an ECC SO-DIMM when populated in a
non-ECC memory only system. Since then, further analysis has been done and the new recommendation
is that no hardware termination is required on the SDQ[71:64], SDQS8, and SCK clock pair inputs of
the SO-DIMM connector.
This simplifies and provides the most reasonable hardware design recommendation that offers tradeoffs
between protecting any ECC memory inadvertently populated into the system vs. utilizing all physical
memory available in a system while incurring no power penalty.
6.5.
System Memory Compensation
See Section 11.5.4 for details.
6.6.
SMVREF Generation
See Section 11.5.3.1 for details.
6.7.
DDR Power Delivery
See Section 11.5 for details.
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6.8.
External Thermal Sensor Based Throttling (ETS#)
The Intel 855PM MCH’s ETS# input pin is an active low input that can be used with an external thermal
sensor to monitor the temperature of the DDR SO-DIMMs for a possible thermal condition. Assertion of
ETS# will result in the limiting of DRAM bandwidth on the DDR memory interface to reduce the
temperature in the vicinity of the system memory.
By default, the functionality and input buffer associated with ETS# are disabled. Also, the MCH can be
programmed to send an SERR, SCI, or SMI message to the ICH4-M upon the assertion of this signal.
External thermal sensors that are suitable for the purpose described above would need to have a small
form factor and be able to accurately monitor the ambient temperature in the vicinity of the DDR system
memory.
Intel is currently in the process of enabling this feature on the MCH and is actively engaging with
thermal sensor vendors to ensure compatibility and suitability of vendors’ products with the ETS# pin.
This includes electrical design guidelines for the ETS# pin and usage/placement guidelines of the
thermal sensors for maximum effectiveness. Current third party vendor product offerings that may be
suitable for the ETS# pin application include ambient temperature thermal sensors and remote diode
thermal sensors. Also, thermal sensors that implement an open-drain output for signaling a thermal event
would provide the most flexibility from an electrical and layout design perspective.
6.8.1.
ETS# Usage Model
The thermal sensors targeted for this application with the Intel 855PM MCH’s ETS# are planned to be
capable of measuring the ambient temperature only and should be able to assert ETS# if the
preprogrammed thermal limits/conditions are met or exceeded. Because many variables within a mobile
system can affect the temperature measured at any given point in a system, the expected usage and
effectiveness of ETS# is also very focused. Because of factors such as thermal sensor placement, airflow
within a mobile chassis, adjacent components, thermal sensor sensitivity, and thermal sensor response
time, ETS# can effectively be used for controlling skin temperatures. However, due to the location of
the thermal sensor ETS# should not be used for measuring or controlling the Tj or Tcase parameters of
DDR-SDRAM devices since it cannot respond quickly enough to dynamic changes in DRAM power.
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6.8.2.
ETS# Design Guidelines
ETS#, as implemented in the Intel 855PM MCH, is an active low signal and does not have an integrated
pull-up to maintain a logic ‘1’. As a result of this, a placeholder for an external 8.2-k to 10-k pull-up
resistor should be provided near the ETS# pin. Electrical details on output characteristics of suitable
thermal sensors for use with the MCH are currently not finalized. The recommended pull-up voltage for
this external pull-up is 2.5 V (VCCSM). Ideally, the thermal sensor should implement an open drain
type output buffer to drive ETS#. A system is expected to have one thermal sensor per SO-DIMM
connector on the motherboard. As a result, routing guidelines for the output of these thermal sensors to
the ETS# pin will also be important.
Routing guidelines and other special, motherboard design considerations will vary with the vendor and
type of thermal sensor chosen for this ETS# application. As a result, vendor specific design guidelines
should also be followed closely to ensure proper operation of this feature. As a general rule, system
designers should follow good design practices in ensuring good signal integrity on this signal as well as
achieving adequate isolation from adjacent signals. Also, any thermal design considerations (e.g. proper
ground flood placement underneath the external thermal sensor; proper isolation of the differential
signal routing for thermal diode applications, etc.) for the external thermal sensor itself should also be
met.
6.8.3.
Thermal Sensor Placement Guidelines
The many factors that can affect the accuracy of ambient temperature measurements by thermal sensors
make the placement of them a very critical and especially challenging task. Ideally, one thermal sensor
should be placed near each SO-DIMM in a system. The thermal sensor should be located in an area
where the effects of airflow and effects of conduction from adjacent components are minimized. This
allows for the best correlation of thermal sensor temperature to chassis or notebook surface temperature.
Refer to Figure 92 for details.
Assuming airflow is negligible within a system, the optimal placement of the thermal sensor is on the
surface of the motherboard directly beneath the shadow of an SO-DIMM module centered longitudinally
and laterally in relation to the outline of the SO-DIMM. The thermal sensor should have a form factor
small enough to allow it to fit beneath double-sided memory modules (i.e. modules with memory
devices on both sides of a module). If placement within the outline of an SO-DIMM is not possible, then
the next best option is to locate it within approximately 15 mm (0.6 inches) of the outline/SO-DIMM
shadow. Again, this assumes negligible effects from airflow.
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Figure 92. DDR Memory Thermal Sensor Placement
15mm
15mm
Hashed Area:
Recommended area for
DRAM ETS# sensor on
motherboard.
Best Location is sensor
under S0-DIMM. May not
be mechanically feasible in
all designs due to small
gap between SO-DIMM
and motherboard.
Top View – SO-DIMM
Side View – SO-DIMM
Sensor location within approx 15mm of
SO-DIMM outline will not be as
effective at controlling fast transient
temperature changes
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7.
AGP Port Design Guidelines
For detailed AGP interface functionality (e.g., protocols, rules, signaling mechanisms), refer to the latest
AGP Interface Specification, Revision 2.0, which can be obtained from http://www.agpforum.org. This
design guide focuses only on specific Intel 855PM chipset platform recommendations.
7.1.
AGP Interface
The AGP Interface Specification Revision 2.0 enhances the functionality of the original AGP Interface
Specification (revision 1.0) by allowing 4X data transfers (4 data samples per clock) and 1.5-volt
operation. In addition to these major enhancements, additional performance enhancement and
clarifications, such as fast write capability, are included in Revision 2.0 of the AGP Interface
Specification.
The 4X operation of the AGP interface provides for “quad-sampling” of the AGP AD (Address/Data)
and SBA (Side-band Addressing) buses. That is, the data is sampled four times during each 66-MHz
AGP clock. This means that each data cycle is ¼ of a 15 ns period (66-MHz clock) or 3.75 ns. It is
important to realize that 3.75 ns is the data cycle time, not the clock cycle time. During 2X operation,
the data is sampled twice during a 66-MHz clock cycle. Therefore, the data cycle time is 7.5 ns.
In order to allow for these high-speed data transfers, the 2X mode of AGP operation uses source
synchronous data strobing. During 4X operation, the AGP interface uses differential source synchronous
data strobing. However, differential source synchronous data strobing is not strictly required by the AGP
specification.
With data cycle times as small as 3.75 ns, and setup/hold times of 1 ns, propagation delay mismatch is
critical. In addition to reducing propagation delay mismatch, it is important to minimize noise. Noise on
the data lines will cause the settling time to be large. If the mismatch between a data line and the
associated strobe is too great, or there is noise on the interface, incorrect data will be sampled.
The low-voltage operation on AGP (1.5 V) requires even more noise immunity. For example, during
1.5-V operation, Vilmax is 570 mV. Without proper isolation, crosstalk could create signal integrity
issues.
A single AGP controller is supported by the Intel 855PM MCH AGP interface. LOCK# and
SERR#/PERR# are not supported. The AGP buffers operate in only one mode:
AGP 4X, 2X and 1X operate at 1.5 V only.
AGP semantic cycles to DRAM are not snooped on the host bus.
The MCH supports PIPE# or SBA[7:0] AGP address mechanisms, but not both simultaneously. Either
the PIPE# or the SBA[7:0] mechanism must be selected during system initialization.
The AGP interface is clocked from the 66-MHz clock input to the MCH, 66IN. The AGP interface is
synchronous to the host and system memory interfaces with a clock ratio of 2:3 (66 MHz: 100 MHz)
and to the hub interface with a clock ratio of 1:1 (66 MHz: 66 MHz).
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7.2.
AGP 2.0 Spec
7.2.1.
AGP Interface Signal Groups
The signals on the AGP interface are broken into three groups: 1X timing domain signals, 2X/4X timing
domain signals, and miscellaneous signals. Each group has different routing requirements. In addition,
within the 2X/4X timing domain signals, there are three sets of signals. All signals in the 2X/4X timing
domain must meet minimum and maximum trace length requirements as well as trace width and spacing
requirements. The signal groups are documented in the following table.
Table 36. AGP 2.0 Signal Groups
1X timing domain
CLK (3.3 V)
RBF#
WBF#
ST[2:0]
PIPE#
REQ#
GNT#
PAR
FRAME#
IRDY#
TRDY#
STOP#
DEVSEL#
2X / 4X timing domain
Set #1
AD[15:0]
C/BE[1:0]#
AD_STB0
AD_STB0#
1
Set #2
AD[31:16]
C/BE[3:2]#
AD_STB1
AD_STB1#
1
Set #3
SBA[7:0]
SB_STB
SB_STB#
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Miscellaneous, Asynchronous
USB+
USBOVRCNT#
PME#
TYPDET#
PERR#
SERR#
INTA#
INTB#
NOTE:
These signals are used in 4X AGP mode ONLY.
Table 37. AGP 2.0 Data/Strobe Associations
Data
Associated Strobe in 1X
Associated
Strobe in 2X
Associated
Strobes in 4X
AD[15:0] and C/BE[1:0]#
Strobes are not used in 1X
mode. All data is sampled on
rising clock edges.
AD_STB0
AD_STB0,
AD_STB0#
AD[31:16] and C/BE[3:2]#
Strobes are not used in 1X
mode. All data is sampled on
rising clock edges.
AD_STB1
AD_STB1,
AD_STB1#
SBA[7:0]
Strobes are not used in 1X
mode. All data is sampled on
rising clock edges.
SB_STB
SB_STB,
SB_STB#
Throughout this section, the term data refers to AD[31:0], C/BE[3:0]#, and SBA[7:0]. The term strobe
refers to AD_STB[1:0], AD_STB#[1:0], SB_STB, and SB_STB#. When the term data is used, it refers
to one of the three sets of data signals, as in Table 37. When the term strobe is used, it refers to one of
the strobes as it relates to the data in its associated group.
The routing guidelines for each group of signals (1X timing domain signals, 2X/4X timing domain
signals, and miscellaneous signals) will be addressed separately.
7.3.
AGP Routing Guidelines
7.3.1.
1x Timing Domain Routing Guidelines
7.3.1.1.
Trace Length Requirements for AGP 1X
This section contains information on the 1X-timing domain routing guidelines. The AGP 1X timing
domain signals (refer to Table 36) have a maximum trace length of 10 inches. The target impedance is
55- ± 15%. This maximum applies to ALL of the signals listed as 1X timing domain signals in Table
36. In addition to this maximum trace length requirement (refer to Table 38 and Table 39) these signals
must meet the trace spacing and trace length mismatch requirements in Sections 7.3.1.2 and 7.3.1.3.
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Table 38. Layout Routing Guidelines for AGP 1X Signals
7.3.1.2.
1X signals
Max. Length (inches)
Width (mils)
Space (mils)
CLK_AGP_SLT
10
4
4
AGP_PIPE#
10
4
4
AGP_RBF#
10
4
4
AGP_WBF#
10
4
4
AGP_ST[2:0]
10
4
4
AGP_FRAME#
10
4
4
AGP_IRDY#
10
4
4
AGP_TRDY#
10
4
4
AGP_STOP#
10
4
4
AGP_DEVSEL#
10
4
4
AGP_REQ#
10
4
4
AGP_GNT#
10
4
4
AGP_PAR
10
4
4
Trace Spacing Requirements
AGP 1X timing domain signals (refer to Table 36) can be routed with 4-mil minimum trace separation.
7.3.1.3.
Trace Length Mismatch
There are no trace length mismatch requirements for 1X timing domain signals. These signals must meet
minimum and maximum trace length requirements.
7.3.2.
2X/4X Timing Domain Routing Guidelines
7.3.2.1.
Trace Length Requirements for AGP 2X/4X
These trace length guidelines apply to ALL of the signals listed as 2X/4X timing domain signals in
Table 36. In addition to these maximum trace length requirements, these signals must meet the trace
spacing and trace length mismatch requirements in Sections 7.3.2.2 and 7.3.2.3.
The maximum line length and mismatch requirements are dependent on the routing rules used on the
motherboard. These routing rules were created to give design freedom by making tradeoffs between
signal coupling (trace spacing) and line lengths. These routing rules are divided by trace spacing. In 1:2
spacing, the distance between the traces is two times the width of traces. Simulations in a mobile
environment support this rule.
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Figure 93. AGP Layout Guidelines
(Width:Space)
Always 1:2 Strobe to Strobe# Routing
Always 1:3 Strobe to Data Routing
Intel 855PM
MCH
1:2 routing
6.0” max length
+/-0.1” mismatch
AGP
Controller
If the AGP interface is less than 6.0 inches, 1:2 trace spacing is required for 2X/4X lines. These 2X/4X
signals must be matched to their associated strobe within ± 0.1 inches. This is for designs that require
less than 6 inches between the graphics device and the Intel 855PM MCH. See Figure 93 for details.
Reduce line length mismatch to ensure added margin. In order to reduce trace to trace coupling (cross
talk), separate the traces as much as possible.
7.3.2.2.
Trace Spacing Requirements
AGP 2X/4X timing domain signals (refer to Table 36) must be routed as documented in Table 39. They
should be routed using 4-mil traces. Additionally, the signals can be routed with 5-mil spacing when
breaking out of the Intel 855PM MCH. The routing must widen to the requirement in Table 40 within
0.3 inches of the MCH package.
Since the strobe signals (AD_STB0, AD_STB0#, AD_STB1, AD_STB1#, SB_STB, and SB_STB#) act
as clocks on the source synchronous AGP interface, special care should be taken when routing these
signals. Because each strobe pair is truly a differential pair, the pair should be routed together (e.g.
AD_STB0 and AD_STB0# should be routed next to each other). The two strobes in a strobe pair should
be routed on 4-mil traces with 8 mils of space (1:2) between them. This pair should be separated from
the rest of the AGP signals (and all other signals) by at least 15 mils (1:3). The strobe pair must be
length matched to less than ± 0.1 inches (that is, a strobe and its compliment must be the same length
within ± 0.1 inches).
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Table 39. Layout Routing Guidelines for AGP 2X/4X Signals
Signal
7.3.2.3.
Maximum
Length (inch)
Trace Space
(mils)
(4 mil traces)
Length
Mismatch
(inch)
Relative To
Notes
2X/4X Timing
Domain Set#1
6
8
± 0.1
AGP_ADSTB0 and
AGP_ADSTB0#
AGP_ADSTB0,
AGP_ADSTB0# must
be the same length
(±10 mils)
2X/4X Timing
Domain Set#2
6
8
± 0.1
AGP_ADSTB1 and
AGP_ADSTB1#
AGP_ADSTB1,
AGP_ADSTB1# must
be the same length
(±10 mils)
2X/4X Timing
Domain Set#3
6
8
± 0.1
AGP_SBSTB and
AGP_SBSTB #
AGP_SBSTB,
AGP_SBSTB# must be
the same length (±10
mils)
Trace Length Mismatch Requirements
Table 40. AGP 2.0 Data Lengths Relative to Strobe Length
Max Trace Length
Trace Spacing
Strobe Length
Min Trace Length
Max Trace Length
< 6 in
1:2
X
X – 0.1 in
X + 0.1 in
The trace length minimum and maximum (relative to strobe length) should be applied to each set of
2X/4X timing domain signals independently. That is, if AD_STB0 and ADSTB0# are 5 inches, then
AD[15:0] and C/BE[1:0] must be between 4.9 inches and 5.1 inches. However AD_STB1 and
ADSTB1# can be 3.5 inches (and therefore AD[31:16] and C/BE#[3:2] must be between 3.4 inches and
3.6 inches). In addition, all 2X/4X timing domain signals must meet the maximum trace length
requirements.
All signals should be routed as strip lines (inner layers).
All signals in a signal group should be routed on the same layer. Routing studies have shown that
these guidelines can be met. The trace length and trace spacing requirements must not be violated
by any signal. Trace length mismatch for all signals within a signal group should be as close to 0
inches as possible to provide optimal timing margin.
Table 41 shows the AGP 2.0 routing summary.
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Table 41. AGP 2.0 Routing Guideline Summary
Signal
Maximum
Length
Trace
Spacing
(4 mil
traces)
Length Mismatch
Relative To
Notes
1X Timing Domain
10 in
4 mils
No Requirement
N/A
None
2X/4X Timing
Domain Set#1
6 in
8 mils
± 0.1 in
AD_STB0 and
AD_STB0#
AD_STB0, AD_STB0#
must be the same
length
2X/4X Timing
Domain Set#2
6 in
8 mils
± 0.1 in
AD_STB1 and
AD_STB1#
AD_STB1, AD_STB1#
must be the same
length
2X/4X Timing
Domain Set#3
6 in
8 mils
± 0.1 in
SB_STB and
SB_STB#
SB_STB, SB_STB#
must be the same
length
Miscellaneous
10 in
8 mils
No Requirement
N/A
PCI_PME#,
AGP_PERR#,
AGP_SERR#
Each strobe pair must be separated from other signals by at least 15 mils.
7.3.3.
AGP Clock Skew
The maximum total AGP clock skew, between the Intel 855PM MCH and the graphics component, is 1
ns for all data transfer modes. This 1 ns includes skew and jitter, which originates on the motherboard,
add-in module (if used), and clock synthesizer. Clock skew must be evaluated not only at a single
threshold voltage, but also at all points on the clock edge that falls in the switching range. The 1 ns skew
budget is divided such that the motherboard is allotted 0.9 ns of clock skew (the motherboard designer
shall determine how the 0.9 ns is allocated between the board and the synthesizer).
7.3.4.
AGP Signal Noise Decoupling Guidelines
The main focus of these guidelines is to minimize signal integrity problems on the AGP interface of the
Intel 855PM MCH. The following guidelines are not intended to replace thorough system validation on
Intel 855PM chipset-based products.
A minimum of six 0.01-µF capacitors are required and must be as close as possible to the MCH.
These should be placed within 70 mils of the outer row of balls on the MCH for VDDQ
decoupling. Ideally, this should be as close as possible.
The designer should evenly distribute placement of decoupling capacitors in the AGP interface
signal field.
Intel recommends that the designer use a low-ESL ceramic capacitor, such as with a 0603 bodytype X7R dielectric.
In order to add the decoupling capacitors within 70 mils of the MCH and/or close to the vias, the
trace spacing may be reduced as the traces go around each capacitor. The narrowing of space
between traces should be minimal and for as short a distance as possible (1.0 inch max.).
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In addition to the minimum decoupling capacitors, the designer should place bypass capacitors at vias
that transition the AGP signal from one reference signal plane to another. One extra 0.01-±F capacitor
per 10 vias is required. The capacitor should be placed as close as possible to the center of the via field.
7.3.5.
AGP Routing Ground Reference
Intel strongly recommends that at least the following critical signals be referenced to ground from the
MCH to an AGP controller connector using a minimum number of vias on each net: AD_STB0,
AD_STB0#, AD_STB1, AD_STB1#, SB_STB, SB_STB#, G_TRDY#, G_IRDY#, G_GNT#, and
ST[2:0].
In addition to the minimum signal set listed previously, Intel strongly recommends that half of all AGP
signals be referenced to ground, depending on the board layout. In an ideal design, the complete AGP
interface signal field would be referenced to ground. This recommendation is not specific to any
particular PCB stack-up, but should be applied to all systems incorporating the Intel 855PM chipset.
7.3.6.
Pull-ups
The AGP 2.0 Specification requires AGP control signals to have pull-up resistors to VDDQ to ensure
they contain stable values when no agent is actively driving the bus. Also, the AD_STB[1:0]# and
ST_STB# strobes require pull-down resistors to GND. The Intel 855PM MCH has integrated many of
these pull-up/pull-down resistors on the AGP interface and a few other signals not required by the AGP
2.0 Specification. Pull-ups are allowed on any signal except AD_STB[1:0]# and ST_STB#.
The MCH has no support for the PERR# and SERR# pins of an AGP graphics controller that supports
PERR# and SERR#. Pull-ups to a 1.5-V source are required down on the motherboard in such cases.
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Table 42. AGP Pull-Up/Pull-Down Requirements and Straps
Signal
AGP 2.0 Signal
Pull-Up/Pull-Down
Requirements
Intel
855PM
MCH Integrated
Pull-Up/Pull-Down
DEVSEL#
Pull-Up
4.5 k Pull-Up
FRAME#
Pull-Up
4.5 k Pull-Up
GNT#
4.5 k Pull-Up
State During
RSTIN# Assertion
Pull-Up (Strap)
Notes
6
INTA#
Pull-Up
3, 5
INTB#
Pull-Up
3, 5
IRDY#
Pull-Up
PERR#
Pull-Up
PIPE#
Pull-Up
4.5 k Pull-Up
RBF#
Pull-Up
4.5 k Pull-Up
REQ#
4.5 k Pull-Up
2
Pull-Up (Strap)
4.5 k Pull-Up
SERR#
1
Pull-Up
ST[2:0]
2
4.5 k Pull-Up
STOP#
Pull-Up
4.5 k Pull-Up
TRDY#
Pull-Up
4.5 k Pull-Up
WBF#
4.5 k Pull-Up
AD_STB[1:0]
Pull-Up
4.5 k Pull-Up
AD_STB[1:0]#
Pull-Down
4.5 k Pull-Down
SB_STB
Pull-Up
4.5 k Pull-Up
SB_STB#
Pull-Down
SBA[7:0]
6
Pull-Up (Strap)
4, 6
Pull-Up (Strap)
6
Pull-Up (Strap)
1, 6
4.5 k Pull-Down
4.5 k Pull-Up
NOTES:
1. The Intel 855PM MCH has integrated pull-ups to ensure that these signal do not float when there is no add-in
card in the connector.
2. The Intel 855PM MCH does not implement the PERR# and SERR# signals. Pull-ups on the motherboard are
required for AGP graphics controllers that implement these signals.
3. The AGP graphics controller’s INTA# and INTB# signals must but routed to the system PCI interrupt request
handler where the pull-up requirement should be met. For Intel 855PM chipset-based systems, they can be
routed to the ICH4-M’s PIRQ signals that are open drain and require pull-ups on the motherboard.
4. ST[1:0] provide the strapping options for 100-MHz FSB operation and DDR memory, respectively.
5. INTA# and INTB# should be pulled to 3.3 V, not VDDQ.
®
6. Refer to the Intel 855PM Memory Controller Hub (MCH) DDR 200/266 MHz Datasheet for more details on
straps.
The pull-up/pull-down resistor value requirements are shown in Table 43.
Table 43. AGP 2.0 Pull-up Resistor Values
Rmin
Rmax
4k
16 k
The recommended AGP pull-up/pull-down resistor value is 8.2 k .
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7.3.7.
AGP VDDQ and VREF
AGP specifies two separate power planes: VCC and VDDQ. VCC is the core power for the graphics
controller. VDDQ is the interface voltage. The external graphics controller may ONLY power the Intel
855PM MCH AGP I/O buffers with 1.5-V VDDQ power pins.
7.3.8.
VREF Generation for AGP 2.0 (2X and 4X)
7.3.8.1.
1.5-V AGP Interface (2X/4X)
In order to account for potential differences between VDDQ and GND at the Intel 855PM MCH and
graphics controller, both devices use source generated Vref. That is, the Vref signal is generated at the
graphics controller and sent to the MCH and another Vref is generated at the MCH and sent to the
graphics controller.
Both the graphics controller and the MCH are required to generate Vref. The voltage divider networks
consist of AC and DC elements. The reference voltage that should be supplied to the Vref pins of the
MCH and the graphics controller is ½ * VDDQ. Two 1-k ± 1% resistors can be used to divide VDDQ
down to the necessary voltage level.
The Vref divider network should be placed as close to the AGP interface as is practical to get the benefit
of the common mode power supply effects. However, the trace spacing around the Vref signals must be
a minimum of 25 mils to reduce crosstalk and maintain signal integrity.
7.3.9.
AGP Compensation
The Intel 855PM MCH AGP interface supports resistive buffer compensation. For Printed Circuit
Boards with characteristics impedance of 55 , tie the GRCOMP pin to a 36.5 ± 1% pull-down
resistor (to ground) via a 10-mil wide, very short ( 0.5 inches) trace.
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8.
Hub Interface
The Intel 855PM MCH and Intel 82801DBM ICH4-M pin-map assignments have been optimized to
simplify the hub interface routing between these devices. Intel recommends that the hub interface
signals be routed directly from the MCH to the ICH4-M with all signals referenced to VSS. Layer
transitions should be kept to a minimum. If a layer change is required, use only two vias per net and
keep all data signals and associated strobe signals on the same layer.
The hub interface signals are broken into two groups: data signals (HI) and strobe signals (HI_STB). For
the 11-bit hub interface, HI[10:0] are associated with the data signals while HI_STB and HI_STB# are
associated with the strobe signals.
Figure 94. Hub Interface Routing Example
HI_STB#
Intel
HI_STB
HI[10:0]
ICH4-M
CLK66
CLK66
Intel
855PM
MCH
CLK
Synthesizer
8.1.
Hub Interface Compensation
This hub interface connects the 82801DBM ICH4-M and the Intel 855PM MCH. The hub interface uses
a compensation signal to adjust buffer characteristics to the specific board characteristic. The hub
interface requires resistive compensation (RCOMP).
The trace impedance must equal 55-
± 15%
Table 44. Hub Interface RCOMP Resistor Values
Component
8.2.
Trace Impedance
HICOMP Resistor Value
HICOMP Resistor Tied to
ICH4-M
55
± 15%
36.5
± 1%
VSS
MCH
55
± 15%
36.5
± 1%
Vcc1_8
Hub Interface Data HI[7:0] and Strobe Signals
The hub interface HI[7:0] data signals should be routed on the same layer as hub interface strobe
signals. There are two options for routing and include either an external layer or an internal layer.
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8.2.1.
Internal Layer Routing
Traces should be routed 4 mils wide with 8 mils trace spacing (4 on 8) and 20 mils spacing from other
signals. In order to break out of the Intel 855PM MCH and Intel 82801DBM ICH4-M packages, the
HI[7:0] signals can be routed 4 on 4. The signal must be separated to 4 on 8 within 300 mils from the
package.
The maximum HI[7:0] signal trace length is 6 inches. The HI[7:0] signals must be matched within ± 100
mils of the HI_STB differential pair. There is no explicit matching requirement between the individual
HI[7:0] signals.
The hub interface strobe signals should be routed as a differential pair, 4 mils wide with 8 mils trace
spacing (4 on 8). The maximum length for strobe signals is 6 inches. Each strobe signal must be the
same length and each HI[7:0] signal must be matched to within ± 100 mils of the strobe signals.
Table 45. Hub Interface Signals Internal Layer Routing Summary
Signal
8.2.2.
Max
length
(inch)
Width
(mils)
Space
(mils)
Mismatch
length
(mils)
Relative To
Space with
other signals
(mils)
HI_[7:0]
6
4
8
± 100
Differential
HI_STB pair
20
HI_STB
and
HI_STB#
6
4
8
±100
Data lines
20
Notes
HI_STB and
HI_STB# must
be the same
length (± 10
mils)
External Layer Routing
Traces should be routed 5 mils wide with 10 mils trace spacing (5 on 10) and 20 mils spacing from other
signals. In order to break out of the Intel 855PM MCH and Intel 82801DBM ICH4-M packages, the
HI[7:0] signals can be routed 5 on 5. The signals must be separated to 5 on 10 within 300 mils from the
package.
The hub interface strobe signals should be routed as a differential pair, 5 mils wide with 10 mils trace
spacing (5 on 10). The maximum length for the strobe signals is 6 inches. Each strobe signal must be the
same length, and each HI[7:0] signal must be matched to within ± 100 mils of the strobe signals.
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Table 46. Hub Interface Signals External Layer Routing Summary
Signal
8.3.
Max
length
(inch)
Width
(mils)
Space
(mils)
Mismatch
length
(mils)
Relative To
Space with
other signals
(mils)
HI_[7:0]
6
5
10
± 100
Differential
HI_STB pair
20
HI_STB
and
HI_STB#
6
5
10
± 100
Data lines
20
Notes
HI_STB and
HI_STB# must
be the same
length (± 10
mils)
Hub Interface Data HI[10:8] Signals
The maximum length for the hub interface data signals, HI[10:8] is 8 inches. They should be routed on
the same layer with Hl[7:0].
8.3.1.
Internal Layer Routing
Traces should be routed 4 mils wide with 8 mils trace spacing (4 on 8) and 20 mils spacing from other
non-hub interface related signals. In order to break out of the Intel 855PM MCH and Intel 82801DBM
ICH4-M packages, the HI[10:8] signals can be routed 4 on 4. The signal must be separated to 4 on 8
within 300 mils from the package.
8.3.2.
External Layer Routing
Traces should be routed 5 mils wide with 10 mils trace spacing (5 on 10) and 20 mils spacing from other
non-hub interface signals. In order to break out of the Intel 855PM MCH and Intel 82801DBM ICH4-M
packages, the HI[10:8] signals can be routed 5 on 5. The signal must be separated to 4 on 8 within 300
mils from the package.
8.3.3.
Terminating HI[11]
The HI[11] signal exists on the Intel 82801DBM ICH4-M but not the Intel 855PM MCH and is not used
on the platform. It can be left as a no connect.
8.4.
HIREF/HI_VSWING Generation/Distribution
HIREF is the hub interface reference voltage used on both the Intel 855PM MCH and the Intel
82801DBM ICH4-M. Depending on the buffer mode, the HIREF voltage requirement must be set
appropriately for proper operation. The ICH4-M uses HI_VSWING to control voltage swing and
impedance strength of the hub interface buffers. See the table below for the HIREF and HI_VSWING
voltage specifications and the associated resistor recommendations for the voltage divider circuit.
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Table 47. Hub Interface HIREF/HI_VSWING Generation Circuit Specifications
HI_VSWING Voltage
1
Specification (V)
HIREF Voltage 1
Specification (V)
1/2 VCC1_8 ± 7%
1/2 VCC1_8 ± 7%
Recommended Resistor Values for the
HIREF Divider Circuit (Ohm)
R1 = R2 = (100 – 150)
± 1%
C1 = 0.01 µF
C2 = 0.1 µF
NOTE:
7% tolerance includes static and transient tolerances. HIREF and HI_VSWING must track VCC1_8 and to
this end must be ± 2% relative to the instantaneous value of VCC1_8.
The single HIREF divider should not be located more than 3 inches away from either the MCH or
ICH4-M. If the single HIREF divider is located more than 3 inches away, locally generated hub
interface reference voltage dividers should be used instead. The reference voltage generated by a single
HIREF divider should be bypassed to ground with a 0.1-µF capacitor (C2) and at each component with
a 0.01-µF capacitor (C1) located close to the component HIREF pin. If the reference voltage is
generated locally, the bypass capacitor (0.01 µF) needs to be close to the component HIREF pin.
Figure 95. Hub Interface with Single Reference Voltage Divider Circuit
VCC HI=1.8V
Intel
R1
Intel 855PM
MCH
ICH4-M
HIREF
HI_VSWING
HIREF
C1
R2
C2
C1 C1
Figure 96. Hub Interface with Locally Generated Reference Voltage Divider Circuit
VCC HI=1.8V
R1
HI_VSWING
HIREF
Intel
ICH4-M
R2
C1
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8.5.
Hub Interface Decoupling Guidelines
The main focus of these guidelines is to minimize signal integrity problems on the hub interface of the
Intel 855PM MCH. To improve I/O power delivery, use two 0.1-µF capacitors per each component (i.e.
the ICH4-M and MCH). These capacitors should be placed within 150 mils from each package, adjacent
to the rows that contain the hub interface. If the layout allows, wide metal fingers running on the VSS
side of the board should connect the VCC1_8 side of the capacitors to the VCC1_8 power balls.
Similarly, if layout allows, metal fingers running on the VCC1_8 side of the board should connect the
GND side of the capacitors to the VSS power balls.
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9.
I/O Subsystem
9.1.
IDE Interface
This section contains guidelines for connecting and routing the Intel 82801DBM ICH4-M IDE interface.
The ICH4-M has two independent IDE channels. This section provides guidelines for IDE connector
cabling and motherboard design, including component and resistor placement, and signal termination for
both IDE channels. The ICH4-M has integrated the series resistors that have been typically required on
the IDE data signals (PDD[15:0] and SDD[15:0]) running to the two ATA connectors. While it is not
anticipated that additional series termination resistors will be required, OEMs should verify motherboard
signal integrity through simulation. Additional external 0- resistors can be incorporated into the design
to address possible noise issues on the motherboard. The additional resistor layout increases flexibility
by offering stuffing options at a later date.
The IDE interface can be routed with 5-mil traces on 7-mil spaces, and must be less than 8 inches long
(from ICH4-M to IDE connector). Additionally, the maximum length difference between the shortest
data signal and the longest strobe signal of a channel is 0.5 inches.
9.1.1.
Cabling
Length of cable: Each IDE cable must be equal to or less than 18 inches.
Capacitance: Less than 35 pF.
Placement: A maximum of 6 inches between drive connectors on the cable. If a single drive is
placed on the cable it should be placed at the end of the cable. If a second drive is placed on the
same cable, it should be placed on the next closest connector to the end of the cable (6 inches
away from the end of the cable).
Grounding: Provide a direct low impedance chassis path between the motherboard ground and
hard disk drives.
Intel 82801DBM ICH4-M Placement: The ICH4-M must be placed equal to or less than 8
inches from the ATA connector(s).
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9.1.2.
Primary IDE Connector Requirements
Figure 97. Connection Requirements for Primary IDE Connector
22 to 47Ω
†
PCIRST#
PDD[15:0]
PDA[2:0]
PDIOR#
®
Intel
ICH4-M
PDIOW#
PDDREQ
PDDACK#
3.3V
3.3V
4.7K
8.2~10K
PIORDY (PRDSTB / PWDMARDY#)
Primary IDE Connector
PDCS[3,1]#
IRQ[14]
PDIAG# / CBLID#
GPIOx
CSEL
10K
† Due to ringing,
PCIRST# must be
buffered
Figure 96 highlights the requirements for routing the ICH4-M IDE interface to the primary IDE
connector.
22 - 47 series resistors are required on RESET#. The correct value should be determined for
each unique motherboard design, based on signal quality.
An 8.2 k
- 10 k
pull-up resistor is required on IRQ14 to VCC3_3.
A 4.7-k
pull-up resistor to VCC3_3 is required on PIORDY and SIORDY.
Series resistors can be placed on the control and data lines to improve signal quality. The resistors
are placed as close to the connector as possible. Values are determined for each unique
motherboard design.
The 10-k resistor to ground on the PDIAG#/CBLID# signal is required on the Primary
Connector. This change is to prevent the GPI pin from floating if a device is not present on the
IDE interface.
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9.1.3.
Secondary IDE Connector Requirements
Figure 98. Connection Requirements for Secondary IDE Connector
22 - 47Ω
PCIRST# †
SDA[2:0]
SDCS[3,1]#
SDIOR#
®
Intel
ICH4-M
SDIOW#
SDDREQ
SDDACK#
3.3V
3.3V
4.7K
8.2~10K
SIORDY (SRDSTB / SWDMARDY# )
Secondary IDE Connector
SDD[15:0]
IRQ[15]
PDIAG# / CBLID#
GPIOy
CSEL
10K
† Due to ringing,
PCIRST# must be
buffered
Figure 97 highlights the requirements for routing ICH4-M IDE interface to the secondary IDE
connector.
22 - 47 series resistors are required on RESET#. The correct value should be determined for
each unique motherboard design, based on signal quality.
An 8.2 k
- 10 k
pull-up resistor is required on IRQ15 to VCC3_3.
A 4.7-k
pull-up resistor to VCC3_3 is required on PIORDY and SIORDY.
Series resistors can be placed on the control and data lines to improve signal quality. The resistors
are placed as close to the connector as possible. Values are determined for each unique
motherboard design.
The 10-k resistor to ground on the PDIAG#/CBLID# signal is required on the Secondary
Connector. This change is to prevent the GPI pin from floating if a device is not present on the IDE
interface.
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9.1.4.
Mobile IDE Swap Bay Support
Systems that require the support for an IDE “hot” swap drive bay can be designed to utilize the Intel
82801DBM ICH4-M’s IDE interface disable feature to achieve this functionality. To support a mobile
“hot” swap bay, the ICH4-M allows the IDE output signals to be tri-stated or driven low and input
buffers to be turned off. This requires certain hardware and software requirements to be met for proper
operation.
From a hardware perspective, the equivalent of two spare control signals (e.g. GPIO’s) and a FET are
needed to properly utilize the IDE tri-state feature. An IDE drive must have a reset signal (i.e. first
additional control signal) driving its reset pin and a power supply that is isolated from the rest of the
IDE interface. To isolate the power supplied to the IDE drive bay, a second additional control signal is
needed to control the enabling/disabling of a FET that supplies a separate plane flood powering the IDE
drive and its interface.
Although actual hardware implementations may vary, the isolated reset signal and power plane are strict
requirements. Systems that connect the IDE swap bay drive to the same power plane and reset signals of
the ICH4-M should not use this IDE tri-state feature. Many IDE drives use the control and address lines
as straps that are used to enter test modes. If the IDE drive is powered up along with the ICH4-M while
the IDE interface is tri-stated rather than being driven to the default state, then the IDE drive could
potentially enter a test mode. To avoid such a situation, the aforementioned hardware requirements or
equivalent solution should be implemented.
9.1.4.1.
Intel 82801DBM ICH4-M IDE Interface Tri-State Feature
The new IDE interface tri-state capabilities of the Intel 82801DBM ICH4-M also include a number of
configuration bits that must be programmed accordingly for proper system performance. The names of
the critical registers, their location, and brief description are listed below.
1. B0:D31:F0 Offset D5h (BACK_CNTL – Backed Up Control Register) bits [7:6] need to be set to
‘1’ in order to enable the tri-stating of the primary and secondary IDE pins when the interfaces are
put into reset. By default both bits are set to ‘1.’
2. B0:D31:F0 Offset D0-D3h (GEN_CNTL – General Control Register) bit [3] should be set to ‘1’
in order to lock the state of bits [7:6] at B0:D31:F0 Offset D5h. This prevents any inadvertent
reprogramming of the IDE interface pins to a non-tri-state mode during reset by a rogue software
program. By default this bit is set to ‘0’ and BIOS should set this bit to ‘1.’ This is a write once bit
only and requires a PCIRST# to reset to ‘0.’ Thus, this bit also needs to be set to ‘1’ after resume
from S3-S5.
3. B0:D31:F1 Offset 54h (IDE_CONFIG – IDE I/O Configuration Register) bits [19:18]
(SEC_SIG_MODE) and bits [17:16] (PRIM_SIG_MODE) control the reset states of the
secondary and primary IDE channels, respectively. The values in SEC_SIG_MODE and
PRIM_SIG_MODE are tied to the values set by the BACK_CNTRL register bits [7:6],
respectively. When bits [7:6] are set to ‘1,’ the PRIM_SIG_MODE and SEC_SIG_MODE will be
set to ‘01’ for tri-state when the either IDE channel is put in reset.
4. B0:D31:F1 Offset 40-41h (Primary) and 42-23h (Secondary) bit [5] and bit [1] (IDE_TIM – IDE
Timing Register) are the IORDY Sample Point Enable bits for drive 1 and 0 of the primary and
secondary IDE channels, respectively. By default, these bits are set to ‘0’ and during normal
power up, should be set to ‘1’ by the BIOS to enable IORDY assertion from the IDE device when
an access is requested.
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9.1.4.2.
S5/G3 to S0 Boot Up Procedures for IDE Swap Bay
The procedures listed below summarize the steps that must be followed during power up of an IDE
swap bay drive.
1. ICH4-M powers up, IDE interface is tri-stated, disk drive is not powered up. IDE drive is
recognized as being on a separate power plane and its reset is different from the ICH4-M.
2. BIOS powers on the IDE drive. e.g. GPIO is used to switch on a FET on the board.
3. Once the IDE drive and interface is powered up, the ICH4-M exits from tri-state mode and begins
to actively drive the interface.
4. Once ready, the BIOS can de-assert the reset signal to the IDE drive. e.g. GPIO routed to the IDE
drive’s reset pin.
9.1.4.3.
Power Down Procedures for Mobile Swap Bay
The procedures listed below summarize the steps that must be followed in order to remove an IDE
device from the mobile swap bay.
1. User indicates to the system that removal of IDE device from the mobile swap bay should begin.
Once the system recognizes that all outstanding IDE accesses have completed, the reset signal to
the swap device should be asserted.
2. The IDE channel (primary or secondary) that the device resides on should then be set to drive low
mode rather than the default tri-state mode. This requires setting the IDE_CONFIG register
(B0:D31:F0 Offset 54h) bits [19:18] or [17:16] to ‘10’ (10b). This will cause all IDE outputs to
the IDE drive to drive low rather than the default tri-state (which is useful during boot up to
prevent any IDE drives from entering a test mode).
3. The IORDY Sample Point Enable bit of the IDE_TIM register for the appropriate IDE device
should then be set to ‘0’ to disable IORDY sampling by the ICH4-M. This ensures that zeros will
always be returned if the OS attempts to access the IDE device being swapped.
4. Power to the isolated power plane of the IDE device can then be removed and the system can
indicate to the user that the mobile swap bay can be removed and the IDE device replaced.
9.1.4.4.
Power Up Procedures After Device “Hot” Swap Completed
The procedures listed below summarize the steps that must be followed after a new IDE device has been
added to the mobile swap bay and the swap bay must be powered back up.
1. Once the IDE swap bay is replaced into the system, the power plane to the device should be
enabled once again.
2. The IORDY Sample Point Enable bit of the IDE_TIM register for the appropriate IDE device
should then be set to ‘1’ to enable IORDY sampling by the Intel 82801DBM ICH4-M. This
allows the OS to access the IDE device once again and waits for the assertion of IORDY in
response to an access request.
3. Once the system IDE interface is configured for normal operation once again, the reset signal to
the swap device should be de-asserted to allow the drive to initialize.
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9.2.
PCI
The Intel 82801DBM ICH4-M provides a PCI Bus interface that is compliant with the PCI Local Bus
Specification Revision 2.2. The implementation is optimized for high performance data streaming when
the ICH4-M is acting as either the target or the initiator in the PCI bus.
The ICH4-M supports six PCI Bus masters (excluding the ICH4-M), by providing six REQ#/GNT#
pairs. In addition, the ICH4-M supports two PC/PCI REQ#/GNT# pairs, one of which is multiplexed
with a PCI REQ#/GNT# pair.
Figure 99. PCI Bus Layout Example
1
2
Intel
ICH4-M
3
4
5
L1
6
L2
L3
L4
L5
L6
9.3.
AC’97
The Intel 82801DBM ICH4-M implements an AC’97 2.1, 2.2, and 2.3 compliant digital controller.
Please contact your codec IHV (Independent Hardware Vendor) for information on 2.2 compliant
products. The AC’97 2.2 specification is on the Intel website:
http://developer.intel.com/ial/scalableplatforms/audio/index.htm - 97spec/
The AC-link is a bi-directional, serial PCM digital stream. It handles multiple input and output data
streams, as well as control register accesses, employing a time division multiplexed (TDM) scheme. The
AC-link architecture provides for data transfer through individual frames transmitted in a serial fashion.
Each frame is divided into 12 outgoing and 12 incoming data streams, or slots. The architecture of the
ICH4-M AC-link allows a maximum of three codecs to be connected. Figure 100 shows a three-codec
topology of the AC-link for the ICH4-M.
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Figure 100. Intel 82801DBM ICH4-M AC’97 – Codec Connection
RESET#
Intel
ICH4-M
AC / MC / AMC
SDATA_OUT
SYNC
BIT_CLK
SDATA_IN0
SDATA_IN1
Primary
Codec
SDATA_IN2
AC / MC / AMC
Secondary
Codec
AC / MC / AMC
Tertiary
Codec
Note: If a modem codec is configured as the primary AC-link Codec, there should not be any Audio Codecs
residing on the AC-link. The primary codec may be connected to AC_SDIN0 as documented in the
Intel® 82801DBM I/O Controller Hub 4 Mobile Datasheet.
Clocking is provided from the primary codec on the link via AC_BIT_CLK, and is derived from a
24.576-MHz crystal or oscillator. Refer to the primary codec vendor for crystal or oscillator
requirements. AC_BIT_CLK is a 12.288 MHz clock driven by the primary codec to the digital
controller (ICH4-M) and to any other codec present. That clock is used as the time base for latching and
driving data. Clocking AC_BIT_CLK directly off the CK-408 clock chip’s 14.31818 MHz output is
not supported.
The ICH4-M supports wake-on-ring from S1M-S5 via the AC’97 link. The codec asserts AC_SDIN to
wake the system. To provide wake capability and/or caller ID, standby power must be provided to the
modem codec.
The ICH4-M has weak pull-down/pull-ups that are always enabled. This will keep the link from floating
when the AC-link is off or there are no codecs present.
If the Shut-off bit is not set, it implies that there is a codec on the link. Therefore, AC_BIT_CLK and
AC_SDOUT will be driven by the codec and the ICH4-M respectively. However, AC_SDIN0,
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AC_SDIN1, and AC_SDIN2 may not be driven. If the link is enabled, the assumption can be made that
there is at least one codec.
Figure 101. Intel 82801DBM ICH4-M AC’97 – AC_BIT_CLK Topology
Intel
ICH4-M
AC_BIT_CLK
L1
R1
L3
L3
R2
L4
L2
C
O
N
N
Primary
Codec
Table 48. AC’97 AC_BIT_CLK Routing Summary
AC’97 Routing Requirements
Maximum Trace Length
(inches)
Series Termination
Resistance
AC_BIT_CLK Signal
Length Matching
5 on 5
L1 = (1 to 8) – L3
R1 = 33
N/A
L2 = 0.1 to 6
R2 = Option 0 resistor
for debugging purposes
L3 = 0.1 to 0.4
- 47
L4 = (1 to 6) – L3
NOTES:
1. Simulations were performed using Analog Device’s* Codec (AD1885) and the Cirrus Logic’s* Codec (CS4205b).
Results showed that if the AD1885 codec was used a 33- resistor was best for R1 and if the CS4205b codec
was used a 47- resistor for R1 was best.
2. Bench data shows that a 47- resistor for R1 is best for the Sigmatel* 9750 codec.
Figure 102. Intel 82801DBM ICH4-M AC’97 – AC_SDOUT/AC_SYNC Topology
Intel
ICH4-M
AC_SDOUT
L2
L3
R2
L3
L1
C
O
N
N
R1
L4
190
Primary
Codec
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Table 49. AC’97 AC_SDOUT/AC_SYNC Routing Summary
AC’97 Routing Requirements
Maximum Trace Length
(inches)
Series Termination
Resistance
AC_SDOUT/AC_SYNC
Signal Length
Matching
5 on 5
L1 = (1 to 6) – L3
R1 = 33
N/A
L2 = 1 to 8
R2 = R1 if the connector
card that will be used
with the platform does
not have a series
termination on the card.
Otherwise R2 = 0
L3 = 0.1 to 0.4
L4 = (0.1 to 6) – L3
- 47
NOTES:
1. Simulations were performed using Analog Device’s* Codec (AD1885) and the Cirrus Logic’s* Codec (CS4205b).
Results showed that if the AD1885 codec was used a 33- resistor was best for R1 and if the CS4205b codec
was used a 47- resistor for R1 was best.
2. Bench data shows that a 47- resistor for R1 is best for the Sigmatel* 9750 codec.
Figure 103. Intel 82801DBM ICH4-M AC’97 – AC_SDIN Topology
Codec
Y5
R1
Intel
ICH4-M
Y1
Y2
AC_SDIN2
Y4
R2
Y3
AC_SDIN1
R2
Y3
AC_SDIN0
R2
CONN
Y1
AC97_SDATA_IN2
Y1
AC97_SDATA_IN1
Y1
AC97_SDATA_IN0
Table 50. AC’97 AC_SDIN Routing Summary
AC’97 Routing Requirements
Maximum Trace Length
(inches)
Series Termination
Resistance
AC_SDIN Signal
Length Matching
5 on 5
Y1 = 0.1 to 0.4
R1 = 33
N/A
Y2 = (1 to 8) – Y1
R2 = R1 if the connector
card that will be used
with the platform does
not have a series
termination on the card.
Otherwise R2 = 0
Y3 = (1 to 14) – Y1
Y4 = (1 to 6) – Y1
- 47
Y5 = (0.1 to 6) – Y1
NOTES:
1. Simulations were performed using Analog Device’s Codec (AD1885) and the Cirrus Logic’s Codec (CS4205b).
Results showed that if the AD1885 codec was used a 33- resistor was best for R1 and if the CS4205b codec
was used a 47- resistor for R1 was best.
2. Bench data shows that a 47- resistor for R1 is best for the Sigmatel 9750 codec.
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9.3.1.
AC’97 Routing
To ensure the maximum performance of the codec, proper component placement and routing techniques
are required. These techniques include properly isolating the codec, associated audio circuitry, analog
power supplies, and analog ground plane, from the rest of the motherboard. This includes plane splits
and proper routing of signals not associated with the audio section. Contact your vendor for devicespecific recommendations.
The basic recommendations are as follows:
Special consideration must be given for the ground return paths for the analog signals.
Digital signals routed in the vicinity of the analog audio signals must not cross the power plane
split lines. Analog and digital signals should be located as far as possible from each other.
Partition the board with all analog components grouped together in one area and all digital
components in another.
Separate analog and digital ground planes should be provided, with the digital components over the
digital ground plane, and the analog components, including the analog power regulators, over the
analog ground plane. The split between planes must be a minimum of 0.05 inches wide.
Keep digital signal traces, especially the clock, as far as possible from the analog input and voltage
reference pins.
Do not completely isolate the analog/audio ground plane from the rest of the board ground plane.
There should be a single point (0.25 inches to 0.5 inches wide) where the analog/isolated ground
plane connects to the main ground plane. The split between planes must be a minimum of 0.05
inches wide.
Any signals entering or leaving the analog area must cross the ground split in the area where the
analog ground is attached to the main motherboard ground. That is, no signal should cross the
split/gap between the ground planes, which would cause a ground loop, thereby greatly increasing
EMI emissions and degrading the analog and digital signal quality.
Analog power and signal traces should be routed over the analog ground plane.
Digital power and signal traces should be routed over the digital ground plane.
Bypassing and decoupling capacitors should be close to the IC pins, or positioned for the shortest
connections to pins, with wide traces to reduce impedance.
All resistors in the signal path or on the voltage reference should be metal film. Carbon resistors
can be used for DC voltages and the power supply path, where the voltage coefficient, temperature
coefficient, and noise are not factors.
Regions between analog signal traces should be filled with copper, which should be electrically
attached to the analog ground plane. Regions between digital signal traces should be filled with
copper, which should be electrically attached to the digital ground plane.
Locate the crystal or oscillator close to the codec.
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9.3.2.
Motherboard Implementation
The following design considerations are provided for the implementation of an Intel 82801DBM ICH4M platform using AC’97. These design guidelines have been developed to ensure maximum flexibility
for board designers, while reducing the risk of board-related issues. These recommendations are not the
only implementation or a complete checklist, but they are based on the ICH4-M platform.
Active components such as FET switches, buffers or logic states should not be implemented on the
AC-link signals, except for AC_RST#. Doing so would potentially interfere with timing margins
and signal integrity.
The ICH4-M supports wake-on-ring from S1M-S5 states via the AC’97 link. The codec asserts
AC_SDIN to wake the system. To provide wake capability and/or caller ID, standby power must be
provided to the modem codec. If no codec is attached to the link, internal pull-downs will prevent
the inputs from floating, so external resistors are not required.
PC_BEEP should be routed through the audio codec. Care should be taken to avoid the introduction
of a pop when powering the mixer up or down.
9.3.2.1.
Valid Codec Configurations
Table 51. Supported Codec Configurations
Option
Primary Codec
Secondary Codec
Tertiary Codec
Notes
1
Audio
Audio
Audio
1
2
Audio
Audio
Modem
1
3
Audio
Audio
Audio/Modem
1
4
Audio
Modem
Audio
1
5
Audio
Audio/Modem
Audio
1
6
Audio/Modem
Audio
Audio
1
NOTES:
1. For power management reasons, codec power management registers are in audio space. As a result, if there is
an audio codec in the system it must be Primary.
2. There cannot be two modems in a system since there is only one set of modem DMA channels.
3. The ICH4-M supports a codec on any of the AC_SDIN lines, however the modem codec ID must be either 00 or
01.
9.3.3.
SPKR Pin Configuration
SPKR is used as both the output signal to the system speaker and as a functional strap. The strap
function enables or disables the “TCO Timer Reboot function” based on the state of the SPKR pin on
the rising edge of PWROK. When enabled, the ICH4-M sends an SMI# to the processor upon a TCO
timer timeout. The status of this strap is readable via the NO_REBOOT bit (bit 1, D31: F0, Offset D4h).
The SPKR signal has a weak integrated pull-down resistor (the resistor is only enabled during
boot/reset). Therefore, its default state is a logical zero or set to reboot. To disable the feature, a jumper
can be populated to pull the signal line high (see Figure 104). The value of the pull-up must be such that
the voltage divider output caused by the pull-up, the effective pull-down (Reff), and the ICH4-M’s
integrated pull-down resistor will be read as logic high (0.5 * VCC3_3 to VCC3_3 + 0.5 V).
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Figure 104. Example Speaker Circuit
VCC3_3
R Value is
Implementation
Specific
Intel
ICH4-M
Integrated
Pull-down
SPKR
9KW - 50KW
Stuff Jumper to Disable
Timeout Feature
(No Reboot)
Effective Impedance
Due to Speaker and
Codec Circuit
Reff
9.4.
USB 2.0 Guidelines and Recommendations
9.4.1.
Layout Guidelines
9.4.1.1.
General Routing and Placement
Use the following general routing and placement guidelines when laying out a new design. These
guidelines will help to minimize signal quality and EMI problems. The USB 2.0 validation efforts
focused on a four-layer motherboard where the first layer is a signal layer, the second plane is power,
the third plane is ground and the fourth is a signal layer. This results in the placement of most of the
routing on the fourth plane (closest to the ground plane), allowing a higher component density on the
first plane.
1. Place the ICH4-M and major components on the un-routed board first. With minimum trace
lengths, route high-speed clock, periodic signals, and USB 2.0 differential pairs first. Maintain
maximum possible distance between high-speed clocks/periodic signals to USB 2.0 differential
pairs and any connector leaving the PCB (i.e. I/O connectors, control and signal headers, or power
connectors).
2. USB 2.0 signals should be ground referenced (on recommended stack-up this would be the
bottom signal layer).
3. Route USB 2.0 signals using a minimum of vias and corners. This reduces reflections and
impedance changes.
4. When it becomes necessary to turn 90°, use two 45° turns or an arc instead of making a single 90°
turn. This reduces reflections on the signal by minimizing impedance discontinuities. (As shown
in Figure 124.)
5. Do not route USB 2.0 traces under crystals, oscillators, clock synthesizers, magnetic devices or
ICs that use and/or duplicate clocks.
6. Stubs on high-speed USB signals should be avoided, as stubs will cause signal reflections and
affect signal quality. If a stub is unavoidable in the design, the sum of all stubs for a particular
signal line should not exceed 200 mils.
7. Route all traces over continuous planes (VCC or GND), with no interruptions. Avoid crossing
over anti-etch if at all possible. Crossing over anti-etch (plane splits) increases inductance and
radiation levels by forcing a greater loop area. Likewise, avoid changing layers with USB 2.0
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traces as much as practical. It is preferable to change layers to avoid crossing a plane split. Refer
to Section 9.4.2.
8. Separate signal traces into similar categories and route similar signal traces together (such as
routing differential pairs together).
9. Keep USB 2.0 USB signals clear of the core logic set. High current transients are produced during
internal state transitions and can be very difficult to filter out.
10. Follow the 20*h thumb rule by keeping traces at least 20*(height above the plane) away from the
edge of the plane (VCC or GND, depending on the plane the trace is over). For the suggested
stack-up the height above the plane is 4.5 mils. This calculates to a 90-mil spacing requirement
from the edge of the plane. This helps prevent the coupling of the signal onto adjacent wires and
also helps prevent free radiation of the signal from the edge of the PCB.
9.4.1.2.
USB 2.0 Trace Separation
Use the following separation guidelines.
1. Maintain parallelism between USB differential signals with the trace spacing needed to achieve
90- differential impedance. Deviations will normally occur due to package breakout and routing
to connector pins. Just ensure the amount and length of the deviations are kept to the minimum
possible.
2. Use an impedance calculator to determine the trace width and spacing required for the specific
board stack-up being used. 4-mil traces with 4.5-mil spacing results in approximately 90differential trace impedance.
3. Minimize the length of high-speed clock and periodic signal traces that run parallel to high-speed
USB signal lines, to minimize crosstalk. Based on EMI testing experience, the minimum
suggested spacing to clock signals is 50 mils.
4. Based on simulation data, use 20-mil minimum spacing between high-speed USB signal pairs and
other signal traces for optimal signal quality. This helps to prevent crosstalk.
Figure 105. Recommended USB Trace Spacing
Low-speed
non periodic
signal
DP1
20
9.4.1.3.
4
DM1
4.5
4
DP2
20
4
Distance in mils
Clock/Highspeed
periodic signal
DM2
4.5
4
50
USBRBIAS Connection
The USBRBIAS pin and the USBRBIAS# pin can be shorted and routed 5 on 5 to one end of a 22.6
±1% resistor to ground. Place the resistor within 500 mils of the Intel 82801DBM ICH4-M and avoid
routing next to clock pins.
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Figure 106. USBRBIAS Connection
Intel
ICH4-M
USBRBIAS
22.6Ω+/- 1%
USBRBIAS#
Table 52. USBRBIAS/USBRBIAS# Routing Summary
9.4.1.4.
USBRBIAS/ USBRBIAS#
Routing Requirements
Maximum Trace Length
Signal Length Matching
Signal Referencing
5 on 5
500 mils
N/A
N/A
USB 2.0 Termination
A common-mode choke should be used to terminate the USB 2.0 bus. Place the common-mode choke as
close as possible to the connector pins. See Section 9.4.4 for details.
9.4.1.5.
USB 2.0 Trace Length Pair Matching
USB 2.0 signal pair traces should be trace length matched. Max trace length mismatch between USB 2.0
signal pair should be no greater that 150 mils.
9.4.1.6.
USB 2.0 Trace Length Guidelines
Table 53. USB 2.0 Trace Length Guidelines (With Common-mode Choke)
Configuration
Back Panel
Signal
Referencing
Ground
Signal Matching
The max mismatch
between data pairs
should not be
greater than 150
mils
Motherboard
Trace Length
17 inches
Card Trace
Length
N/A
Maximum Total
Length
17 inches
NOTES:
1. These lengths are based upon simulation results and may be updated in the future.
2. All lengths are based upon using a common-mode choke (see Section 9.4.4.1 for details on common-mode
choke).
9.4.2.
Plane Splits, Voids, and Cut-Outs (Anti-Etch)
The following guidelines apply to the use of plane splits voids and cutouts.
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9.4.2.1.
VCC Plane Splits, Voids, and Cut-Outs (Anti-Etch)
Use the following guidelines for the VCC plane.
1. Traces should not cross anti-etch, for it greatly increases the return path for those signal traces.
This applies to USB 2.0 signals, high-speed clocks, and signal traces as well as slower signal
traces that might be coupling to them. USB signaling is not purely differential in all speeds (i.e.
the Full-speed Single Ended Zero is common mode).
2. Avoid routing of USB 2.0 signals 25 mils of any anti-etch to avoid coupling to the next split or
radiating from the edge of the PCB.
When breaking signals out from packages it is sometimes very difficult to avoid crossing plane splits or
changing signal layers, particularly in today’s motherboard environment that uses several different
voltage planes. Changing signal layers is preferable to crossing plane splits if a choice has to be made
between one or the other.
If crossing a plane split is completely unavoidable, proper placement of stitching caps can minimize the
adverse effects on EMI and signal quality performance caused by crossing the split. Stitching capacitors
are small-valued capacitors (1 F or lower in value) that bridge voltage plane splits close to where highspeed signals or clocks cross the plane split. The capacitor ends should tie to each plane separated by the
split. They are also used to bridge, or bypass, power and ground planes close to where a high-speed
signal changes layers. As an example of bridging plane splits, a plane split that separates VCC5 and
VCC3_3 planes should have a stitching cap placed near any high-speed signal crossing. One side of the
cap should tie to VCC5 and the other side should tie to VCC3_3. Stitching caps provide a high frequency
current return path across plane splits. They minimize the impedance discontinuity and current loop area
that crossing a plane split creates.
9.4.2.2.
GND Plane Splits, Voids, and Cut-Outs (Anti-Etch)
Avoid anti-etch on the GND plane.
9.4.3.
USB Power Line Layout Topology
The following is a suggested topology for power distribution of Vbus to USB ports. Circuits of this type
provide two types of protection during dynamic attach and detach situations on the bus: inrush current
limiting (droop) and dynamic detach fly-back protection. These two different situations require both
bulk capacitance (droop) and filtering capacitance (for dynamic detach fly-back voltage filtering). It is
important to minimize the inductance and resistance between the coupling capacitors and the USB ports.
That is, capacitors should be placed as close as possible to the port and the power carrying traces should
be as wide as possible, preferably, a plane. A good “rule-of-thumb” is to make the power carrying traces
wide enough that the system fuse will blow on an over current event. If the system fuse is rated at 1amps
then the power carrying traces should be wide enough to carry at least 1.5 amps.
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Figure 107. Good Downstream Power Connection
5V
5V Sus
5V
Switch
Thermister
Vcc
1
470pF
220uF
Gnd
Vcc
Port1
4
1
470pF
Gnd
9.4.4.
Port2
4
EMI Considerations
The following guidelines apply to the selection and placement of common-mode chokes and ESD
protection devices.
9.4.4.1.
Common Mode Chokes
Testing has shown that common-mode chokes can provide required noise attenuation. A design should
include a common-mode choke footprint to provide a stuffing option in the event the choke is needed to
pass EMI testing. Figure 108 shows the schematic of a typical common-mode choke and ESD
suppression components. The choke should be placed as close as possible to the USB connector signal
pins.
Figure 108. Common Mode Choke Schematic
Vcc
D+
Common Mode
Choke
USB A
Connector
D ESD Supression
Components
Common mode chokes distort full-speed and high-speed signal quality. As the common mode
impedance increases, the distortion will increase, so you should test the effects of the common mode
choke on full speed and high-speed signal quality. Common mode chokes with a target impedance of 80
to 90 at 100 MHz generally provide adequate noise attenuation.
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Finding a common mode choke that meets the designer’s needs is a two-step process.
1. A part must be chosen with the impedance value that provides the required noise attenuation. This
is a function of the electrical and mechanical characteristics of the part chosen and the frequency
and strength of the noise present on the USB traces that you are trying to suppress.
2. Once you have a part that gives passing EMI results the second step is to test the effect this part
has on signal quality. Higher impedance common-mode chokes generally have a greater damaging
effect on signal quality, so care must be used when increasing the impedance without doing
thorough testing. Thorough testing means that the signal quality must be checked for low-speed,
full-speed and high-speed USB operation.
9.4.5.
ESD
Classic USB (1.0/1.1) provided ESD suppression using in line ferrites and capacitors that formed a low
pass filter. This technique doesn’t work for USB 2.0 due to the much higher signal rate of high-speed
data. A device that has been tested successfully is based on spark gap technology. Proper placement of
any ESD protection device is on the data lines between the common-mode choke and the USB
connector data pins as shown in Figure 108. Other types of low-capacitance ESD protection devices
may work as well but were not investigated. As with the common mode choke solution, Intel
recommends including footprints for some type of ESD protection device as a stuffing option in case it
is needed to pass ESD testing.
9.5.
I/O APIC (I/O Advanced Programmable Interrupt
Controller)
The Intel 82801DBM ICH4-M is designed to be backwards compatible with a number of the legacy
interrupt handling mechanisms as well as to be compliant with the latest I/O (x) APIC architecture. In
addition to implementing two 8259 interrupt controllers (PIC), the ICH4-M also incorporates an
Advanced Programmable Interrupt Controller (APIC) that is implemented via the 3-wire serial APIC
bus that connects all I/O and local APICs. An advancement in the interrupt delivery and control
architecture of the ICH4-M is represented by support for the I/O (x) APIC specification where PCI
devices deliver interrupts as write cycles that are written directly to a register that represents the desired
interrupt. These are ultimately delivered via the serial APIC bus or FSB. Furthermore, on Intel Pentium
M/Intel Celeron M processor-based systems, the ICH4-M has the option to let the integrated I/O APIC
behave as an I/O (x) APIC. This allows the ICH4-M to deliver interrupts in a parallel manner rather than
just a serial one. This is accomplished by I/O APIC writes to a region of memory that is snooped by the
processor and thereby knows what interrupt goes active.
On Intel Pentium M/Intel Celeron M processor-based platforms, the serial I/O APIC bus interface of the
ICH4-M should be disabled. I/O (x) APIC is supported on the platform and the servicing of interrupts is
accomplished via a FSB interrupt delivery mechanism.
The serial I/O APIC bus interface of the ICH4-M should be disabled as follows.
Tie APICCLK directly to ground.
Tie APICD0, APICD1 to ground through a 10-k
using XOR chain testing)
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The Intel® Pentium® M Processor / Intel® Celeron® M Processor does not have pins dedicated for a
serial I/O APIC bus interface and thus, no hardware change is necessary. However, it is strongly
encouraged to enable I/O APIC support in the BIOS and operating system on the processor based
systems rather than the legacy 8259 interrupt controller due to the performance benefits and efficiencies
that the I/O (x) APIC architecture enjoys over the older PIC architecture.
9.6.
SMBus 2.0/SMLink Interface
The SMBus interface on the Intel 82801DBM ICH4-M uses two signals SMBCLK and SMBDATA to
send and receive data from components residing on the bus. These signals are used exclusively by the
SMBus Host Controller. The SMBus Host Controller resides inside the ICH4-M.
The ICH4-M incorporates an SMLink interface supporting Alert-on-LAN*, Alert-on-LAN2*, and a
slave functionality. It uses two signals SMLINK[1:0]. SMLINK[0] corresponds to an SMBus clock
signal and SMLINK[1] corresponds to an SMBus data signal. These signals are part of the SMB Slave
Interface.
For Alert-on-LAN* functionality, the ICH4-M transmits heartbeat and event messages over the
interface. When using the Intel® 82562EM Platform LAN Connect Component, the ICH4-M’s
integrated LAN Controller will claim the SMLink heartbeat and event messages and send them out over
the network. An external, Alert-on-LAN2*-enabled LAN Controller (i.e. Intel 82562EM 10/100 Mbps
Platform LAN Connect) will connect to the SMLink signals to receive heartbeat and event messages, as
well as access the ICH4-M SMBus Slave Interface. The slave interface function allows an external
micro-controller to perform various functions. For example, the slave write interface can reset or wake
a system, generate SMI# or interrupts, and send a message. The slave read interface can read the system
power state, read the watchdog timer status, and read system status bits.
Both the SMBus Host Controller and the SMBus Slave Interface obey the SMBus 1.0 protocol, so the
two interfaces can be externally wire-OR’ed together to allow an external management ASIC (such as
Intel 82562EM 10/100 Mbps Platform LAN Connect) to access targets on the SMBus as well as the
ICH4-M Slave Interface. Additionally, the ICH4-M supports slave functionality, including the Host
Notify protocol, on the SMLink pins. Therefore, in order to be fully compliant with the SMBus 2.0
specification (which requires the Host Notify cycle), the SMLink and SMBus signals must be tied
together externally. This is done by connecting SMLink[0] to SMBCLK and SMLink[1] to SMBDATA.
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Figure 109. SMBUS 2.0/SMLink Protocol
SPD Data
Host Controller and
Slave Interface
SMBus
Temperature on
Thermal Sensor
Network
Interface Card
on PCI Bus
SMBCLK
Microcontroller
SMBDATA
Intel
ICH4-M
SMLink
SMLink0
SMLink1
Wire OR
(optional)
Motherboard
LAN
Controller
SMbus-SMlink_IF
Note: Intel does not support external access of the ICH4-M’s Integrated LAN Controller via the SMLink
interface. Also, Intel does not support access of the ICH4-M’s SMBus Slave Interface by the ICH4-M’s
SMBus Host Controller. Refer to the Intel® 82801DBM I/O Controller Hub 4 Mobile (ICH4-M)
Datasheet functionality descriptions of the SMLink and SMBus interface.
9.6.1.
SMBus Architecture and Design Considerations
9.6.1.1.
SMBus Design Considerations
There is not a single SMBus design solution that will work for all platforms. One must consider the total
bus capacitance and device capabilities when designing SMBus segments. Routing SMBus to the PCI
slots makes the design process even more challenging since they add so much capacitance to the bus.
This extra capacitance has a large affect on the bus time constant which in turn affects the bus rise and
fall times.
Primary considerations in the design process are:
1. Device class (High/Low power). Most designs use primarily high power devices.
2. Are there devices that must run in S3?
3. Amount of VCC_SUSPEND current available, i.e. minimizing load of VCC_ SUSPEND.
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9.6.1.2.
General Design Issues/Notes
Regardless of the architecture used, there are some general considerations.
1. The pull-up resistor size for the SMBus data and clock signals is dependent on the bus load (this
includes all device leakage currents). Generally the SMBus device that can sink the least amount
of current is the limiting agent on how small the resistor can be. The pull-up resistor cannot be
made so large that the bus time constant (Resistance X Capacitance) does not meet the SMBus
rise and fall time specification.
2. The maximum bus capacitance that a physical segment can reach is 400 pF.
3. The Intel ICH4-M does not run SMBus cycles while in S3.
4. SMBus devices that can operate in S3 must be powered by the VCC_ SUSPEND supply.
9.6.1.3.
High Power/Low Power Mixed Architecture
This design allows for current isolation of high and low current devices while also allowing SMBus
devices to communicate during the S3 state. VCC_SUSPEND leakage is minimized by keeping non-essential
devices on the core supply. This is accomplished by the use of a “FET” to isolate the devices powered
by the core and suspend supplies. See Figure 110.
Figure 110. High Power/Low Power Mixed VCC_SUSPEND/VCC_CORE Architecture
Non- Standby devices
-
Vcc
Vcc
Devices running in Standby
Devices running in Standby
VccSus3_3 VccSus
Current Isolation
Logic
SMBus
Buffered Power Good Signal From
Power Supply
Low
Current
- devices
Non Standby
VccSus VccSus3_3
SMBus
Vcc
Vcc
SMBus
Buffered Power Good Signal From
Power Supply
ICH4
High
Current
Added Considerations for mixed architecture:
1. The bus switch must be powered by VCC_SUSPEND.
2. Devices that are powered by the VCC_ SUSPEND well must not drive into other devices that are
powered off. This is accomplished with the “bus switch.”
3. The bus bridge can be a device like the Phillips PCA9515.
9.6.1.4.
Calculating the Physical Segment Pull-Up Resistor
The following tables are provided as a reference for calculating the value of the pull-up resistor that may
be used for a physical bus segment. If any physical bus segment exceeds 400 pF, then a bus bridge
device like the Phillips* PCA9515 must be used to separate the physical segment into two segments that
individually have a bus capacitance less than 400 pF.
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Table 54. Bus Capacitance Reference Chart
Device
# of Devices/
Trace Length
Capacitance Includes
Cap (pF)
ICH4-M
1
Pin Capacitance
12
CK408
1
Pin Capacitance
10
SODIMMS
2
Pin Capacitance (10 pF) + 1 inch worth of trace capacitance (2 pF/inch)
per SO-DIMM and 2 pF connector capacitance per SO-DIMM
28
PCI
Slots
2
Bus
Trace
Length
in inches
3
Each PCI add-in card is allowed up to 40 pF + 3 pF per each connector
42
86
3
129
4
172
5
215
6
258
≥24
2 pF per inch of trace length
48
≥36
72
≥48
96
Table 55. Bus Capacitance/Pull-Up Resistor Relationship
Physical Bus Segment Capacitance
Pull-Up Range (For Vcc = 3.3 V
0 to 100 pF
8.2 k
to 1.2 k
100 to 200 pF
4.7 k
to 1.2 k
200 to 300 pF
3.3 k
to 1.2 k
300 to 400 pF
2.2 k
to 1.2 k
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9.7.
FWH
The following provides general guidelines for compatibility and design recommendations for supporting
the FWH device. The majority of the changes will be incorporated in the BIOS. Refer to the Intel®
82802AB/82802AC Firmware Hub (FWH) Datasheet or equivalent.
9.7.1.
FWH Decoupling
A 0.1-µF capacitor should be placed between the VCC supply pins and the VSS ground pins to decouple
high frequency noise, which may affect the programmability of the device. Additionally, a 4.7-µF
capacitor should be placed between the VCC supply pins and the VSS ground pins to decouple low
frequency noise. The capacitors should be placed no further than 390 mils from the VCC supply pins.
9.7.2.
In Circuit FWH Programming
All cycles destined for the FWH will appear on PCI. The Intel 82801DBM ICH4-M hub interface to PCI
Bridge will put all CPU boot cycles out on PCI (before sending them out on the FWH interface). If the
ICH4-M is set for subtractive decode, these boot cycles can be accepted by a positive decode agent on
the PCI bus. This enables the ability to boot from a PCI card that positively decodes these memory
cycles. In order to boot from a PCI card, it is necessary to keep the ICH4-M in subtractive decode mode.
If a PCI boot card is inserted and the ICH4-M is programmed for positive decode, there will be two
devices positively decoding the same cycle.
9.7.3.
FWH INIT# Voltage Compatibility
The FWH INIT# signal trip points need to be considered because they are NOT consistent among
different FWH manufacturers. The INIT# signal is active low. Therefore, the inactive state of the Intel
82801DBM ICH4-M INIT# signal needs to be at a value slightly higher than the VIH min FWH INIT#
pin specification. The inactive state of this signal is typically governed by the formula V_CPU_IO(min)
– noise margin. Therefore, if the V_CPU_IO(min) of the processor is 1.60 V, the noise margin is 200
mV and the VIH min spec of the FWH INIT# input signal is 1.35 V, there would be no compatibility
issue because 1.6 V – 0.2 V = 1.40 V which is greater than the 1.35 V minimum of the FWH. If the VIH
min of the FWH was 1.45 V, then there would be an incompatibility and logic translation would need to
be used. The examples above do not take into account any noise that may be encountered on the INIT#
signal. Care must be taken to ensure that the VIH min specification is met with ample noise margin. In
applications where it is necessary to use translation logic, refer to Section 4.1.4.1.7.
The solution assumes that level translation is necessary. Figure 23 in Section 4.1.4.1.7 implements a
solution for the ICH4-M FWH signal INIT#. Trace lengths and resistor values can be found in Table 14.
The Voltage Translator circuitry is shown in Figure 24. It is strongly recommended that any system that
implements a FWH should have its INIT# input connected to the ICH4-M.
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9.7.4.
FWH VPP Design Guidelines
The VPP pin on the FWH is used for programming the flash cells. The FWH supports VPP of 3.3 V or 12
V. If VPP is 12 V, the flash cells will program about 50% faster than at 3.3 V. However, the FWH only
supports 12-V VPP for 80 hours (3.3 V on Vpp does not affect the life of the device). The 12-V VPP
would be useful in a programmer environment, which is typically an event that occurs very infrequently
(much less than 80 hours). The VPP pin MUST be tied to 3.3 V on the motherboard.
In some instances, it is desirable to program the FWH during assembly with the device soldered down
on the board. In order to decrease programming time it becomes necessary to apply 12 V to the VPP pin.
The following circuit will allow testers to put 12 V on the VPP pin while keeping this voltage separated
from the 3.3-V plane to which the rest of the power pins are connected. This circuit also allows the
board to operate with 3.3 V on this pin during normal operation.
Figure 111. FWH VPP Isolation Circuitry
3.3V
12V (From Motherboard)
1K
FET
VPP
9.7.5.
FWH INIT# Assertion/Deassertion Timings
Due to the large routing solution space and necessity of a voltage translator in the design of a FWH on
Intel® Pentium® M Processor / Intel® Celeron® M Processor and Intel 82801DBM ICH4-M based
platforms, the following timing requirements must be met to ensure proper system operation.
For INIT# assertion timings, a conservative analysis of the worst case signal propagation times shows
that no timing concerns exist because the ICH4-M asserts INIT# for 16 PCI clocks (485 ns) before
deasserting. This provides adequate time for INIT# to propagate to both the processor and FWH.
For the INIT# deassertion event, the critical timing is the minimum period of time before the processor
is ready to begin fetching code from the FWH after the INIT# based reset begins. This minimum period
is conservatively set at 1 CPU clock (10 ns). This also represents the maximum allowed propagation
time for the INIT# signal from the ICH4-M to the FWH.
Systems that use alternative devices (i.e. not a FWH) to store the firmware may or may not require the
use of INIT#. If INIT# is not used, an analysis should be done to ensure there is no negative impact to
system operation. If INIT# is implemented on such a device, voltage translation may be necessary, and
the assertion/deassertion timings noted above still apply.
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9.8.
RTC
The Intel 82801DBM ICH4-M contains a real time clock (RTC) with 256 bytes of battery backed
SRAM. The internal RTC module provides two key functions: keeping date and time and storing system
data in its RAM when the system is powered down.
The ICH4-M uses a crystal circuit to generate a low-swing, 32 -kHz input sine wave. This input is
amplified and driven back to the crystal circuit via the RTCX2 signal. Internal to the ICH4-M, the
RTCX1 signal is amplified to drive internal logic as well as generate a free running full swing clock
output for system use. This output ball of the ICH4-M is called SUSCLK. This is illustrated in Figure
112.
Figure 112. RTCX1 and SUSCLK Relationship in Intel 82801DBM ICH4-M
Low-Swing 32.768 kHz
Sine Wave Source
RTCX1
Internal
Oscillator
Full-Swing 32.768 kHz
Output Signal
Intel
ICH4-M
SUSCLK
For further information on the RTC, please consult Application Note AP-728 ICH Family Real Time
Clock (RTC) Accuracy and Considerations Under Test Conditions. This application note is valid for the
ICH4-M.
Even if the ICH4-M internal RTC is not used, it is still necessary to supply a clock input to RTCX1 of
the ICH4-M because other signals are gated off that clock in suspend modes. However, in this case, the
frequency accuracy (32.768 kHz) of the clock inputs is not critical; a cheap crystal can be used or a
single clock input can be driven into RTCX1with RTCX2 left as no connect. Figure 113 illustrates the
connection.
Note: This is not a validated feature on the ICH4-M. The peak-to-peak swing on RTCX1 cannot exceed 1.0 V.
Figure 113. External Circuitry for Intel 82801DBM ICH4-M Where the Internal RTC is Not Used
RTCX1
32 KHz
206
5M
RTCX2
Internal
External
No Connection
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9.8.1.
RTC Crystal
The Intel 82801DBM ICH4-M RTC module requires an external oscillating source of 32.768 kHz
connected on the RTCX1 and RTCX2 balls. Figure 114 documents the external circuitry that comprises
the oscillator of the ICH4-M RTC.
Figure 114. External Circuitry for the Intel 82801DBM ICH4-M RTC
VCCRTC
3.3V Sus
1uF
RTCX2
1kΩ
R1
10MΩ
32.768 kHz
Xtal
Vbatt
RTCX1
C3
0.047uF
C1
18pF
R2
10MΩ
C2
18pF
VBIAS
VBIAS, VCCRTC, RTCX1, and RTCX2 are ICH4 pins
VBIAS is used to bias the ICH4 Internal Oscillator
VCCRTC powers the RTC well of the ICH4
RTCX1 is the Input to the Internal Oscillator
RTCX2 is the feedback for the external crystal
Notes
Reference Designators Arbitrarily Assigned
3.3V Sus is Active Whenever System Plugged In
Vbatt is Voltage Provided By Battery
NOTES:
1. The exact capacitor value needs to be based on what the crystal maker recommends. (Typical values for C1 and
C2 are 18 pF, based on crystal load of 12.5 pF.)
2. VCCRTC: Power for RTC Well
3. RTCX2: Crystal Input 2 – Connected to the 32.7 68 kHz crystal
4. RTCX1: Crystal Input 1 – Connected to the 32.7 68 kHz crystal
5. VBIAS: RTC BIAS Voltage – This ball is used to provide a reference voltage, and this DC voltage sets a current,
which is mirrored throughout the oscillator and buffer circuitry.
6. VSS: Ground
Table 56. RTC Routing Summary
RTC Routing
Requirements
Maximum Trace
Length To Crystal
Signal
Length
Matching
R1, R2, C1, and C2
tolerances
Signal
Referencing
5 mil trace width
(results in ~2 pF per
inch)
1 inch
NA
R1 = R2 = 10 M
Ground
± 5%
C1 = C2 = (NPO class)
See Section 9.8.2 for
calculating a specific
capacitance value for C1
and C2
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9.8.2.
External Capacitors
To maintain the RTC accuracy, the external capacitor C3 needs to be 0.047 µF and capacitor values C1
and C2 should be chosen to provide the manufacturer’s specified load capacitance (Cload) for the crystal
when combined with the parasitic capacitance of the trace, socket (if used), and package. The following
equation can be used to choose the external capacitance values:
Cload = [(C1 + Cin1 + Ctrace1)*(C2 + Cin2 + Ctrace2)]/[(C1 + Cin1 + Ctrace1 + C2 + Cin2 + Ctrace2)] + Cparasitic
Where:
Cload = Crystal’s load capacitance. This value can be obtained from Crystal’s specification.
Cin1, Cin2 = input capacitances at RTCX1, RTCX2 balls of the ICH4-M. These values can be
obtained in the Intel® 82801DBM I/O Controller Hub 4 Mobile (ICH4-M) Datasheet.
Ctrace1, Ctrace2 = Trace length capacitances measured from Crystal terminals to RTCX1, RTCX2
balls. These values depend on the characteristics of board material, the width of signal traces and
the length of the traces. A typical value, based on a 5 mil wide trace and a ½ ounce copper pour, is
approximately equal to :
Ctrace = trace length * 2 pF/inch
Cparasitic = Crystal’s parasitic capacitance. This capacitance is created by the existence of 2
electrode plates and the dielectric constant of the crystal blank inside the Crystal part. Refer to the
crystal’s specification to obtain this value.
Ideally, C1, C2 can be chosen such that C1 = C2. Using the equation of Cload above, the value of C1, C2
can be calculated to give the best accuracy (closest to 32.768 kHz) of the RTC circuit at room
temperature. However, C2 can be chosen such that C2 > C1. Then C1 can be trimmed to obtain the
32.768 kHz.
In certain conditions, both C1, C2 values can be shifted away from the theoretical values (calculated
values from the above equation) to obtain the closest oscillation frequency to 32.768 kHz. When C1, C2
values are smaller then the theoretical values, the RTC oscillation frequency will be higher.
The following example will illustrates the use of the practical values C1, C2 in the case that theoretical
values cannot guarantee the accuracy of the RTC in low temperature condition:
Example 1:
According to a required 12-pF load capacitance of a typical crystal that is used with the ICH4-M, the
calculated values of C1 = C2 is 10 pF at room temperature (25°C) to yield a 32.768 kHz oscillation.
At 0°C the frequency stability of crystal gives – 23 ppm (assumed that the circuit has 0 ppm at 25°C).
This makes the RTC circuit oscillate at 32.767246 kHz instead of 32.768 kHz.
If the values of C1, C2 are chosen to be 6.8 pF instead of 10 pF, the RTC will oscillate at a higher
frequency at room temperature (+23 ppm) but this configuration of C1 / C2 makes the circuit oscillate
closer to 32.768 kHz at 0°C. The 6.8-pF value of C1 and 2 is the practical value.
Note that the temperature dependency of crystal frequency is a parabolic relationship (ppm / degree
square). The effect of changing the crystal’s frequency when operating at 0°C (25°C below room
temperature) is the same when operating at 50°C (25°C above room temperature).
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9.8.3.
RTC Layout Considerations
Since the RTC circuit is very sensitive and requires high accuracy oscillation, reasonable care must be
taken during layout and routing of the RTC circuit. Some recommendations are:
1. Reduce trace capacitance by minimizing the RTC trace length. The Intel 82801DBM ICH4-M
requires a trace length less than 1 inch on each branch (from crystal’s terminal to RTCXn ball).
Routing the RTC circuit should be kept simple to simplify the trace length measurement and
increase accuracy on calculating trace capacitances. Trace capacitance depends on the trace width
and dielectric constant of the board’s material. On FR-4, a 5-mil trace has approximately 2 pF per
inch.
2. Trace signal coupling must be limited as much as possible by avoiding the routing of adjacent PCI
signals close to RTCX1, RTCX2, and VBIAS.
3. Ground guard plane is highly recommended.
4. The oscillator VCC should be clean; use a filter, such as an RC low-pass, or a ferrite inductor.
9.8.4.
RTC External Battery Connections
The RTC requires an external battery connection to maintain its functionality and its RAM while the
Intel 82801DBM ICH4-M is not powered by the system.
Example batteries are: Duracell* 2032, 2025, or 2016 (or equivalent), which can give many years of
operation. Batteries are rated by storage capacity. The battery life can be calculated by dividing the
capacity by the average current required. For example, if the battery storage capacity is 170 mAh
(assumed usable) and the average current required is 5 µA, the battery life will be at least:
170,000 µAh / 5 µA = 34,000 h = 3.9 years
The voltage of the battery can affect the RTC accuracy. In general, when the battery voltage decays, the
RTC accuracy also decreases. High accuracy can be obtained when the RTC voltage is in the range of
3.0 V to 3.3 V.
The battery must be connected to the ICH4-M via a Schottky diode circuit for isolation. The Schottky
diode circuit allows the ICH4-M RTC-well to be powered by the battery when the system power is not
available, but by the system power when it is available. To do this, the diodes are set to be reverse
biased when the system power is not available. Figure 115 is an example of a diode circuit that is used.
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Figure 115. Diode Circuit to Connect RTC External Battery
VCCSUS3_3
VccRTC
1.0uF
1K
A standby power supply should be used in a mobile system to provide continuous power to the RTC
when available, which will significantly increase the RTC battery life and thereby the RTC accuracy.
9.8.5.
RTC External RTCRST# Circuit
Figure 116. RTCRST# External Circuit for the ICH4-M RTC
VCCSUS3_3
DIODE/
BATTERY
CIRCUIT
VccRTC
1.0uF
1K
180K
RTCRST #
0.1uF
RTCRST#
CIRCUIT
The Intel 82801DBM ICH4-M RTC requires some additional external circuitry. The RTCRST# signal is
used to reset the RTC well. The external capacitor and the external resistor between RTCRST# and the
RTC battery (VBAT) were selected to create an RC time delay, such that RTCRST# will go high some
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time after the battery voltage is valid. The RC time delay should be in the range of 18 ms - 25 ms. Any
resistor and capacitor combination that yields the proper time constant is acceptable. When RTCRST# is
asserted, bit 2 (RTC_PWR_STS) in the GEN_PMCON_3 (General PM Configuration 3) register is set
to 1, and remains set until software clears it. As a result of this, when the system boots, the BIOS knows
that the RTC battery has been removed.
This RTCRST# circuit is combined with the diode circuit (shown in Figure 115) whose purpose is to
allow the RTC well to be powered by the battery when the system power is not available. Figure 116 is
an example of this circuitry that is used in conjunction with the external diode circuit.
9.8.6.
VBIAS DC Voltage and Noise Measurements
VBIAS is a DC voltage level that is necessary for biasing the RTC oscillator circuit. This DC voltage
level is filtered out from the RTC oscillation signal by the RC network of R2 and C3 (see Figure 114).
Therefore, it is a self-adjusting voltage. Board designers should not manually bias the voltage level on
VBIAS. Checking VBIAS level is used for testing purposes only to determine the right bias condition of
the RTC circuit.
VBIAS should be at least 200 mV DC. The RC network of R2 and C3 will filter out most of AC signal
noise that exists on this ball. However, the noise on this ball should be kept minimal in order to
guarantee the stability of the RTC oscillation.
Probing VBIAS requires the same technique as probing the RTCX1, RTCX2 signals (using Op-Amp).
See Application Note AP-728 for further details on measuring techniques.
Note that VBIAS is also very sensitive to environmental conditions.
9.8.7.
SUSCLK
SUSCLK is a square waveform signal output from the RTC oscillation circuit. Depending on the
quality of the oscillation signal on RTCX1 (largest voltage swing), SUSCLK duty cycle can be between
30-70%. If the SUSCLK duty cycle is beyond 30-70% range, it indicates a poor oscillation signal on
RTCX1 and RTCX2.
SUSCLK can be probed directly using normal probe (50- input impedance probe) and it is an
appropriated signal to check the RTC frequency to determine the accuracy of the ICH4-M’s RTC Clock
(see Application Note AP-728 for further details).
9.8.8.
RTC-Well Input Strap Requirements
All RTC-well inputs (RSMRST#, RTCRST#, INTRUDER#) must be either pulled up to VCCRTC or
pulled-down to ground while in the G3 state. RTCRST# when configured as shown in Figure 116 meets
this requirement. RSMRST# should have a weak external pull-down to ground and INTRUDER#
should have a weak external pull-up to VCCRTC. This will prevent these nodes from floating in G3, and
correspondingly will prevent ICCRTC leakage that can cause excessive coin-cell drain. The PWROK
input signal should also be configured with an external weak pull-down.
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9.9.
Internal LAN Layout Guidelines
The Intel 82801DBM ICH4-M provides several options for LAN capability. The platform supports
several components depending upon the target market. Available LAN components include the Intel®
82540EP Gigabit Ethernet Controller, Intel® 82551QM Fast Ethernet Controller, Intel® 82562ET, and
Intel® 82562EM Platform LAN Connect components.
Table 57. LAN Component Connections/Features
LAN Component
Interface to
ICH4-M
Connection
Features
Intel 82540EP (196 BGA)
PCI
Gigabit Ethernet
(1000BASE-T) with
Alert Standard Format
(ASF) alerting
Gigabit Ethernet, ASF 1.0
alerting, PCI 2.2 compatible
Intel 82551QM (196 BGA)
PCI
Performance 10/100
Ethernet with ASF
alerting
Ethernet 10/100 connection,
ASF 1.0 alerting, PCI 2.2
compatible
Intel 82562EM (48 Pin SSOP)
LCI
Advanced 10/100
Ethernet
Ethernet 10/100 connection,
Alert on LAN* (AoL)
Intel 82562ET (48 Pin SSOP)
LCI
Basic 10/100 Ethernet
Ethernet 10/100 connection
Design guidelines are provided for each required interface and connection.
9.9.1.
Footprint Compatibility
The Intel 82540EP Gigabit Ethernet Controller and the Intel 82551QM Fast Ethernet Controller are all
manufactured in a footprint compatible 15 mm x 15 mm (1-mm pitch), 196-ball grid array package.
Many of the critical signal pin locations on the 82540EP and the 82551QM are identical, allowing
designers to create a single design that accommodates any one of these parts. Because the usage of some
pins on the 82540EP differ from the usage on the 82551QM, the parts are not referred to as “pin
compatible.” The term “footprint compatible” refers to the fact that the parts share the same package
size, same number and pattern of pins, and layout of signals that allow for the flexible, cost effective,
multipurpose design.
Design guidelines are provided for each required interface and connection. Refer to the following
figures and the subsequent table for the corresponding section of this design guide.
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Figure 117. Intel 82801DBM ICH4-M/Platform LAN Connect Section
A
Intel
ICH4-M
B
82562EM/
82562ET
Magnetic
Module
82551QM
Connector
PCI
82540EP
Refer to the PCI
Specification
Refer to the selected Intel
LAN component
C
Table 58. LAN Design Guide Section Reference
Layout Section
Figure 117 Reference
Intel ICH4-M – LAN Connect Interface (LCI)
A
Reference Section 9.9.2
Intel 82562ET / Intel 82562EM
B
Reference Section 9.9.3
Intel 82551QM / Intel 82540EP
C
Reference Section 9.9.5
®
®
®
9.9.2.
Design Guide Section
Intel 82801DBM ICH4-M – LAN Connect Interface Guidelines
This section contains guidelines on how to implement a platform LAN Connect device on a system
motherboard. It should not be treated as a specification and the system designer must ensure through
simulations or other techniques that the system meets the specified timings. Special care must be given
to matching the LAN_CLK traces to those of the other signals, as shown below. The following are
guidelines for the Intel 82801DBM ICH4-M to LAN Connect Interface. The following signal lines are
used on this interface:
LAN_CLK
LAN_RSTSYNC
LAN_RXD[2:0]
LAN_TXD[2:0]
This interface supports Intel 82562ET and Intel 82562EM components. Signal lines LAN_CLK,
LAN_RSTSYNC, LAN_RXD[0], and LAN_TXD[0] are shared by all components.
9.9.2.1.
Bus Topologies
The Platform LAN Connect Interface can be configured in several topologies:
Direct point-to-point connection between the ICH4-M and the LAN component
LOM Implementation
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9.9.2.1.1.
LOM (LAN On Motherboard) Point-To-Point Interconnect
The following are guidelines for a single solution motherboard. Either Intel 82562EM or Intel 82562ET
are uniquely installed.
Figure 118. Single Solution Interconnect
L
LAN_CLK
Intel
ICH4-M
LAN_RSTSYNC
LAN_RXD[2:0]
Platform
LAN
Connect
(PLC)
LAN_TXD[2:0]
Table 59. LAN LOM Routing Summary
9.9.2.2.
Trace Impedance
LAN Routing
Requirements
Maximum Trace
Length
Signal
Referencing
LAN Signal Length Matching
55
5 on 10
4.5 to 12 inches
Ground
Data signals must be equal to
or no more than 0.5 inches
(500 mils) shorter than the
LAN clock trace.
± 15%
Signal Routing and Layout
Platform LAN Connect Interface signals must be carefully routed on the motherboard to meet the timing
and signal quality requirements of this interface specification. The following are some general
guidelines that should be followed. Intel recommends that the board designer simulate the board routing
to verify that the specifications are met for flight times and skews due to trace mismatch and crosstalk.
On the motherboard the length of each data trace is either equal in length to the LAN_CLK trace or up
to 0.5 inches shorter than the LAN_CLK trace. (LAN_CLK should always be the longest motherboard
trace in each group.)
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Figure 119. LAN_CLK Routing Example
LAN_CLK
LAN_RXD0
9.9.2.3.
Crosstalk Consideration
Noise due to crosstalk must be carefully controlled to a minimum. Crosstalk is the key cause of timing
skews and is the largest part of the tRMATCH skew parameter. tRMATCH is the sum of the trace length
mismatch between LAN_CLK and the LAN data signals. To meet this requirement on the board, the
length of each data trace is either equal to or up to 0.5 inches shorter than the LAN_CLK trace.
Maintaining at least 100 mils of spacing should minimize noise due to crosstalk from non-PLC signals.
9.9.2.4.
Impedances
The motherboard impedances should be controlled to minimize the impact of any mismatch between the
motherboard. An impedance of 55 ± 15% is strongly recommended; otherwise, signal integrity
requirements may be violated.
9.9.2.5.
Line Termination
Line termination mechanisms are not specified for the LAN Connect Interface. Slew rate controlled
output buffers achieve acceptable signal integrity by controlling signal reflection, over/undershoot, and
ringback. A 0- to 33- series resistor can be installed at the driver side of the interface should the
developer have concerns about over/undershoot. Note that the receiver must allow for any drive
strength and board impedance characteristic within the specified ranges.
9.9.2.6.
Terminating Unused LAN Connect Interface Signals
The LAN Connect Interface on the ICH4-M can be left as a no-connect if it is not used.
9.9.3.
Intel 82562ET / Intel 82562 EM Guidelines
For correct LAN performance, designers must follow the general guidelines outlined in Section 9.9.6.
Additional guidelines for implementing an Intel 82562ET or Intel 82562EM Platform LAN Connect
component are provided below.
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9.9.3.1.
Guidelines for Intel 82562ET / Intel 82562EM Component Placement
Component placement can affect signal quality, emissions, and temperature of a board design. This
section will provide guidelines for component placement.
Careful component placement can:
Decrease potential problems directly related to electromagnetic interference (EMI), which could
cause failure to meet FCC and IEEE test specifications.
Simplify the task of routing traces. To some extent, component orientation will affect the
complexity of trace routing. The overall objective is to minimize turns and crossovers between
traces.
Minimizing the amount of space needed for the Ethernet LAN interface is important because all other
interfaces will compete for physical space on a motherboard near the connector edge. As with most
subsystems, the Ethernet LAN circuits need to be as close as possible to the connector. Thus, it is
imperative that all designs be optimized to fit in a very small space.
9.9.3.2.
Crystals and Oscillators
To minimize the effects of EMI, clock sources should not be placed near I/O ports or board edges.
Radiation from these devices may be coupled onto the I/O ports or out of the system chassis. Crystals
should also be kept away from the ethernet magnetics module to prevent interference of communication.
The retaining straps of the crystal (if they should exist) should be grounded to prevent the possibility
radiation from the crystal case and the crystal should lay flat against the PC board to provide better
coupling of the electromagnetic fields to the board.
For a noise free and stable operation, place the crystal and associated discrete components as close as
possible to the Intel 82562ET/EM, keeping the trace length as short as possible and do not route any
noisy signals in this area.
9.9.3.3.
Intel 82562ET / Intel 82562EM Termination Resistors
The 100 ± 1% resistor used to terminate the differential transmit pairs (TDP/TDN) and the 121
± 1% receive differential pairs (RDP/RDN) should be placed as close to the Platform LAN connect
component (Intel 82562ET or Intel 82562EM) as possible. This is due to the fact these resistors are
terminating the entire impedance that is seen at the termination source (i.e. Intel 82562ET), including the
wire impedance reflected through the transformer.
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Figure 120. Intel 82562ET / Intel 82562EM Termination
Intel
ICH4-M
Intel®
LAN Connect Interface
82562ET/EM
Magnetics
Module
RJ45
Place termination resistors as close to the Intel®
82562ET/EM as possible
9.9.3.4.
Critical Dimensions
There are two dimensions to consider during layout. Distance ‘A’ from the line RJ-45 connector to the
magnetics module and distance ‘B’ from the Intel 82562ET or Intel 82562EM to the magnetics module.
The combined total distances A and B must not exceed 4 inches (preferably, less than 2 inches). See
Figure 121.
Figure 121. Critical Dimensions for Component Placement
B
Intel
ICH4-M
Intel
82562ET/EM
A
Magnetics
Module
Line
RJ45
EEPROM
Distance
Priority
Guideline
A
1
< 1 inch
B
2
< 1 inch
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9.9.3.4.1.
Distance from Magnetics Module to RJ-45 (Distance A)
The distance A in Figure 121 above should be given the highest priority in board layout. The distance
between the magnetics module and the RJ-45 connector should be kept to less than one inch of
separation. The following trace characteristics are important and should be observed:
Differential Impedance: The differential impedance should be 100 . The single ended trace
impedance will be approximately 50 ; however, the differential impedance can also be affected by
the spacing between the traces.
Trace Symmetry: Differential pairs (such as TDP and TDN) should be routed with consistent
separation and with exactly the same lengths and physical dimensions (for example, width).
Caution: Asymmetric and unequal length traces in the differential pairs contribute to common mode noise. This
can degrade the receive circuit’s performance and contribute to radiated emissions from the transmit
circuit. If the Intel 82562ET must be placed further than a couple of inches from the RJ-45 connector,
distance B can be sacrificed. Keeping the total distance between the Intel 82562ET and RJ-45 will as
short as possible should be a priority.
Note: Measured trace impedance for layout designs targeting 100 often result in lower actual impedance.
OEMs should verify actual trace impedance and adjust their layout accordingly. If the actual impedance
is consistently low, a target of 105 to 110 should compensate for second order effects.
9.9.3.4.2.
Distance from Intel 82562ET / 82562ET to Magnetics Module (Distance B)
Distance B should also be designed to be less than one inch between devices. The high-speed nature of
the signals propagating through these traces requires that the distance between these components be
closely observed. In general, any section of traces that is intended for use with high-speed signals should
observe proper termination practices. Proper termination of signals can reduce reflections caused by
impedance mismatches between device and traces. The reflections of a signal may have a high
frequency component that may contribute more EMI than the original signal itself. For this reason, these
traces should be designed to a 100- differential value. These traces should also be symmetric and equal
length within each differential pair.
9.9.3.5.
Reducing Circuit Inductance
The following guidelines show how to reduce circuit inductance in both back planes and motherboards.
Traces should be routed over a continuous ground plane with no interruptions. If there are vacant areas
on a ground or power plane, the signal conductors should not cross the vacant area. This increases
inductance and associated radiated noise levels. Noisy logic grounds should be separated from analog
signal grounds to reduce coupling. Noisy logic grounds can sometimes affect sensitive DC subsystems
such as analog to digital conversion, operational amplifiers, etc. All ground vias should be connected to
every ground plane; and similarly, every power via, to all power planes at equal potential. This helps
reduce circuit inductance. Another recommendation is to physically locate grounds to minimize the loop
area between a signal path and its return path. Rise and fall times should be as slow as possible because
signals with fast rise and fall times contain many high frequency harmonics that can radiate
significantly. The most sensitive signal returns closest to the chassis ground should be connected
together. This will result in a smaller loop area and reduce the likelihood of crosstalk. The effect of
different configurations on the amount of crosstalk can be studied using electronics modeling software.
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9.9.3.5.1.
Terminating Unused Connections
In Ethernet designs, it is common practice to terminate unused connections on the RJ-45 connector and
the magnetics module to ground. Depending on overall shielding and grounding design, this may be
done to the chassis ground, signal ground, or a termination plane. Care must be taken when using
various grounding methods to insure that emission requirements are met. The method most often
implemented is called the “Bob Smith” Termination. In this method, a floating termination plane is cut
out of a power plane layer. This floating plane acts as a plate of a capacitor with an adjacent ground
plane. The signals can be routed through 75- resistors to the plane. Stray energy on unused pins is then
carried to the plane.
9.9.3.5.2.
Termination Plane Capacitance
Intel recommends that the termination plane capacitance equal a minimum value of 1500 pF. This helps
reduce the amount of crosstalk on the differential pairs (TDP/TDN and RDP/RDN) from the unused
pairs of the RJ-45. Pads may be placed for an additional capacitance to chassis ground, which may be
required if the termination plane capacitance is not large enough to pass EFT (Electrical Fast Transient)
testing. If a discrete capacitor is used, to meet the EFT requirements it should be rated for at least 1000
Vac.
Figure 122. Termination Plane
TDP
N/C
TDN
RDP
RJ-45
RDN
Magnetics Module
Termination Plane
Addition Capacitance that may need to be
added for EFT testing
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9.9.4.
Intel 82562ET/EM Disable Guidelines
To disable the Intel 82562ET/EM, the device must be isolated (disabled) prior to reset (RSM_PWROK)
asserting. Using a GPIO, such as GPO28 to be LAN_Enable (enabled high), LAN will default to
enabled on initial power-up and after an AC power loss. This circuit shown below will allow this
behavior. The BIOS controlling the GPIO can disable the LAN micro-controller.
Note: LAN_RST# needs to be held low for 10 ms after power is stable. It is assumed that RSMRST# logic
will provide this delay. Because GPIO28 will default to high during power up, an AND gate has been
implemented to ensure the required delay for LAN_RST# is met.
Figure 123. Example Intel 82562ET/EM Disable and Power Down Circuitry
RSMRST# Logic
(10 ms delay)
VccSus3_3
RSMRST#
470 Ω ± 5%
To ICH5
LAN_RST#
LAN Device Disable
Test_En
10 KΩ ± 5%
From ICH5
Isol_Tck
GPIO[28]
(LAN_Enable)
Isol_Ti
10 KΩ ± 5%
MMBT2222
Isol_Tex
Rpack
100 Ω ± 5%
There are four pins which are used to put the Intel 82562ET/EM controller in different operating states:
Test_En, Isol_Tck, Isol_Ti, and Isol_Tex. The table below describes the operational/disable features for
this design.
The four control signals shown in the below table should be configured as follows: Test_En should be
pulled-down through a 100- resistor. The remaining three control signals should each be connected
through 100- series resistors to the common node “Intel 82562ET/EM _Disable” of the disable circuit.
Table 60. Intel 82562ET/EM Control Signals
Test_En
Isol_Tck
Isol_Ti
Isol_Tex
State
0
0
0
0
Enabled
0
1
1
1
Disabled w/ Clock (low power)
1
1
1
1
Disabled w/out Clock (lowest power)
In addition, if the LAN Connect Interface of the Intel 82801DBM ICH4-M is not used, the VccLAN1_5
and the VccLAN3_3 are still required to be powered during normal operating states. It is acceptable to
power the VccLAN1_5 and VccLAN3_3 power pins by the same voltage source that supplies power to
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the Vcc1_5 and Vcc3_3 power pins. Also, the LAN_RST# pin of the ICH4-M should be pulled-down to
GND with a 10-k resistor to keep the interface disabled.
9.9.5.
Design and Layout Consideration for Intel 82540EP / 82551QM
For specific design and layout considerations for the Intel 82540EP Gigabit Ethernet Controller and the
Intel 82551QM Faster Ethernet Controller, please refer to the following documents:
82551QM / 82540EM Interchangeable LOM Design Application Note (AP 432) (Reference
#10565)
82540EP Gigabit Ethernet Controller Networking Silicon Product Preview Datasheet
82540EP Gigabit Ethernet Controller Specification Update
82540EP/82541EI & 82562EZ(EX) Dual Footprint Design Guide Application Note (AP-444)
(Reference# 12504)
9.9.6.
General Intel 82562ET / 82562EM / 82551QM / 82540EP
Differential Pair Trace Routing Considerations
Trace routing considerations are important to minimize the effects of crosstalk and propagation delays
on sections of the board where high-speed signals exist. Signal traces should be kept as short as possible
to decrease interference from other signals, including those propagated through power and ground
planes.
Observe the following suggestions to help optimize board performance.
Note: Some suggestions are specific to a 4.3-mil stack-up.
Maintain constant symmetry and spacing between the traces within a differential pair.
Keep the signal trace lengths of a differential pair equal to each other.
Keep the total length of each differential pair under 4 inches. (Many customer designs with
differential traces longer than 5 inches have had one or more of the following issues: IEEE phy
conformance failures, excessive EMI (Electro Magnetic Interference), and/or degraded receive
BER (Bit Error Rate).)
Do not route the transmit differential traces closer than 100 mils to the receive differential traces.
Do not route any other signal traces both parallel to the differential traces, and closer than 100 mils
to the differential traces (300 mils is recommended).
Keep maximum separation between differential pairs to 7 mils.
For high-speed signals, the number of corners and vias should be kept to a minimum. If a 90° bend
is required, Intel recommends using two 45° bends instead. Refer to Figure 124.
Traces should be routed away from board edges by a distance greater than the trace height above
the ground plane. This allows the field around the trace to couple more easily to the ground plane
rather than to adjacent wires or boards.
Do not route traces and vias under crystals or oscillators. This will prevent coupling to or from the
clock. And as a general rule, place traces from clocks and drives at a minimum distance from
apertures by a distance that is greater than the largest aperture dimension.
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Figure 124. Trace Routing
45
Trace Routing
9.9.6.1.1.
Trace Geometry and Length
The key factors in controlling trace EMI radiation are the trace length and the ratio of trace-width to
trace-height above the ground plane. To minimize trace inductance, high-speed signals and signal layers
that are close to a ground or power plane should be as short and wide as practical. Ideally, this trace
width to height above the ground plane ratio is between 1:1 and 3:1. To maintain trace impedance, the
width of the trace should be modified when changing from one board layer to another if the two layers
are not equidistant from the power or ground plane. Differential trace impedances should be controlled
to be ~100 . It is necessary to compensate for trace-to-trace edge coupling, which can lower the
differential impedance by up to 10 , when the traces within a pair are closer than 30 mils (edge to
edge).
Traces between decoupling and I/O filter capacitors should be as short and wide as practical. Long and
thin traces are more inductive and would reduce the intended effect of decoupling capacitors. Also for
similar reasons, traces to I/O signals and signal terminations should be as short as possible. Vias to the
decoupling capacitors should be sufficiently large in diameter to decrease series inductance.
Additionally, the PLC should not be closer than one inch to the connector/magnetics/edge of the board.
9.9.6.1.2.
Signal Isolation
Some rules to follow for signal isolation:
Separate and group signals by function on separate layers if possible. Maintain a gap of 100 mils
between all differential pairs (Ethernet) and other nets, but group associated differential pairs
together. NOTE: Over the length of the trace run, each differential pair should be at least 0.3
inches away from any parallel signal traces.
Physically group together all components associated with one clock trace to reduce trace length and
radiation.
Isolate I/O signals from high speed signals to minimize crosstalk, which can increase EMI emission
and susceptibility to EMI from other signals.
Avoid routing high-speed LAN traces near other high-frequency signals associated with a video
controller, cache controller, CPU, or other similar devices.
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9.9.6.1.3.
Magnetics Module General Power and Ground Plane Considerations
To properly implement the common mode choke functionality of the magnetics module the chassis or
output ground (secondary side of transformer) should be separated from the digital or input ground
(primary side) by a physical separation of 100 mils minimum
Figure 125. Ground Plane Separation
0.10 Inches Minimum Spacing
Magnetics Module
Void or Separate
Ground Plane
Separate Chassis Ground Plane
Good grounding requires minimizing inductance levels in the interconnections and keeping ground
returns short, signal loop areas small, and power inputs bypassed to signal return, will significantly
reduce EMI radiation.
Some rules to follow that will help reduce circuit inductance in both back planes and motherboards.
Route traces over a continuous plane with no interruptions (don’t route over a split plane). If there
are vacant areas on a ground or power plane, avoid routing signals over the vacant area. This will
increase inductance and EMI radiation levels.
Separate noisy digital grounds from analog grounds to reduce coupling. Noisy digital grounds may
affect sensitive DC subsystems.
All ground vias should be connected to every ground plane; and every power via should be
connected to all power planes at equal potential. This helps reduce circuit inductance.
Physically locate grounds between a signal path and its return. This will minimize the loop area.
Avoid fast rise/fall times as much as possible. Signals with fast rise and fall times contain many
high frequency harmonics, which can radiate EMI.
The ground plane beneath the filter/transformer module should be split. The RJ-45 connector side
of the transformer module should have chassis ground beneath it. By splitting ground planes
beneath transformer, noise coupling between the primary and secondary sides of the transformer
and between the adjacent coils in the transformer is minimized. There should not be a power plane
under the magnetics module.
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9.9.6.2.
Common Physical Layout Issues
Here is a list of common physical layer design and layout mistakes in LAN on motherboard designs.
1. Unequal length of the two traces within a differential pair. Inequalities create common-mode noise
and will distort the transmit or receive waveforms.
2. Lack of symmetry between the two traces within a differential pair. (Each component and/or via
that one trace encounters, the other trace must encounter the same component or a via at the same
distance from the PLC.) Asymmetry can create common-mode noise and distort the waveforms.
3. Excessive distance between the PLC and the magnetics or between the magnetics and the RJ-45
connector. Beyond a total distance of about 4 inches, it can become extremely difficult to design
a spec-compliant LAN product. Long traces on FR4 (fiberglass epoxy substrate) will attenuate the
analog signals. In addition, any impedance mismatch in the traces will be aggravated if they are
longer (see #9 below). The magnetics should be as close to the connector as possible (≤ one inch).
4. Routing any other trace parallel to and close to one of the differential traces. Crosstalk getting
onto the receive channel will cause degraded long cable BER. Crosstalk getting onto the transmit
channel can cause excessive emissions (failing FCC) and can cause poor transmit BER on long
cables. At a minimum, other signals should be kept 0.3 inches from the differential traces.
5. Routing the transmit differential traces next to the receive differential traces. The transmit trace
that is closest to one of the receive traces will put more crosstalk onto the closest receive trace and
can greatly degrade the receiver's BER over long cables. After exiting the PLC, the transmit traces
should be kept 0.3 inches or more away from the nearest receive trace. The only possible
exceptions are in the vicinities where the traces enter or exit the magnetics, the RJ-45, and the
PLC.
6. Use of an inferior magnetics module. The magnetics modules that we use have been fully tested
for IEEE PLC conformance, long cable BER, and for emissions and immunity. (Inferior
magnetics modules often have less common-mode rejection and/or no auto transformer in the
transmit channel.)
7. Use of an 82555 or 82558 physical layer schematic in a PLC design. The transmit terminations
and decoupling are different. There are also differences in the receive circuit. Please follow the
appropriate reference schematic or Application Note.
8. Not using (or incorrectly using) the termination circuits for the unused pins at the RJ-45 and for
the wire-side center-taps of the magnetics modules. These unused RJ pins and wire-side centertaps must be correctly referenced to chassis ground via the proper value resistor and a capacitance
or termplane. If these are not terminated properly, there can be emissions (FCC) problems, IEEE
conformance issues, and long cable noise (BER) problems. The Application Notes have
schematics that illustrate the proper termination for these unused RJ pins and the magnetics
center-taps.
9.
Incorrect differential trace impedances. It is important to have ~100- impedance between the
two traces within a differential pair. This becomes even more important as the differential traces
become longer. It is very common to see customer designs that have differential trace impedances
between 75 and 85 , even when the designers think they've designed for 100 . (To calculate
differential impedance, many impedance calculators only multiply the single-ended impedance by
two. This does not take into account edge-to-edge capacitive coupling between the two traces.
When the two traces within a differential pair are kept close† to each other, the edge coupling can
lower the effective differential impedance by 5 - 20 . A 10- - 15- drop in impedance is
common.) Short traces will have fewer problems if the differential impedance is a little off.
10. Use of capacitor that is too large between the transmit traces and/or too much capacitance from
the magnetic's transmit center-tap (on the Intel 82562ET side of the magnetics) to ground. Using
capacitors more than a few pF in either of these locations can slow the 100 Mbps rise and fall time
so much that they fail the IEEE rise time and fall time specs. This will also cause return loss to fail
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at higher frequencies and will degrade the transmit BER performance. Caution should be
exercised if a cap is put in either of these locations. If a cap is used, it should almost certainly be
less than 22 pF. (6 pF to 12 pF values have been used on past designs with reasonably good
success.) These caps are not necessary, unless there is some overshoot in 100 Mbps mode.
Note: It is important to keep the two traces within a differential pair close† to each other. Keeping them close†
helps to make them more immune to crosstalk and other sources of common-mode noise. This also
means lower emissions (i.e. FCC compliance) from the transmit traces, and better receive BER for the
receive traces.
†
Close should be considered to be less than 0.030 inches between the two traces within a differential
pair. 0.007 inch trace-to-trace spacing is recommended.
9.10.
Power Management Interface
9.10.1.
SYS_RESET# Usage Model
The System Reset signal (SYS_RESET#) of the Intel 82801DBM ICH4-M can be connected directly to
a reset button or any other equivalent driver in the system where the desired effect is to immediately put
the system into reset. If an Intel® Pentium® M Processor / Intel® Celeron® M Processor ITP700FLEX
debug port is implemented on the system, Intel recommends that the DBR# signal of the ITP interface
be connected to SYS_RESET# as well. If SYS_RESET# is implemented, a weak pull-up resistor pulledup to the 3.3-V standby rail (VccSUS3_3) should also be implemented to ensure that no potential
floating inputs to SYS_RESET# cause a system reset. The ICH4-M will debounce signals on this pin
(16 ms) and allow the SMBus to go idle before resetting the system. This delay to allow all outstanding
SMBus cycles to complete first and to prevent a slave device on the SMBus from “hanging” by resetting
in the middle of an SMBus cycle.
9.10.2.
PWRBTN# Usage Model
The Power Button signal (PWRBTN#) of the Intel 82801DBM ICH4-M can be connected directly to a
power button or any other equivalent driver (e.g. power management controller) where the desired effect
is to indicate a system request to go to a sleep state (if in a normal operating mode) or to cause a wake
event (if in a sleep state already). This signal is internally pulled-up in the ICH4-M to the 3.3-V standby
rail (VccSUS3_3) through a weak pull-up resistor (20 k nominal). The ICH4-M has 16 ms of internal
debounce logic on this pin.
9.10.3.
Power Well Isolation Control Strap Requirements
The RSMRST# signal of the ICH4-M must transition from 20% signal level to 80% signal level and
vice-versa in 50us. Slower transitions may result in excessive droop on the VCCRTC node during Sx-toG3 power state transitions (removal of AC power). Droop on this node can potentially cause the CMOS
to be cleared or corrupted, the RTC to loose time after several AC power cycles, or the intruder bit
might assert erroneously.
The circuit shown in the figure below can be implemented to control well isolation between the
VccSUS3_3 and RTC power-wells in the event that RSMRST# is not being actively asserted during the
discharge of the standby rail or does not meet the above rise/fall time
Intel® 855PM Chipset Platform Design Guide
225
I/O Subsystem
R
Figure 126. RTC Power Well Isolation Control
No Stuff
MMBT3906
RSMRST#
generation
from MB logic
RSMRST#
ICH4-M
10KΩ
BAV99
BAV99
2.2KΩ
No Stuff
9.11.
CPU I/O Signals Considerations
The Intel 82801DBM ICH4-M has been designed to be voltage compatible with the CMOS signals of
the processor. For Intel Pentium M/Intel Celeron M processor-based systems, the ICH4-M’s V_CPU_IO
rail uses the same 1.05-V voltage as the VCCP rails for the processor and Intel 855PM chipset. It is
important to verify that the voltage requirements of all processor and ICH4-M signals are compatible
with the FWH as well. See Section 9.7 for FWH details. Figure 127 shows a typical interface between
the ICH4-M, CPU, and FWH. See Section 4.1.4 for recommended topologies and routing guidelines.
226
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I/O Subsystem
R
Figure 127. Intel 82801DBM ICH4-M CPU CMOS Signals with CPU and FWH
V_CPU_IO
@ 1.05V
Intel
ICH4-M
FERR#
Output Signals
INIT#
Intel
Pentium M
processor
9
FWH
Intel® 855PM Chipset Platform Design Guide
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Intel® 855PM Chipset Platform Design Guide
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10.
Platform Clock Routing Guidelines
10.1.
Clock Routing Guidelines
Only one clock generator component is required in an Intel 855PM chipset based system. Clock
synthesizers that meet the Intel® CK-408 Clock Synthesizer/Driver Specification are suitable for an Intel
855PM chipset based system. For more information on CK-408 compliance, refer to the CK-408 Clock
Synthesizer/Driver Specification. The following tables and figure list and detail the Intel 855PM MCH
clock groups, the platform system clock cross-reference, and the platform clock distribution.
Table 61. Intel 855PM Chipset Clock Groups
Clock Name
Frequency
Receiver
HOST_CLK
100 MHz
CPU, Debug Port, and MCH
CLK66
66 MHz
Intel MCH and ICH4-M
AGPCLK
66 MHz
AGP Connector or AGP Device
CLK33
33 MHz
Intel ICH4-M, SIO, and FWH
CLK14
14.318 MHz
Intel ICH4-M and SIO
PCICLK
33 MHz
PCI Connector
USBCLK
48 MHz
Intel ICH4-M
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Table 62. Platform System Clock Cross-reference
Clock Group
HOST_CLK
Component
Component Pin Name
CPU
CPU
BCLK[0]
CPU#
CPU
BCLK[1]
CPU
Debug Port
BCLK[0]
CPU#
Debug Port
BCLK[1]
CPU
MCH
BCLK[0]
CPU#
MCH
BCLK[1]
MCH
66IN
ICH4-M
CLK66
CLK66
3V66
AGPCLK
3V66
AGP Connector or AGP Device
CLK
PCIF
ICH4-M
PCICLK
SIO
PCI_CLK
FWH
CLK
ICH4-M
CLK14
SIO
CLOCKI
PCI Connector or PCI Device #1
CLK
PCI Connector or PCI Device #2
CLK
PCI Connector or PCI Device #3
CLK
ICH4-M
CLK48
CLK33
CLK14
PCICLK
USBCLK
230
CK-408 Pin
PCI
REF0
PCI
USB
Intel® 855PM Chipset Platform Design Guide
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Figure 128. Platform Clock Topology Diagram
100 MHz
100 MHz
CPU#
CPU
CPU#
100 MHz
100 MHz
CPU
CPU
BCLK1#
BCLK1
Debug Port
BCLK2#
BCLK2
MCH
100 MHz
100 MHz
CPU#
CPU
66 MHz
66Buff
66 MHz
66Buff
AGP
Connector
33 MHz
PCIF
48 MHz
USB
14.318 MHz
CLK
ICH4-M
CLK66
PCICLK
CLK48
CLK14
PCI
Connectors
CLK
33 MHz
PCI
CLK
33 MHz
PCI
CLK
CK-408
66IN
66 MHz
66Buff
33 MHz
PCI
REFO
BCLK0#
BCLK0
14.318 MHz
PCI
33 MHz
SIO
CLOCKI
PCI_CLK
FWH
33 MHz
PCI
Intel® 855PM Chipset Platform Design Guide
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10.2.
Clock Group Topology and Layout Routing Guidelines
10.2.1.
HOST_CLK Clock Group
The clock synthesizer provides three pairs of 100-MHz differential clock outputs utilizing a 0.7-V
voltage swing. The 100-MHz differential clocks are driven to the Intel Pentium M/Intel Celeron M
processor, the Intel 855PM MCH, and the processor debug port with the topology shown in the figure
below.
The clock driver differential bus output structure is a “Current Mode Current Steering” output which
develops a clock signal by alternately steering a programmable constant current to the external
termination resistors Rt. The resulting amplitude is determined by multiplying IOUT by the value of Rt.
The current IOUT is programmable by a resistor and an internal multiplication factor so the amplitude of
the clock signal can be adjusted for different values of Rt to match impedances or to accommodate
future load requirements.
The recommended termination for the differential bus clock is a “Source Shunt termination.” Refer to
Figure 129 for an illustration of this terminology scheme. Parallel Rt resistors perform a dual function,
converting the current output of the clock driver to a voltage and matching the driver output impedance
to the transmission line. The series resistors Rs provide isolation from the clock driver’s output
parasitics, which would otherwise appear in parallel with the termination resistor Rt.
The value of Rt should be selected to match the characteristic impedance of the system board and Rs
should be 33 ± 5%. Simulations have shown that Rs values above 33 provide no benefit to signal
integrity but only degrade the edge rate.
The MULT0 pin (CK-408 pin #43) should be pulled-up through a 10 k
multiplication factor to 6.
to VCC – setting the
The IREF pin (CK-408 pin # 42) should be tied to ground through a 475
IREF 2.32 mA.
± 1 % resistor – making the
Figure 129. Source Shunt Termination Topology
Rs
L1
L2
L4
L1'
L2'
L4'
Clock
Driver
CPU or
MCH
Rt
232
L3'
L3
Rs
Rt
Intel® 855PM Chipset Platform Design Guide
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Table 63. BCLK/BCLK#[1:0] Routing Guidelines
Parameter
Routing Guidelines
Figure
Notes
Signal Group
HOST_CLK
1
Motherboard Topology
Source Shunt Termination
Reference Plane
Ground Referenced (Contiguous over entire
length)
BCLK Skew Between Agents
500 ps Total Budget: 250 ps for Flight Skew;
100 ps for Pin-to-Pin Skew; 150 ps for Jitter
Differential Pair Spacing
7 mils
6, 7
Trace Width
4 mils
8
Spacing to Other Traces
Min = 25 mils
System Board Impedance – Differential
100
System Board Impedance – Odd Mode
50
± 15%
9
± 15%
10
Processor Routing Length – L1, L1’: Clock Driver
Max = 0.50 inches
to Rs
Processor Routing Length – L2, L2’: Rs to Rt
Node
Min = 0 inches
Processor Routing Length – L3, L3’: Rt Node to
Rt
Min = 0 inches
Processor Routing Length – L4, L4’: Rt Node to
Receiver
Min = 2.0 inches
Max = 0.20 inches
Max = 0.50 inches
MCH Routing Length – L3, L3’: Rt Node to Rt
MCH Routing Length – L4, L4’: Rt Node to
Receiver
Figure 129
14
Figure 129
14
Figure 129
14
Figure 129
Max = 8.0 inches
MCH Routing Length – L1, L1’: Clock Driver to Rs Max = 0.50 inches
MCH Routing Length – L2, L2’: Rs to Rt Node
Figure 130 2, 3, 4, 5
Min = 0 inches
Max = 0.20 inches
Min = 0 inches
Max = 0.50 inches
Min = 2.0 inches
Figure 129
14
Figure 129
14
Figure 129
14
Figure 129
Max = 8.0 inches
Processor L1/L1’ and MCH L1/L1’ Length
Matching
± 10 mils
16
Clock Driver-to-Processor and Clock Driver-toMCH Length Matching (L1 + L2 + L4)
- 400 mils ± 50 mils
11
Processor BCLK (L1 + L2 + L4) and BCLK# (L1’
+ L2’ + L4’) Length Matching
± 10 mils
MCH BCLK (L1 + L2 + L4) and BCLK# (L1’ + L2’
+ L4’) Length Matching
± 10 mils
Series Termination Resistor (Rs)
33
Parallel Termination Resistor (Rt)
49.9
± 5%
± 1% (for 55
MB impedance)
Figure 129
12
Figure 129
13
NOTES:
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233
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1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
10.2.1.1.
Recommended resistor values and trace lengths may change in a later revision of the design guide.
This number does not include clock driver common mode.
The skew budget includes clock driver output pair to output pair jitter (differential jitter), and skew, clock skew
due to interconnect process variation, and static skew due to layout differences between clocks to all bus agents.
The interconnect portion of the total budget for this specification assumes clock pairs are routed on multiple
routing layers and routed no longer than the maximum recommended lengths.
Skew measured at the load between any two, bus agents. Measured at the crossing point.
Edge-to-edge spacing between the two traces of any differential pair. Uniform spacing should be maintained
along the entire length of the trace.
Clock traces are routed in a differential configuration. Maintain the minimum recommended spacing between the
two traces of the pair. Do not exceed the maximum trace spacing, as this will degrade the noise rejection of the
network.
Set the line width to meet correct system board impedance. The line width value provided here is a
recommendation to meet the proper trace impedance based on the recommended stack-up.
The differential impedance of each clock pair is approximately 2*Z single-ended*(1-2*Kb) where Kb is the
backwards crosstalk coefficient. For the recommended trace spacing, Kb is very small and the effective
differential impedance is approximately equal to 2 times the single-ended impedance of each half of the pair.
The single ended impedance of both halves of a differential pair should be targeted to be of equal value. They
should have the same physical construction. If the BCLK traces vary within the tolerances specified, both traces
of a differential pair must vary equally.
Values are based on socket dimensions/tolerances/parasitics outlined in the Intel® Mobile Processor MicroFCPGA Socket (mPGA479M) Design Guidelines (Order number: 298520). Or in general terms, a 4mm ± 5%
socket with lumped parasitics model. Length compensation for the processor socket and package delay is added
to chipset routing to match electrical lengths between the chipset and the processor from the die pad of each.
Therefore, the system board trace length for the chipset will be longer than that for the processor. e.g. If Clock
Driver-to-MCH = 4.0” then Clock Driver-to-Processor = 3.6” ± 50 mils.
Rs value of 33Ω has shown to be an effective solution.
Rt shunt termination value should match the system board impedance.
Minimize L1, L2 and L3 lengths. Long lengths on L2 and L3 degrade effectiveness of source termination and
contribute to ring back.
The goal of constraining all bus clocks to one physical routing layer is to minimize the impact on skew due to
variations in Er and the impedance variations due to physical tolerances of circuit board material.
Minimize the trace length difference between L1/L1’ of the processor and MCH BCLK/BCLK# pair to minimize
skew. Length matching of L1/L1’ within 10 mils should be between the shortest BCLK/BCLK# signal of one pair
to the longest BCLK/BCLK# signal of the other pair.
BCLK Length Matching Requirements
To compensate for the extra delay introduced by the processor socket dimensions/tolerances/parasitics
as well as the package parasitics, the Clock Driver-to-MCH (L1 + L2 + L4) motherboard routing will be
longer than Clock Driver-to-Processor (L1 + L2 + L4) motherboard routing. Clock Driver-to-MCH
routing should be 400 mils ± 50 mils longer than Clock Driver-to-Processor routing. i.e. the
following relationship should be adhered to:
Clock Driver-to-Processor (L1 + L2 + L4) = Clock Driver-to-MCH (L1 + L2 + L4) – 400 mils ± 50 mils
In order to minimize the clock skew between the processor and the MCH, the L1/L1’ segments of the
two FSB agents should be exactly trace length matched if possible. The routing should be done such that
the shortest L1/L1’ segment of the processor is matched within ± 10 mils of the longest L1/L1’ segment
of the MCH. i.e. the following relationship should be adhered to:
Processor shortest(L1/L1’) = MCH longest(L1/L1’) ± 10 mils.
Additionally, the routing of each half of the host clock pair for the processor and MCH should be trace
length matched within ± 10 mils of its complement’s routing. i.e. the following relationships should be
adhered to:
Processor (L1 + L2 + L4) = Processor (L1’ + L2’ + L4’) ± 10 mils
and
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Intel® 855PM Chipset Platform Design Guide
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MCH (L1 + L2 + L4) = MCH (L1’ + L2’ + L4’) ± 10 mils
10.2.1.2.
BCLK General Routing Guidelines
Below is the general guidelines for routing the BCLK:
1. When routing the 100-MHz differential clocks, do not split up the two halves of a differential
clock pair between layers and route to all agents on the same physical routing layer referenced to
ground.
2. If a layer transition is required, make sure that the skew induced by the vias used to transition
between routing layers is compensated in the traces to other agents.
3. Do not place vias between adjacent complementary clock traces and avoid differential vias. Vias
placed in one half of a differential pair must be matched by a via in the other half. Differential vias
can be placed within length L1, between clock driver and Rs, if needed to shorten length L1.
10.2.1.3.
EMI constraints
Clocks are a significant contributor to EMI and should be treated with care. The following
recommendations can aid in EMI reduction:
1. Maintain uniform spacing between the two halves of differential clocks.
2. Route clocks on physical layer adjacent to the VSS reference plane only.
Figure 130. Clock Skew as Measured from Agent-to-Agent
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10.2.2.
CLK66 Clock Group
The driver is the clock synthesizer 66-MHz clock output buffer and the receiver is the 66-MHz clock
input buffer at the Intel 855PM MCH and the Intel 82801DBM ICH4-M. Note that the goal is to have as
little skew between the clocks within this group as possible.
Figure 131. CLK66 Group Topology
R1
A
B
Clock
Driver
MCH and
ICH4-M
Table 64. CLK66 Group Routing Guidelines
Parameter
Routing Guidelines
Signal Group
CLK66
Motherboard Topology
Point-to-Point
Reference Plane
Ground Referenced (Contiguous over entire
length)
Characteristic Trace Impedance (Zo)
55
Trace Width
4 mils
Trace to Space Ratio
1:5 (e.g. 4 mils trace 20 mils space)
Group Spacing
Isolation spacing from non-Clock signals =
20 mils minimum
Trace Length – A
Trace Length – B
Figure
Notes
1
± 15%
Min = 0 inches
Max = 0.50 inches
Min = 4.0 inches
Max = 8.50 inches
± 5%
Figure 131
Figure 131
Series Termination Resistor (R1)
33
Figure 131
Skew Requirements
Minimal skew (~ 0) between clocks within the
CLK66 group
Clock Driver MCH
X
2
Clock Driver to ICH4-M
X ± 100 mils
2
NOTES:
1. Recommended resistor values and trace lengths may change in a later revision of the design guide.
2. If the trace length from clock driver to MCH is X, then the trace length from clock driver to ICH4-M must be length
matched within 100 mils.
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10.2.3.
AGPCLK Clock Group
The driver is the clock synthesizer 66-MHz clock output buffer and the receiver is the 66-MHz clock
input buffer at the AGP device. Note that the goal is to have minimal (~ 0) skew between this clock and
the clocks in the clock group CLK66.
Figure 132. AGPCLK to AGP Connector Topology
R1
A
B
C
Trace on AGP
Card
Clock
Driver
AGP
Connector
AGP
Device
Figure 133. AGPCLK to AGP Device Down Topology
R1
A
Clock
Driver
Intel® 855PM Chipset Platform Design Guide
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237
Platform Clock Routing Guidelines
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Table 65. AGPCLK Routing Guidelines
Parameter
Routing Guidelines
Figure
Notes
Signal Group
AGPCLK
1
Motherboard Topology
Point-to-Point
Reference Plane
Ground Referenced (Contiguous over entire
length)
Characteristic Trace Impedance (Zo)
55
Trace Width
4 mils
Trace to Space Ratio
1:5 (e.g. 4 mils trace 20 mils space)
Group Spacing
Isolation spacing from non-Clock signals =
20 mils minimum
Trace Length – A
Trace length matched to CLK66 Trace A
Figure 132,
Figure 133
2
Trace Length – B (Option #1)
Must be exactly trace length matched to
CLK66 Trace B
Figure 133
3
Trace Length – B (Option #2)
Must be exactly trace length matched to
[(CLK66 Trace B) - 4.0 inches]
Figure 132
4
Trace Length – C
Routed 4.0 inches per the AGP Specification Figure 132
Series Termination Resistor (R1)
33
Skew Requirements
Minimal skew (~ 0) between AGPCLK and
CLK66 group
± 15%
± 5%
Figure 133
NOTES:
1. Recommended resistor values and trace lengths may change in a later revision of the design guide.
2. AGPCLK Trace A should be trace length matched to CLK66 Trace A as closely as possible.
3. To achieve minimal skew for AGP device down topologies, AGPCLK Trace B should be matched as closely to
CLK66 Trace B as possible.
4. To achieve minimal skew for AGP connector topologies, AGPCLK Trace B should be matched as closely to
CLK66 Trace B as possible. Note that Trace C is assumed to be 4.0 inches on the AGP card and should be
subtracted from the AGPCLK Trace B length when matching to CLK66 Trace B.
10.2.4.
CLK33 Clock Group
The driver is the clock synthesizer 33-MHz clock output buffer and the receiver is the 33-MHz clock
input buffer at the ICH4-M, FWH, and SIO.
Note: The goal is to have minimal (~ 0) skew between the clocks within this group, and also minimal (~ 0)
skew between the clocks of this group and that of group CLK66.
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Figure 134. CLK33 Group Topology
R1
A
B
ICH4-M,
SIO,
FWH
Clock
Driver
Table 66. CLK33 Group Routing Guidelines
Parameter
Routing Guidelines
Figure
Signal Group
CLK33
Motherboard Topology
Point-to-Point
Reference Plane
Ground Referenced (Contiguous over entire
length)
Characteristic Trace Impedance (Zo)
55
Trace Width
4 mils
Trace to Space Ratio
1:5 (e.g. 4 mils trace 20 mils space)
Group Spacing
Isolation spacing from non-Clock signals =
20 mils minimum
Trace Length – A
Must be exactly trace length matched to
CLK66 Trace A
Figure 134
Trace Length – B
Must be exactly trace length matched to
CLK66 Trace B
Figure 134
Series Termination Resistor (R1)
33
Figure 134
Skew Requirements
Minimal skew (~ 0) between CLK33 group
and CLK66 group
Notes
1
± 15%
± 5%
NOTES:
1. Recommended resistor values and trace lengths may change in a later revision of the design guide.
10.2.5.
PCICLK Clock Group
The driver is the clock synthesizer 33-MHz clock output buffer and the receiver is the 33-MHz clock
input buffer at the PCI devices on the PCI cards. Note that the goal is to have a maximum of ±1 ns skew
between the clocks within this group, and also a maximum of ± 1 ns skew between the clocks of this
group and that of group CLK33.
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Figure 135. PCICLK Group to PCI Device Down Topology
R1
A
B
Clock
Driver
PCI Device
Table 67. PCICLK Group Routing Guidelines
Parameter
Routing Guidelines
Figure
Signal Group
PCICLK
Motherboard Topology
Point-to-Point
Reference Plane
Ground Referenced (Contiguous over entire
length)
Characteristic Trace Impedance (Zo)
55
Trace Width
5 mils
Trace to Space Ratio
1:4 (e.g. 5 mils trace 20 mils space)
Group Spacing
Isolation spacing from non-Clock signals =
20 mils minimum
Trace Length – A
Must be exactly trace length matched to
CLK33 Trace A
Figure 135
Trace Length – B
Must be exactly trace length matched to
CLK33 Trace B
Figure 135
Series Termination Resistor (R1)
33
Figure 135
Skew Requirements
Maximum of ± 1 ns of skew between clocks
within the PCICLK group and a maximum of
± 1 ns of skew between the clocks of this
group and those of CLK33
Notes
1
±15%
± 5%
NOTE: Recommended resistor values and trace lengths may change in a later revision of the design guide.
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Figure 136. PCICLK Group to PCI Slot Topology
R1
A
B
C
Trace on PCI
Card
Clock
Driver
PCI
Connector
PCI Device
Table 68. PCICLK Group Routing Guidelines
Parameter
Routing Guidelines
Figure
Signal Group
PCICLK
Motherboard Topology
Point-to-Point
Reference Plane
Ground Referenced (Contiguous over entire
length)
Characteristic Trace Impedance (Zo)
55
Trace Width
5 mils
Trace to Space Ratio
1:2 (e.g. 5 mils trace 10 mils space)
Group Spacing
Isolation spacing from non-Clock signals =
10 mils minimum
Trace Length – A
Must be exactly trace length matched to
CLK33 Trace A
Figure 136
Trace Length – B
(CLK33 Trace B) – 2.5”
Figure 136
Trace Length – C
Routed 2.5” per the PCI Specification
Figure 136
Series Termination Resistor (R1)
33
Figure 136
Skew Requirements
Maximum of ± 1 ns of skew between clocks
within the PCICLK group and a maximum of
± 1 ns of skew between the clocks of this
group and those of CLK33
Notes
1
± 15%
± 5%
NOTE: Recommended resistor values and trace lengths may change in a later revision of the design guide.
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10.2.6.
USBCLK Clock Group
The driver is the clock synthesizer USB clock output buffer and the receiver is the USB clock input
buffer at the ICH4-M. Note that this clock is asynchronous to any other clock on the board.
Figure 137. USBCLK Group Topology
R1
A
B
Clock
Driver
ICH4-M
Table 69. USBCLK Routing Guidelines
Parameter
Routing Guidelines
Signal Group
USBCLK
Motherboard Topology
Point-to-Point
Reference Plane
Ground Referenced (Contiguous over entire
length)
Characteristic Trace Impedance (Zo)
55
Trace Width
5 mils
Trace to Space Ratio
1:2 (e.g. 5 mils trace 10 mils space)
Group Spacing
Isolation spacing from non-Clock signals =
20 mils minimum
Trace Length – A
Trace Length – B
Figure
Notes
1
± 15%
Min = 0 inches
Max = 0.50 inches
Min = 3.0 inches
Max = 12.0 inches
Series Termination Resistor (R1)
33
± 5%
Skew Requirements
None – USBCLK is asynchronous to any
other clock on the platform
Figure 137
Figure 137
Figure 137
NOTE: Recommended resistor values and trace lengths may change in a later revision of the design guide.
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10.2.7.
CLK14 Clock Group
The driver is the clock synthesizer 14.318-MHz clock output buffer and the receiver is the 14.318-MHz
clock input buffer at the ICH4-M and SIO. Note that the clocks within this group should have minimal
skew (~ 0) between each other, however each of the clocks in this group is asynchronous to clocks of
any other group.
Figure 138. CLK14 Group Topology
R1
A
B
Clock
Driver
ICH4-M, SIO
Table 70. CLK14 Group Routing Guidelines
Parameter
Routing Guidelines
Signal Group
CLK14
Motherboard Topology
Point-to-Point
Reference Plane
Ground Referenced (Contiguous over entire
length)
Characteristic Trace Impedance (Zo)
55
Trace Width
5 mils
Trace to Space Ratio
1:2 (e.g. 5 mils trace 10 mils space)
Group Spacing
Isolation spacing from non-Clock signals =
10 mils minimum
Trace Length – A
Trace Length – B
Figure
Notes
1
± 15%
Min = 0 inches
Max = 0.50 inches
Min = 4.0 inches
Max = 8.50 inches
Series Termination Resistor (R1)
33
± 5%
Skew Requirements
Minimal skew (~ 0) between CLK14 group
and other groups, however the CLK14 group
is asynchronous to all other groups
Figure 138
Figure 138
Figure 138
NOTE: Recommended resistor values and trace lengths may change in a later revision of the design guide.
10.2.8.
CK-408 Clock Chip Decoupling
See Section 11.7.9 for details.
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10.3.
CK-408 Updates for Systems based on Intel Pentium M
Processor / Intel Celeron M Processor and Intel 855PM
Chipset
To maximize the power savings on systems based on Intel Pentium M processor / Intel Celeron M
processor and Intel 855PM chipset, additional registers have been added to the CK-408 clock generator
to allow option to tri-state the CPU[2:0] host clocks during CPU_STOP# or PWRDWN assertion. The
option to have CPU[2:0] driven (default) or tri-stated can be programmed via the serial I2C bus interface
to the CK-408 clock driver. If the tri-state feature on the CPU[2:0] signals is chosen, it is recommended
that the STP_CPU# signal from the ICH4-M drive the CK-408’s CPU_STOP# signal. Also, it is
recommended that the ICH4-M’s DPSLP# signal be connected to the DPSLP# pin of the processor and
MCH. Functionally, the ICH4-M’s STP_CPU# and DPSLP# signals are equivalent. However,
STP_CPU# is powered by the main I/O well (3.3 V) and is sent to the CK-408 whereas DPSLP# is
driven to the processor interface voltage (1.05 V).
10.4.
CK-408 PWRDWN# Signal Connections
For Intel Pentium M processor / Intel Celeron M processor based systems that support the S1M state, the
PWRDWN# input of the CK-408 clock chip is required to be driven by both the SLP_S1# and
SLP_S3# signals from the Intel 82801DBM ICH4-M, i.e. the PWRDWN# pin of the CK-408 should be
driven by the output of the logical AND of the SLP_S1# and SLP_S3# signals. This configuration best
allows CPU[2:0] to be tri-stated during S1-M or lower (numerically higher) states.
For systems that do not support S1M but do support the S3 state, the PWRDWN# input of the CK-408
clock chip should be connected to the SLP_S3# output of the ICH4-M. It is not recommended that
PWRDWN# be pulled-up to the CK-408’s 3.3-V power supply if the S3 state is the second highest,
power consuming state supported by the platform (i.e., S1M and S2 not supported). The advantage of
using SLP_S3# rather than the 3.3-V supply to qualify PWRDWN# is that it reduces the likelihood of
the CK-408 clocks driving into unpowered components and potentially damaging the clock input
buffers. Also SLP_S3# can help reduce power consumption because it will be asserted before the 3.3-V
supply will be shut off, thus minimizing the amount of time that the clocks will be left toggling.
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11.
Platform Power Delivery Guidelines
11.1.
Definitions
S0 / Full-On operation:
During Full-On operation, all components on the motherboard are powered and the system is fully
functional.
S1-M / Power-On-Suspend (POS, Mobile):
In the mobile implementation of the Power-On-Suspend state, the outputs of the clock chip stopped in
order to save power. All components remain powered but may or may not be in a low power state.
S3 / Suspend-To-RAM (STR):
In the STR state, the system state is stored in main memory and all unnecessary system logic is turned
off. Only main memory and logic required to wake the system remain powered.
S4 / Suspend-To-Disk (STD):
In the STD state, the system state is stored in non-volatile secondary storage (e.g. a hard disk) and all
unnecessary system logic is turned off. Only logic required to wake the system remain powered. Standby
power rails may or may not be powered depending on system design and the presence of AC or battery
power.
S5 / Soft-Off:
The Soft-Off state corresponds to the G2 state. Restart is only possible with the power button.
Full-Power operation:
During Full-Power operation, all components remain powered. Full-power operation includes both FullOn and the S1M (CPU Stop-Grant state).
Suspend operation:
During suspend operation, power is removed from some components on the motherboard. Intel® 855PM
chipset-based systems can be designed to support a number of suspend states such as Power-OnSuspend (S1M), Suspend-to-RAM (S3), Suspend-to-Disk (S4), and Soft-Off (S5).
Core power rail:
A power rail that is only on during full-power operation. These power rails are on when the PSON
signal is asserted to the ATX power supply.
Standby power rail:
A power rail that in on during suspend operation (these rails are also on during full-power operation).
These rails are on at all times (when the power supply is plugged into AC power). The only standby
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power rail that is distributed directly from the ATX power supply is: 5 VSB (5 V Standby). There are
other standby rails that are created with voltage regulators on the motherboard.
Derived power rail:
A derived power rail is any power rail that is generated from another power rail using an on-board
voltage regulator. For example, 3.3 VSB is usually derived (on the motherboard) from 5 VSB using a
voltage regulator.
Dual power rail:
A dual power rail is derived from different rails at different times (depending on the power state of the
system). Usually, a dual power rail is derived from a standby supply during suspend operation and
derived from a core supply during full-power operation. Note that the voltage on a dual power rail may
be misleading.
11.2.
Platform Power Requirements
The following figure shows the power delivery architecture for an example Intel 855PM chipset
platform. This power delivery architecture supports the “Instantly Available PC Design Guidelines” via
the S3 system state. To ensure that enough power is available during S3, a thorough power budget
should be completed. The power requirements should include each device’s power requirements, both in
suspend and in Full-On. The power requirements should be compared against the power budget supplied
by the power supply. Due to the requirements of main memory and PCI 3.3 Vaux (and possibly other
devices in the system), it is necessary to create a dual power rail.
The solutions given in this document are only examples. There are many power distribution methods
that achieve similar results. It is critical, when deviating from these examples, to consider the effect of
the change.
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11.2.1.
Platform Power Delivery Architectural Block Diagram
Figure 139. Platform Power Delivery Map
Intel Pentium M
processor
VCC_CORE = Processor VR
VCCP = PSB VR
PSB
400 MT/S
AGP
+V1.5S
+V3.3S
+V3.3ALWAYS
+V5S
+V12S
AGP4x (1.5v)
1.06GB/s
855PM MCH-M
VCC_MCH = MCH VR
VCCP = PSB VR
+V1.25
+V1.5S
+V1.8S
+V2.5
1.6 - 2.1 GB/s
DDR200 x 2
DDR266 x 2
+V1.25
+V2.5
13-Bit Hub
Interface
266MB/s
USB
ICH4-M
+V3.3
+V5
FWH
+V1.05S
+V1.5S
+V1.5
+V3.3S
+V1.5LAN
+V1.8S
+V3.3S
+V3.3
+V3.3LAN
+V5S
+VCC_RTC
ATA 66/100
IDE
+V3.3S
+V5S
PCI Bus
Moon2
+V5S
AC97
CardBus
LAN
+V3.3
+V3.3Always
+V5
+V3.3
+V3.3
SMC
SIO
KBC
+V3.3Always
+V3.3S
+V3.3Always
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11.3.
Voltage Supply
11.3.1.
Power Management States
Table 71. Power Management States
Signal
11.4.
SLP_S1#
SLP_S3#
SLP_S4#
SLP_S5#
+V*ALW
+V*
+V*S
Clocks
FULL ON
HIGH
HIGH
HIGH
HIGH
ON
ON
ON
ON
S1M (POS)
LOW
HIGH
HIGH
HIGH
ON
ON
ON
LOW
S3 (STR)
LOW
LOW
HIGH
HIGH
ON
ON/OFF
OFF
OFF
S4 (STD)
LOW
LOW
LOW
HIGH
ON
ON/OFF
OFF
OFF
S5 (Soft Off)
LOW
LOW
LOW
LOW
ON
ON/OFF
OFF
OFF
Intel 855PM MCH / 82801DBM ICH4-M Platform PowerUp Sequence
Figure 140 describes the power-on timing sequence for an Intel 855PM/82801DBM-based platform.
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Figure 140. Intel® 855PM/82801DBM Platform Power-Up Sequence
System
State
G3
G3
S5
S4
S3
S0
S0 state
Hub interface "CPU
Reset Complete"
message
STPCLK#,
CPUSLP#
T186
T184
Frequency
Straps
Strap Values
Normal Operation
T185
PCIRST#
T178
T181
SUS_STAT#
T177
PWROK, VGATE
T176
Vcc
SLP_S3#
T183b
T181
T18 3a
SLP_S4#
T183
SLP_S5#
Running
SUSCLK
T182
RSMRST#,
RSM_PWROK
T173
VccSus
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Table 72. Timing Sequence Parameters for Figure 140
Sym
Description
Min
Max
Units
T173
Notes
VccSus supplies active to
RSMRST# inactive
5
-
ms
139
T175b
VccLAN supplies active to
LAN_RST# active
10
-
ms
139
T176
Vcc supplies active to PWROK,
VGATE active
10
-
ms
139
T177
PWROK and VGATE active and
SYS_RESET# inactive to
SUS_STAT# inactive
32
38
RTCCLK
139
T178
SUS_STAT# inactive to PCIRST#
inactive
1
3
RTCCLK
139
T181
VccSus active to SLP_S5#,
SUS_STAT# and PCIRST# active
50
ns
139
T182/T183
RSMRST# inactive to SUSCLK
running, SLP_S5# inactive
110
ms
T183a
SLP_S5# inactive to SLP_S4#
inactive
1
2
RTCCLK
139
T183b
SLP_S4# inactive to SLP_S3#
inactive
1
2
RTCCLK
139
T184
Vcc active to STPCLK#,
CPUSLP#, STP_CPU#,
STP_PCI#, SLP_S1#, C3_STAT#
inactive, and CPU Frequency
Strap signals high
50
ns
139
T185
PWROK and VGATE active and
SYS_RESET# inactive to
SUS_STAT# inactive and CPU
Frequency Straps latched to strap
values
32
38
RTCCLK
2
139
T186
CPU Reset Complete to
Frequency Straps signals
unlatched from strap values
7
9
CLK66
3
139
1
Fig
139
NOTES:
1. If there is no RTC battery in the system, so VccRTC and the VccSus supplies come up together, the delay from
RTCRST# and the RSMRST# inactive to SUSCLK toggling may be as much as 1000 ms.
2. These transitions are clocked off the internal RTC. One RTC clock is approximately 32 µs.
3. This transition is clocked off the 66-MHz CLK66. One CLK66 is approximately 15 ns.
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11.4.1.
Intel 82801DBM ICH4-M Power Sequencing Requirements
11.4.1.1.
3.3/1.5 V and 3.3/1.8 V Power Sequencing
No power sequencing requirements exist for the associated 3.3 V/1.5 V rails or the 3.3 V/1.8 V rail of
the ICH4-M. It is generally good design practice to power up the core before or at the same time as the
other rails.
11.4.1.2.
V5REF/ 3.3 V Sequencing
V5REF is the reference voltage for 5 V tolerance on inputs to the Intel 82801DBM ICH4-M. V5REF must
be powered up before VCC3_3, or after VCC3_3 within 0.7 V. Also, V5REF must power down after VCC3_3,
or before VCC3_3 within 0.7 V. It must also power down after or simultaneous to VCC3_3. These rules
must be followed in order to ensure the proper functionality of the ICH4-M. If the rule is violated,
internal diodes will attempt to draw power sufficient to damage the diodes from the VCC3_3 rail. Figure
141 shows a sample implementation of how to satisfy the V5REF/ 3.3 V sequencing rule.
This rule also applies to the stand-by rails, but in most platforms, the VCCSUS3_3 rail is derived from the
VCCSUS5 and therefore, the VCCSUS3_3 rail will always come up after the VCCSUS5 rail. As a result,
V5REF_SUS will always be powered up before VCCSUS3_3. In platforms that do not derive the VCCSUS3_3 rail
from the VCCSUS5 rail, this rule must be comprehended in the platform design.
Figure 141. Example V5REF / 3.3 V Sequencing Circuitry
11.4.1.3.
V5REF_SUS Design Guidelines
The aforementioned rule for V5REF also applies to the V5REF_SUS input pin. However, in some platforms,
the VCCSUS3_3 rail is derived from the VCCSUS5 and therefore, the VCCSUS3_3 rail will always come up after
the VCCSUS5 rail. As a result, V5REF_SUS will always be powered up before VCCSUS3_3. In platforms where
the VCCSUS3_3 rail is not derived from the VCCSUS5 rail, the V5REF sequencing rule must be comprehended
in the platform design.
In order to meet reliability and testing requirements for the USB interface, the following design
recommendations for the V5REF_SUS pins of the ICH4-M should be followed. Changes to the USB
specification regarding continuous short conditions must be addressed. The USB 1.1 specification
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requires host controllers to withstand a continuous short between the USB 5-V connector supply to a
USB signal at the connector for an unspecified duration of time. Also, the USB 2.0 specification
requires a host controller to withstand a short between the USB 5 V connector supply to a USB signal at
the connector for 24 hours. The recommendation is to provide a 5V_ALWAYS (active S0-S5) supply to
the V5REF_SUS pins if available (see Figure 142). If such a supply rail is not readily available on the
platform, then an alternative implementation using a 3.3V_ALWAYS (active S0-S5) and a VCC5 (active
S0-S1M) or VCCSUS5 (active S0-S3) rail can be used instead (see Figure 143).
Figure 142. V5REF_SUS With 5V_ALWAYS Connection Option
+V5ALWAYS
Customer specific or
Intel recommended
USB power circuit
V5REF_SUS1
V5REF_SUS1
V5REF_SUS2
Intel
ICH4-M
ICH4-M USB D+
USB D-
USB Power (5V)
0.1uF
Customer specific or
Intel recommended
USB interface
circuits
GND
Figure 143. V5REF_SUS With 3.3V_ALWAYS and VCC5 or VCC5_SUS Connection Option
+V5S or +V5
Customer specific or
Intel recommended
USB power circuit
+V3ALWAYS
D1*
D2*
V5REF_SUS1
V5REF_SUS2
Intel
ICH
-M
ICH4-M
USB D+
4
USB D-
USB Power (5V)
0.1uF
Customer specif
specific
ic or
or
Intel recommended
USB interface
circuits
USB D+
USB D-
GND
Note: D1 and D2 are BAT54 or Equivalent Schottky Diodes
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11.4.2.
Intel 855PM MCH Power Sequencing Requirements
No Intel 855PM MCH power sequencing requirements exist for the system incorporating the Intel
855PM chipset. All MCH power rails should be stable before de-asserting reset, but the power rails can
be brought up in any order desired. Good design practice would have all MCH power rails come up as
close in time as practical, with the core voltage (1.2 V) coming up first.
Although no power sequencing requirements between any of the MCH’s rails exist, there are timing
requirements that must be met with respect to other control signals that indicate the status of platform
power rails. The 1.8-V supply rail that powers the Hub Interface of the MCH also powers the isolated,
analog supply pins for the PLLs on the processor (VCCA[3:0]) and MCH (VCCGA and VCCHA). The
1.8-V supply to the processor must be stable for a minimum of 4 s before the ICH4-M’s
CPUPWRGOOD signal can be asserted to the processor’s PWRGOOD input. Similarly, the RSTIN#
input of the MCH must be asserted by the Intel 82801DBM ICH4-M’s PCIRST# signal for a minimum
of 4 s after the 1.8-V supply is stable.
11.4.3.
DDR Power Sequencing Requirements
No DDR-SDRAM power sequencing requirements are specified during power up or power down if the
following criteria are met:
VDD and VDDQ are driven from a single power converter output
VTT is limited to 1.44 V (reflecting VDDQ(max)/2 + 50 mV VREF variation + 40 mV VTT
variation)
VREF tracks VDDQ/2
A minimum resistance of 42 (22 series resistor + 22
limits the input current from the VTT supply into any pin
parallel resistor ± 5% tolerance)
If the above criteria cannot be met by the system design, then the following Table 73 must be adhered to
during power up.
Table 73. DDR Power-Up Initialization Sequence
Voltage Description
Sequencing
Voltage Relationship to Avoid Latch-up
VDDQ
After or with VDD
< VDD + 0.3 V
VTT
After or with VDDQ
< VDDQ + 0.3 V
VREF
After or with VDDQ
< VDQ + 0.3 V
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11.5.
DDR Power Delivery Design Guidelines
The main focus of these Intel 855PM MCH guidelines is to minimize signal integrity problems and
improve the power delivery to of the MCH system memory interface and the DDR SO-DIMMs. Some
sections summarize the DDR system voltage and current requirements as of publishing for this
document. This document is not the original source for these specifications. Refer to the following
documents for the latest details on voltage and current requirements found in this design guide.
JEDEC Standard, JESD79, Double Data Rate (DDR) SDRAM Specification
Intel DDR 200 JEDEC Spec Addendum Rev 0.9 or later
Intel® 855PM Memory Controller Hub (MCH) DDR 200/266 MHz Datasheet
Figure 144. DDR Power Delivery Block Diagram
+V5
Switching
Regulator
Vin
+V2_5
Vout
Sense Adj.
10K
10K
+
SMVREF
-
+V5
Switching
Regulator
Vin
Vout
+V1_25
Sense Adj.
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11.5.1.
DDR Interface Decoupling Guidelines
The following is the recommended decoupling guidelines for the DDR system memory interface.
11.5.1.1.
Intel 855PM MCH VCCSM Decoupling Guidelines
Every Intel 855PM MCH ground and VCCSM power ball in the system memory interface should have
its own via. For the VCCSM pins of the MCH, a minimum of fifteen 0603 form factor 0.1- F high
frequency capacitors is required and must be placed within 150 mils of the MCH package. The fifteen
capacitors should be evenly distributed along the MCH DDR system memory interface and must be
placed perpendicular to the MCH with the power (2.5 V) side of the capacitors facing the MCH. The
trace from the power end of the capacitor should be as wide as possible and it must connect to a 2.5-V
power ball on the outer row of balls on the MCH. Each capacitor should have their 2.5-V via placed
directly over and connected to a separate 2.5-V copper finger, and they should be as close to the
capacitor pad as possible, within 25 mils. The ground end of the capacitors must connect to the ground
flood and to the ground plane through a via. This via should be as close to the capacitor pad as possible,
within 25 mils with as thick a trace as possible.
11.5.1.2.
DDR SO-DIMM System Memory Decoupling Guidelines
Discontinuities in the DDR signal return paths will occur when the signals transition between the
motherboard and the SO-DIMMs. To account for this ground to 2.5-V discontinuity, a minimum of nine
0603 form factor 0.1-µF high frequency bypass capacitors is required between the SO-DIMMs to help
minimize any anticipated return path discontinuities that will be created. The bypass capacitors should
be connected to 2.5 V and ground. The ground trace should connect to a via that transitions to the
ground plane. The ground via should be placed as close to the ground pad as possible. The 2.5-V trace
should connect to a via that transitions to the 2.5-V copper flood and it should connect to the closet 2.5V SO-DIMM pin on either the first or second SO-DIMM connector, with a wide trace. The capacitors’
2.5-V traces should be distributed as evenly as possible amongst the two SO-DIMMs. Finally, the 2.5-V
via should be placed as close to the 2.5-V pad as possible.
11.5.2.
2.5-V Power Delivery Guidelines
The 2.5-V power for the Intel 855PM MCH system memory interface and the DDR SO-DIMMs is
delivered around the DDR command, control, and clock signals. Special attention must be paid to the
2.5-V copper flooding to ensure proper MCH and SO-DIMM power delivery. This 2.5-V flood must
extend from the MCH 2.5-V power vias all the way to the 2.5-V DDR voltage regulator and its bulk
capacitors, located at the end of the DDR channel beyond the second SO-DIMM connector. The 2.5-V
DDR voltage regulator must connect to the 2.5-V flood with a minimum of six vias, and the SO-DIMM
connector 2.5-V pins as well as the MCH 2.5-V power vias must connect to the 2.5-V copper flood. The
copper flooding to the MCH should include at least seven fingers to allow for the routing of the DDR
signals and for optimal MCH power delivery. The copper fingers must be kept as wide as possible in
order to keep the loop inductance path from the 2.5-V voltage regulator to the MCH at a minimum. In
the areas where the copper flooding necks down around the MCH make sure to keep these neck down
lengths as short as possible. The 2.5-V copper flooding under the SO-DIMM connectors must
encompass all the SO-DIMM 2.5-V pins and must be solid except for the small areas where the clocks
are routed within the SO-DIMM pin field where they connect to their specified SO-DIMM pins.
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Additionally, a small 2.5-V copper flood shape should be placed under the MCH to encompass and
increase the copper flooding to the back row of the 2.5-V MCH pins. This flood must not be placed
under any of the DDR signals. In order to maximize the copper flooding, these signals should be kept as
short as possible in order to reduce the amount of serpentining needed in this area on the bottom layer.
Also, a minimum of 12-mil isolation spacing should be maintained between the copper flooding and the
DDR signals. Finally, the six, MCH 2.5-V high frequency decoupling capacitors located on the top
signal layer should have their 2.5-V vias placed directly over and connected to a separate 2.5-V copper
finger.
11.5.3.
DDR Reference Voltage
Table 75 through Table 77 below have grouped the voltage and current specifications together for each
the Intel 855PM MCH, memory, and termination voltages. There are seven voltages/power rails
specified here for a DDR VR system. Although, there are only two unique voltage regulators for 2.5 V
and 1.25 V nominal, each specific power rail described here has a unique specification. Described below
are the memory components themselves first (the top three listed) and the MCH requirements (next row
of 3) and finally the termination voltage and current requirements.
For convenience, tolerances are given in both % and Volts though validation should be done using the
specification exactly as it is written. The voltage specs are clearly defined under “Specification
Definition”. If this states a tolerance in terms of volts (e.g. VREF says ± 0.050 V) then that specific
voltage tolerance should be used, not a percentage of the measured value. Likewise, percentages should
be used where stated. If not stated then either way is fine.
Voltage specifications are defined as either “Absolute” or “Relative”. These are described in Table 74.
Table 74. Absolute vs. Relative Voltage Specification
Type of Specification
Description
Absolute Specification
This is a standard specification most commonly used. This means that
the voltage limits are based on a fixed nominal voltage and have a
symmetric ± tolerance added to determine the acceptable voltage
range. For example, a VDD specification does not depend on any
other voltage levels. It is simply 2.5 V ± 8%.
Relative Specification
This is a specification whose nominal value is not fixed but is relative
to or is a function of another voltage. This means that the other voltage
must be measured to know what the nominal value is and then the
symmetrical ± tolerance added to that measured value. For example, a
VREF specification depends on the actual value of VDD to determine
VDD/2 and then tolerance ± 0.050 V from this calculated value.
From the Table 75, it can be seen that only the 2.5-V supply is a fixed, absolute specification, whereas
all of the 1.25-V nominal supplies are relative to the 2.5-V supply directly or another 1.25-V supply
which is then relative to the 2.5 V supply. Due to these 1.25-V relative specifications, it becomes very
important that the 1.25 V supply can track the variations in the 2.5-V supply and respond according to
the 2.5-V rail variations. This can be implemented as shown in the block diagram in Figure 144 where
the 2.5-V output is divided in half and used to generate the 1.25 V reference into the 1.25-V VR
controller design. In this manner, the 1.25-V VR will respond proportionally to variations in the 2.5-V
supply, improving the voltage margin of the relative supply requirements and overall memory system
stability.
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Table 75. DDR SDRAM Memory Supply Voltage and Current Specification
Name
"VDD"
"VDDQ"
"VREF"
Core Supply
Voltage, Static
I/O Supply Voltage,
Static
I/O Reference Supply
Voltage, Static
Specification Definition
VDD
VDDQ
Voltage Nominal (V)
2.500
2.500
1.250
Tolerance (±%)
8.0%
8.0%
4.0%
Tolerance (±V)
0.200
0.200
0.050
Max Absolute Spec
Value (V)
2.700
2.700
1.400
((2.5V + 8%)/2) + 0.050 V
Min Absolute Spec
Value (V)
2.300
2.300
1.100
((2.5 V - 8%)/2) - 0.050 V
MAX RELATIVE SPEC
(calculated from
measured "Vdd" value)
NA
NA
(measured Vdd/2) + 0.050
V
MIN RELATIVE SPEC
(calculated from
measured "Vdd" value)
NA
NA
(measured Vdd/2) - 0.050
V
IDD (max)
IDDQ (max)
IREF (max)
5.000
0.920
0.001 (1mA)
Purpose
Absolute Maximum
Current Requirements
(A)
Intel® 855PM Chipset Platform Design Guide
Description
VREF = (Vdd/2) ± 0.050 V ((2.5 V ± 8%)/2) ± 0.050 V
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Table 76. MCH System Memory Supply Voltage and Current Specification
"VCCSM"
"SMVREF"
"VTT"=
"SMRCOMP"
Purpose
MCH DDR
Supply Voltage
(I/O), Static
MCH Reference Supply
Voltage, Static
SMRCOMP
Termination Supply
Voltage, Static
Definition
VCCSM
SMVREF = (VCCSM/2) ± 2%
VTT = ("Vref") ±
0.040 V
Voltage Nominal (V)
2.500
1.250
1.250
Tolerance (+/-%)
5.0%
2.0%
3.2%
Tolerance (+/-V)
0.125
0.025
0.040
Max Absolute Spec
Value (V)
2.625
1.339
1.440
(((2.5 V + 5%)/2) + 0.050
V) + 0.040)
Min Absolute Spec
Value (V)
2.375
1.164
1.060
(((2.5 V - 5%)/2) - 0.050
V) - 0.040)
Max Relative Spec
(calculated from
measured "VCCSM"
value)
NA
(measured VCCSM/2) + 2%
(measured Vref) +
0.04 V
Min Relative Spec
(calculated from
measured "VCCSM"
value)
NA
(measured VCCSM/2) - 2%
(measured Vref) 0.040 V
IVCCSM (max)
ISMVREF (max)
ITTRC (max)
1.900
0.00005 (50uA)
0.080 (80mA)
Name
Absolute Maximum
Current Requirements
(A)
258
Description
(((2.5 V ± 5%)/2) ± 0.050
V) ± 0.040)
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Table 77. Termination Voltage and Current Specifications
Name
"VTT"
Purpose
Termination Supply Voltage, Static
Definition
Vtt = ("Vref") ± 0.040 V
Description
(((2.5 V ± 8%)/2) ± 0.050 V) ±
0.040V
Voltage Nominal (V)
1.250
Tolerance (+/-%)
3.2%
Tolerance (+/-V)
0.040
Max Absolute Spec Value (V)
1.440
(((2.5 V + 8%)/2) + 0.050 V) +
0.040V
Min Absolute Spec Value (V)
1.060
(((2.5 V - 8%)/2) – 0.050 V) –
0.040V
Max Relative Spec (calculated
from measured "VCCSM"
value)
(Measured Vref) + 0.040 V
Min Relative Spec (calculated
from measured "VCCSM"
value)
(Measured Vref) - 0.040 V
ITT (max)
Absolute Maximum Current
Requirements (A)
11.5.3.1.
2.400
SMVREF Design Recommendations
There are two SMVREF pins on the Intel 855PM MCH that are used to set the reference voltage level
for the DDR system memory signals (SMVREF). The reference voltage must be supplied to both
SMVREF pins. The voltage level that needs to be supplied to these pins must be equal to VCCSM/2.
Note in Figure 144 that although SMVREF is generated from the 2.5-V supply, a buffer is used as well.
A buffer has also been used to provide this reference to the system for the MCH and memory. This is the
“VREF” signals to the DDR memory devices and the “SMVREF” signals (SMVREF[1:0]) to the MCH.
The reference design utilizes this buffer to provide the necessary current to these devices, which a
simple voltage divider is not capable of providing. The reference voltage supplied to SMVREF[1:0] has
the tightest tolerance in the memory system of ± 2%. Using common 1% resistors consumes 1% of this
2% tolerance. This means SMVREF must now be controlled to a 1% tolerance (i.e. be able to divide
VCCSM/2 within 1%). A simple resistor divider is not a voltage regulator and is most definitely not a
current source. Any current drawn across the resistor divider used to generate this 1.25-V reference will
cause a voltage drop across the top resistor, which distorts or biases this reference to a lower voltage.
The clarification below summarizes SMVREF.
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Table 78. Intel 855PM MCH System Memory I/O
Name
VCCSM
1
SMVREF
Purpose
MCH DDR Supply Voltage (I/O), Static MCH Reference Supply Voltage, Static
Definition
VCCSM
SMVREF = ((VCCSM ± 5%) / 2) ± 2%
Voltage Nominal (V)
2.500
1.250
Tolerance (+/-%)
± 5%
± 2%
Tolerance (±V)
0.125
0.025
Vmax(V)
2.625
1.275
Vmin(V)
2.375
1.225
IVCCSM (max)
Imax (A)
ISMVREF (max)
1.400
0.00005 (50 µA)
NOTE: Intel 855PM MCH VREF REQUIREMENTS: the MCH core is called "VCCSM" = +2.5 V ± 5%. SMVREF is
("VCCSM" ± 5%)/2 ± 2%. This means that whether the 2.5 V is 5% high or low, we need to be able to divide
that voltage by 2 within 2% accuracy. This basically means to use 1% resistors, or better.
As shown in Table 78, the max current required by the MCH for the SMVREF input is 0.00005A (50
µA). Although the current requirements for the MCH’s SMVREF inputs can be met with a resistor
divider, it is strongly recommended that a buffer be used. The use of a buffer can be shared between the
1.25-V VREF inputs of both the MCH and the DDR memory devices and may be necessary to provide
voltage regulation within 2%. Some sample calculations are shown in Table 79, it is not possible to
maintain regulation within 2% using a resistive divider without using a resistor so small that the 2.5 V
current requirement becomes prohibitive. Hence, a buffer is required due to the 10 mA current
requirement of the MCH SMVREF.
Table 79. Effects of Varying Resistor Values in the Divider Circuit
Rdivider
( )
Leakage
(A)
Rtop Vdroop
(V)
I(2.5) total = 2.5 V/2R
(A)
1
0.01
0.01
1.25
10
0.01
0.1
0.125
100
0.01
1
0.0125
1000
0.01
10
0.00125
10000
0.01
100
0.000125
100000
0.01
1000
1.25E-05
1000000
0.01
10000
1.25E-06
NOTES:
1. Rdivider: This is the resistor value selected to form the divider. Assumes both top and values are equal as
required for divide by 2.
2. Leakage: This is the amount of leakage current which needs to sourced from the 2.5-V supply, across the
divider’s top resistor (Rtop) and out to the Intel 855PM MCH SMVREF input or the DDR VREF input. This current
does not go across the bottom resistor.
3. Rtop Vdroop: This is the resulting voltage droop across Rtop as a result of the leakage current.
4. I(2.5) total = 2.5 V/2R. This is the total current through divider. This is calculated to consider the amount of
current and power used as a DC current through the divider.
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11.5.3.2.
DDR VREF Requirements
Making the same calculations for the DDR loading, results to find the max VREF load of 1 mA, a
divider is STILL NOT feasible here as the load of 1mA causes unacceptable drop across even a small
Rs, which wastes power.
Table 80. DDR VREF Calculation
Name
Vdd
Vref
Purpose
Core Supply Voltage, Static
I/O Reference Supply Voltage, Static
Vdd
Vref = (Vdd +/- 8%) / 2
VOLTAGE Nominal (V)
2.500 (± 8%)
1.250
TOLERANCE (+/-V)
0.200
0.050
Vmax(V)
2.700
1.300
Vmin(V)
2.300
1.200
IDD
IREF
5.000
0.001
Design Guide
NOTE:
The DDR core is called "Vdd" =+2.5 V ± 8% (= ± 0.2 V). VREF is ("Vdd" ± 8%)/2 ± 50 mV. This means that
whether the 2.5 V is 8% high or low, Platform designers need to be able to divide that voltage by 2 within an
accuracy of 50 mV. This basically means to use 1% resistors, or better.
Table 81. Reference Distortion Due to Load Current
R( )
I(A)
Vdroop(V)
I(2.5) total=2.5 V/2R(A)
1
0.001
0.001
1.25
10
0.001
0.01
0.125
100
0.001
0.1
0.0125
1000
0.001
1
0.00125
10000
0.001
10
0.000125
100000
0.001
100
1.25E-05
1000000
0.001
1000
1.25E-06
NOTE:
As for the MCH, a calculation can be made for the DDR. This shows that even with the slight load of 1 mA by
the DDR it is still not feasible to use a simple resistor divider. Using the max leakage specs provided today
and trying to maintain an error of less than 1% (12.5 mV) one needs to decrease the resistor values such
that the current just to source the divider becomes unacceptable. A divider alone does not become an
acceptable solution until current requirements are in the 100-µA range. Today, it is not possible to guarantee
this type of current requirement for these applications. Therefore, the use of a buffer is highly recommended
for these reference voltage requirements.
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11.5.4.
DDR SMRCOMP Resistive Compensation
The Intel 855PM MCH requires a system memory compensation resistor, SMRCOMP, to adjust buffer
characteristics to specific board and operation environment characteristics. Refer to the Intel® 855PM
Memory Controller Hub (MCH) DDR 200/266 MHz Datasheet for details on resistive compensation.
Tie the SMRCOMP pin of the MCH to a 30.1- ± 1% pull-up resistor to the DDR termination voltage
(1.25 V). Also, one 0603 0.1-µF decoupling capacitor to ground should be used. Place the resistor and
capacitor within 1.0 inch of the MCH. The decoupling capacitor must be placed on the VTT powered
side of the SMRCOMP resistor. The SMRCOMP signal and VTT trace should be routed with as wide a
trace as possible. It should be a minimum of 12 mils wide and be isolated from other signals with a
minimum of 10 mils spacing.
11.5.5.
DDR VTT Termination
The recommended topology for DDR-SDRAM Data, Control, and Command signal groups requires that
all these signals to be terminated to a 1.25-V source, VTT, at the end of the memory channel opposite
the Intel 855PM MCH. It is recommended that VTT be generated from the same source as that used for
VCCSM, and do not be shared with the MCH and DDR SMVREF. SMVREF has a much tighter
tolerance and VTT can vary more easily depending on signal states. A solid 1.25-V termination island
should be used to for this purpose. The VTT termination island should be placed on the top signal layer,
just beyond the last SO-DIMM connector and must be at least 50 mils wide. The Data and Command
signals should be terminated using one resistor per signal. Resistor packs and ± 5% tolerant resistors are
acceptable for this application. Only signals from the same DDR signal group can share a resistor pack.
See Section 11.5.1 and 11.7.1 for details on high frequency and bulk decoupling requirements.
11.5.6.
DDR SMRCOMP, SMVREF, VTT 1.25-V Supply Disable in
S3/Suspend
The DDR interface of the Intel 855PM MCH requires that several 1.25-V voltage sources be supplied to
different parts the system memory interface for proper operation. In addition to providing the DDR VTT
termination voltage at the end of the DDR bus for the Data, Control, and Command signal groups, 1.25V supplies are also used to provide the reference voltages SMVREF of the MCH, the VREF of the DDR
memory devices on the SO-DIMMs, and the termination voltage of the 30.1 ± 1% SMRCOMP
resistor of the MCH.
SMRCOMP and VTT 1.25-V supplies can be disabled during the S3 suspend state to further save power
on the platform. This is possible because the MCH does not require resistive compensation during
suspend. However, the 2.5-V VCCSM power pins of the MCH, the SMVREF pin of the MCH, and the
VDD power pins of the DDR memory devices are required to be on in S3 state.
Note: Some DDR memory devices require a valid reference voltage during suspend. It is the responsibility of
the system designer to ensure that requirements of the DDR memory devices are met. Intel recommends
following VREF design on Intel CRB.
11.5.6.1.
VTT Rail Power Down Sequencing During Suspend
The VTT termination voltage for the DDR bus must not be turned off until all populated rows of
memory have been placed into power down mode through the deassertion of the SCKE signals. Once all
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rows of memory are powered off, the VTT termination voltage can be removed. During entry into
suspend and during suspend, VTT must not glitch.
The voltage supplied to VREF (see Notes in 11.5.6), and SMRCOMP can be removed once all rows of
memory are powered off and SCKE must not glitch during entry into suspend and during suspend.
Consult JEDEC Standard, JESD79, Double Data Rate (DDR) SDRAM Specification for more details.
11.5.6.2.
VTT Rail Power Up Sequencing During Resume
During resume from the S3 state, the reverse sequencing of the power rails and control signals must
happen to ensure a smooth exit from suspend. The VTT termination voltage must be supplied and steady
for a minimum of 10 ms before the system begins exit from suspend. VTT must not glitch during
resume.
VREF (see NOTES in 11.5.6)), and SMRCOMP also need to be supplied and valid before the assertion
of the SCKE signals. These reference voltages and resistive compensation are necessary in order for the
Intel 855PM MCH and the memory devices to recognize the valid assertion of SCKE to a logic ‘1’.
SCKE must not glitch during resume and must rise monotonically.
VTT and VREF to the SO-DIMMs and SMVREF and SMRCOMP to the MCH must all be up and
stable for a minimum of 10 ms before the deassertion of PCIRST#.
Consult JEDEC Standard, JESD79, Double Data Rate (DDR) SDRAM Specification for more details.
11.6.
Clock Driver Power Delivery Guidelines
Special care must be taken to provide a quiet VDDA supply to the Ref VDD, VDDA, and the 48 MHz
VDD. These VDDA signals are especially sensitive to switching noise induced by the other VDDs on
the cock chip. They are also sensitive to switching noise generated elsewhere in the system such as the
CPU VRM. The CLC pi-filter should be designed to provide the best reasonable isolation. It is
recommended that a solid ground plane be underneath the clock chip on Layer 2 (assuming top trace is
Layer 1). Intel also recommends that a ground flood be placed directly under the clock chip to provide a
low impedance connection for the VSS pins.
For ALL power connections to planes, decoupling capacitors and vias, the MAXIMUM trace width
allowable and shortest possible lengths should be used to ensure lowest possible inductance. The
decoupling capacitors should be connected as shown in the illustration taking care to connect the VDD
pins directly to the VDD side of the capacitors. However, the VSS pins should not be connected directly
to the VSS side of the capacitors. Instead they should be connected to the ground flood under the part
that is via’ed to the ground plane. This is done to avoid VDD glitches propagating out, getting coupled
through the decoupling capacitors to the VSS pins. This method has been shown to provide the best
clock performance.
The ground flood should be via’ed through to the ground plane with no less than 12-16 vias under the
part. It should be well connected. For all power connections, heavy duty and/or dual vias should be
used. It is imperative that the standard signal vias and small traces not be used for connecting
decoupling capacitors and ground floods to the power and ground planes. VDDA should be generated
by using a CLC pi-filter. This VDDA should be connected to the VDD side of the three capacitors that
require it using a hefty trace on the top layer. This trace should be routed from the CLC pi-filter using a
star topology.
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Figure 145. Decoupling Capacitors Placement and Connectivity
VddA
Vdd
XTAL_In
XTAL_Out
Vss
C1
Vs
s
1
56
2
55
3
54
4
Vdd
PCIF 1
6
51
CPU
/0
PCIF 2
7
50
Vdd
8
49
CPU
1
48
CPU
/1
9
PCI 0
10
PCI 1
11
46
12
Vss
C5
45
CPU
2
CPU
/2
Vdd
14
43
Mult
0
42
IRE
F
15
PCI 4
16
PCI 5
17
PCI 6
18
Vdd
19
Vss
20
21
41
40
39
38
37
36
S2
US
B
48
MHz
DO
T
48
MHz
Vss
48 MHz
3V66_1 /
VCH
23
34
PCI_Sto
p#
24
33
3V66
_0
25
SCL
Vd
32 Vss
Vdd
Kd
Vss
A
27
28
31
VddA
Vdd
48 MHz
35
26
Vdd
Vss Iref
22
Vdd
A
Vtt_Pwr
gd #
Vs
s
Gr
ou
nd
Flo
od
Vss
Vdd
44
Vss
Vdd
Vss
13
PWRD
WN#
264
47
C6
Vdd
PCI 3
66Buff0
/ 3V66_2
66Buf
/f1
3V66_
66Buf
3
/f2
3V66_
4
66In /
3V66_5
VddA
CPU_Sto
p#
CPU
0
Vdd
Vss
53
52
PCI 2
C3
Vss Plane Vias
S0
5
Vdd
Vss
S1
PCIF 0
Vss
C2
REF
0
Vs
s
30
SCL
K
29
SDAT
A
C4
Vss
Vdd
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11.7.
Decoupling Recommendations
Intel recommends proper design and layout of the system board bulk and high frequency decoupling
capacitor solution to meet the transient tolerances for each component. To meet the component transient
load steps, it is necessary to properly place bulk and high frequency capacitors close to the component
power and ground pins.
11.7.1.
Processor Decoupling Guidelines
See Section 5.9.2 for details on recommended VCC-CORE decoupling solutions.
11.7.2.
Intel 855PM MCH Decoupling Guidelines
Table 82. Decoupling Requirements for the Intel 855PM MCH
Pin
11.7.3.
Decoupling
Requirements
Decoupling Type (Pin type)
Decoupling Placement
VCC_MCH
See Section 5.9.5
Decoupling Cap: See Table 22
Place near balls: See Figure 69
VCC1_5
See Section 7.3.4
Decoupling Cap: See Section
7.3.4
Place near balls: See Section
7.3.4
VCC1_8
(2) 0.1 µF
Decoupling Cap: See Section 8.5
Place near balls: See Section 8.5
VCCGA,
VCCHA
(2) 10 µF
10 nF
Decoupling Cap: See Section 5.2
Place near balls: T13, T17; See
Section 5.2
VCCSM
See Section
11.5.1.1
Decoupling Cap: See Section
11.5.1.1
Place near balls: See Section
11.5.1
VCCP
See Section 5.9.4
Decoupling Cap: See Table 21
Place near balls: See Figure 64 &
Figure 66
(2)
Intel 82801DBM ICH4-M Decoupling Guidelines
The Intel 82801DBM ICH4-M is capable of generating large current swings when switching between
logic high and logic low. This condition could cause the component voltage rails to drop below
specified limits. To avoid this type of situation, ensure that the appropriate amount of bulk capacitance
is added in parallel to the voltage input pins. Intel recommends that the developer use the amount of
decoupling capacitors specified in
Table 83 to ensure the component maintains stable supply voltages. The capacitors should be placed as
close to the package as possible (100 mils nominal). Rotate caps that set over power planes so that the
loop inductance is minimized (see Figure 146). The basic theory for minimizing loop inductance is to
consider which voltage is on Layer 2 (power or ground) and spin the decoupling cap with the opposite
voltage towards the BGA (Ball Grid Array). This greatly minimizes the total loop inductance. Intel
recommends that for prototype board designs, the designer should include pads for extra power plane
decoupling caps.
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Figure 146. Minimized Loop Inductance Example
Copper
Plane
Under BGA
Trace
connecting
Pad to Via
Decoupling
Cap
BGA
BALL
GND
Ball
BGA
S
PWR
Ball
BGA
BALL
Layer 1
4.5 mils nominal
Layer 2
PWR
PAD
Layer 3
GND
GND
Layer 4
48 mils nominal
VIA
Current Flow to Decoupling Cap
Table 83. Decoupling Requirements for the Intel 82801DBM ICH4-M
Pin
Decoupling
Requirements
Decoupling Type (Pin type)
Decoupling Placement
VCC3_3
(6) 0.1 µF
Decoupling Cap (Vss)
Place near balls: A4, A1, H1, T1,
AC10, and AC18
VCCSUS3_3
(2) 0.1 µF
Decoupling Cap (Vss)
Place near balls: A22 and AC5
VCCLAN3_3
(2) 0.1 µF
Decoupling Cap (Vss)
Place near balls: E9 and F9
V_CPU_IO
(1) 0.1 µF
Decoupling Cap (Vcc)
Place near ball: AA23
VCC1_5
(2) 0.1 µF
Decoupling Cap (Vss)
Place near balls: K23 and C23
VCCSUS1_5
(2) 0.1 µF
Decoupling Cap (Vss)
Place near balls: A16 and AC1
VCCLAN1_5
(2) 0.1 µF
Decoupling Cap (Vss)
Place near balls: F6 and F7
V5REF
(1) 0.1 µF
Decoupling Cap (Vcc)
Place near ball: E7
V5REF_SUS
(1) 0.1 µF
Decoupling Cap (Vss)
Place near ball: A16
VCCRTC
(1) 0.1 µF
Decoupling Cap (Vcc)
Place near ball: AB5
VCCHI
(2) 0.1 µF
Decoupling Cap (Vss)
Place near balls: T23 and N23
Decoupling Cap (Vcc)
Place near ball: C22
VCCPLL
(1) 0.1 µF
(1) 0.01 µF
NOTES:
1. Capacitors should be placed less than 100 mils from the package.
2. ICH4-M balls listed in the “Decoupling Placement” guidelines column may not necessarily correlate to a VCC
power ball and may include signal balls from different interfaces.
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11.7.4.
DDR VTT High Frequency and Bulk Decoupling
The VTT Island must be decoupled using high-speed bypass capacitors, one 0603, 0.1-µF capacitor per
two DDR signals. These decoupling capacitors connect directly to the VTT island and to ground, and
must be spread out across the termination island so that all the parallel termination resistors are near
high frequency capacitors. The capacitor ground via should be as close to the capacitor pad as possible,
within 25 mils with as thick a trace as possible. The ground end of the capacitors must connect to the
ground flood on Layer 2 and to the ground plane on Layer 3 through a via. Finally, the distance from
any DDR termination resistor pin to a VTT capacitor pin must not exceed more then 100 mils.
11.7.5.
AGP Decoupling
See Section 7.3.4 for details.
11.7.6.
Hub Interface Decoupling
See Section 8.5 for details.
11.7.7.
FWH Decoupling
A 0.1-µF capacitor should be placed between the VCC supply pins and the VSS ground pins to decouple
high frequency noise, which may affect the programmability of the device. Additionally, a 4.7-µF
capacitor should be placed between the VCC supply pins and the VSS ground pins to decouple low
frequency noise. The capacitors should be placed no further than 390 mils from the VCC supply pins.
11.7.8.
General LAN Decoupling
All VCC pins should be connected to the same power supply.
All VSS pins should be connected to the same ground plane.
Four to six decoupling capacitors, including two 4.7-µF capacitors are recommended
Place decoupling as close as possible to power pins.
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11.7.9.
CK-408 Clock Driver Decoupling
The decoupling requirements for a CK-408 compliant clock synthesizer are often dependent on vendor
design and implementation. The appropriate decoupling guidelines in terms of type, quantity, form
factor, and usage of decoupling capacitors should come from the respective clock synthesizer
component vendor.
If clock synthesizer specific decoupling guidelines from a vendor are not available, the general
guidelines below can be used.
The decoupling caps should be connected taking care to connect the VDD pins directly to the VDD side
of the caps. However, the VSS pins should not be connected directly to the VSS side of the caps.
Instead, they should be connected to the ground flood under the part that is via’ed to the ground plane.
This is done to avoid VDD glitches propagating out and getting coupled through the decoupling caps to
the VSS pins. This method has been shown to provide the best clock performance.
The decoupling requirements for a CK-408 compliant clock synthesizer are as follows:
One 10-µF bulk decoupling cap in a 1206 package placed close to the VDD generation circuitry.
Six 0.1-µF high frequency decoupling caps in a 0603 package placed close to the VDD pins on the
CK-408.
Three 0.1-µF high frequency decoupling caps in a 0603 package placed close to the VDDA pins on
the CK-408.
One 10-µF bulk decoupling cap in a 1206 package placed close to the VDDA generation circuitry
11.8.
Intel 855PM MCH Power Consumption Numbers
The following table shows the Intel 855PM MCH power consumption estimates.
Table 84. Intel 855PM MCH Power Consumption Estimates
Power Plane
Maximum Power Consumption
S0
268
S1M
S3
S4/S5
G3
VCCP (1.05 V)
2.4 A
36 mA
N/A
N/A
N/A
VCC-MCH (1.2 V Core)
1.65 A
66 mA
N/A
N/A
N/A
VCC1_5 (AGP)
370 mA
4 mA
N/A
N/A
N/A
VCC1_8 (HI 1.0)
200 mA
43 mA
N/A
N/A
N/A
VCCA (PLL 1.8 V)
N/A
N/A
N/A
N/A
N/A
VCCSM (DDR 2.5 V)
1.9 A
< 1 mA
< 1 mA
N/A
N/A
SMVREF
50 A
N/A
0 mA
N/A
N/A
SMRCOMP
80 mA
N/A
0 mA
N/A
N/A
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11.9.
Intel 82801DBM ICH4-M Power Consumption Numbers
The following table shows the Intel 82801DBM ICH4-M power consumption estimates.
Table 85. Intel 82801DBM ICH4-M Power Consumption Estimates
Power Plane
Maximum Power Consumption
S0
Vcc1_5 Core
S1M
S3
S4/S5
G3
550 mA
94 mA
N/A
N/A
N/A
528 mA
1 mA
N/A
N/A
N/A
VccLAN1_5 (S0/D0 )
15.5 mA
N/A
N/A
N/A
N/A
VccLAN1_5 (D3 )
13 mA
13 mA
4 mA
4 mA
N/A
VccLAN3_3 (S0/D0 )
9.2 mA
N/A
N/A
N/A
N/A
VccLAN3_3 (D3 )
2.1 mA
2.1 mA
2.1 mA
2.1 mA
N/A
VccSUS1_5
1
67.5 mA
35.7 mA
8.4 mA
8.4 mA
N/A
VccSUS3_3
1
165 mA
0.3 mA
0.09 mA
0.08 mA
N/A
VCCRTC
N/A
N/A
N/A
N/A
5 A
V_CPU_IO
2.5 mA
2.5 mA
N/A
N/A
N/A
VccHI (HI 1.0 – 1.8 V)
132 mA
132 mA
N/A
0 mA
N/A
V5REF
10 µA
10 µA
N/A
N/A
N/A
V5REF_SUS
10 µA
10 µA
10 µA
10 µA
N/A
Vcc3_3 I/O
2
2
2
2
NOTES:
1. This number assumes six High-speed USB ports transmitting and receiving.
2. D0 LAN state collected under 100 Mbps stress testing. D3 LAN state assumes connection to a 100-Mbit network.
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11.10.
Thermal Design Power
The thermal design power is the estimated maximum possible expected power generated in a component
by a realistic application. It is based on extrapolations in both hardware and software technology over
the life of the product. It does not represent the expected power generated by a power virus. The thermal
design power number for the Intel 855PM MCH and Intel 82801DBM ICH4-M are listed below.
Table 86. Intel 855PM MCH Component Thermal Design Power
Intel 855PM MCH - Thermal Design Power Consumption Dissipation (estimated)
Intel 855PM MCH
1.8 W (maximum)
Table 87. Intel 82801DBM ICH4-M Component Thermal Design Power
Intel 82801DBM ICH4-M - Thermal Design Power Consumption Dissipation (estimated)
Intel 82801DBM ICH4-M
270
2.0 W (maximum)
Intel® 855PM Chipset Platform Design Guide
Intel® PRO/Wireless 2100 and Bluetooth Design Requirements
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12.
Intel® PRO/Wireless 2100 and
Bluetooth Design Requirements
This section describes the design requirements needed to interface an Intel 802.11 wireless LAN
device (Intel® PRO/Wireless 2100 family) to a Bluetooth module of choice that supports Intel’s
Wireless Coexistence System (WCS) specification. Other requirements for supporting Intel
PRO/Wireless and Bluetooth features are also addressed. The following topics are covered in this
section:
1. PCB interface requirements
2. DC power requirements for Bluetooth
3. Selective Suspend support requirements
4. Wake on Bluetooth support requirements
5. RF Disable support requirements for Intel PRO/Wireless and Bluetooth Devices
12.1.
PCB Interface Requirements
Two PCB traces shall be used to carry channel number and clock signals between Bluetooth and Intel
PRO/Wireless 2100. Although these traces do not need to match any length, width or impedance
constraints a typical width of 5 mils and spacing of 5 mils is recommended. Pin # 43 of the mPCI
connector needs to be routed to the Channel_Data signal of the Bluetooth module. Pin # 36 of the mPCI
connector needs to be routed to the Channel_Clock signal of the Bluetooth module. The Channel_Data
and Channel_Clock pins on the Bluetooth module are vendor specific. Please refer to the corresponding
Bluetooth module vendor for this information. The traces between Intel PRO/Wireless 2100 and
Bluetooth are a point-to-point connection and do not require any intervening components.
Figure 147. Recommended Topology for Coexistence Traces
12.2.
DC Power Requirements for Bluetooth
Voltage levels to power Bluetooth modules are vendor specific. Typical voltage requirement to power
Bluetooth module is 3.3Vwith 2% tolerance. This source may be derived from any power rail
available on the platform capable of providing the Bluetooth module power requirements. Please note
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Intel® PRO/Wireless 2100 and Bluetooth Design Requirements
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that if implementing Wake on Bluetooth or Selective Suspend an appropriate power rail should be
selected. See Section 12.3 and section 12.4 for details. The Fishhook reference board provides
multiple power delivery solutions for the Bluetooth module including a 3.3-V source from the CRB
and a 3.3-V source derived from the 5-V USB power rail.
12.3.
Selective Suspend Support
USB based Bluetooth modules that plan to support the Microsoft Selective Suspend feature must be
self-powered. Selective Suspend allows the processor to enter the C3/C4 state with the presence of a
USB based Bluetooth module. The USB power rail is not a sufficient source for a self-powered
module. The power rail must be always on in system states S0, S1 and S2 for a self-powered device.
Generally it is recommended for all internal USB devices (in this case the Bluetooth module) to selfpowered for best power efficiency and to be capable of waking up the system. For more information
refer to:
“Power saving of using USB selective Suspend Support” published in
http://www.intel.com/design/mobile/platform/downloads/Power_Saving_USB_Selective_Suspend.pdf
12.4.
Wake on Bluetooth Requirements
WoBT (Wake on Bluetooth) provides a method for the Bluetooth module to wake the system upon
Bluetooth device activity. This functionality is similar to Wake on LAN. Support for WoBT requires
the device to be self-powered and the power rail to be always on in system states S0-S4. The same
signal used for WOL (Wake on LAN) is planned for use by the WoBT signal. This is a point to point
interface and does not require any interface logic. There are no trace length or spacing requirements
for this low speed signal.
12.5.
RF Disable Support Requirements for Intel
PRO/Wireless 2100 and Bluetooth Devices
The RF Disable interface to the Intel PRO/Wireless 2100 module occurs via pin 13 of the mini-PCI
connector. This interface provides support to disable the Intel PRO/Wireless 2100 radio through
methods including, but not limited to, an external mechanical switch or button on the notebook or
through an embedded controller. This is an active low signal which provides the ability to disable the
RF portions of Intel PRO/Wireless 2100. The Intel PRO/Wireless 2100 radio remains disabled until
RF_KILL# is unasserted.
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Reserved, NC, and Test Signals
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13.
Reserved, NC, and Test Signals
The Intel Pentium M processor, Intel Celeron M and Intel 855PM MCH may have signals listed as
“RSVD”, “NC”, or other name whose functionality is Intel reserved. The following section contains
recommendations on how these Intel reserved signals on the processor or MCH should be handled.
13.1.
Intel Pentium M Processor and Intel Celeron M RSVD
Signals
The Intel Pentium M processor / Intel Celeron M processor has a total of three TEST and seven RSVD
signals that are Intel reserved in the pin-map. All other RSVD signals are to be left unconnected but
should have access to open routing channels for possible future use.
The location of the Intel reserved signals in the Intel Pentium M processor / Intel Celeron M processor
pin-map is listed in Table 88.
Table 88. Processor RSVD and TEST Signal Pin-Map Locations
Signal Name
Ball Name
RSVD
AF7
RSVD
B2
RSVD
C3
RSVD
C14
RSVD
E26
RSVD
G1
RSVD
AC1
TEST1
C5
TEST2
F23
TEST3
C16
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13.2.
Intel 855PM MCH RSVD Signals
The Intel 855PM MCH has a total of nine RSVD and two NC signals that are Intel reserved in the pinmap. The recommendation is to provide test points for all RSVD signals for possible future use. All NC
signals should be left as no connects. The 1-k resistor should not be populated by default. The location
of the Intel reserved signals in the MCH pin-map is listed in Table 89.
The MCH’s TESTIN# signal is used manufacturing and board level test purposes only. TESTIN# is an
input signal and has an integrated pull-up. For normal operation, it can be left unconnected.
Table 89. MCH RSVD and NC Signal Pin-Map Locations
Signal Name
274
Ball Name
NC
AD26
NC
AD27
RSVD
G2
RSVD
G3
RSVD
G9
RSVD
G10
RSVD
G16
RSVD
G22
RSVD
H3
RSVD
H7
RSVD
H27
TESTIN#
H26
Intel® 855PM Chipset Platform Design Guide
Platform Design Checklist
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14.
Platform Design Checklist
The following checklist provides design recommendations and guidance for the Intel Pentium M
processor / Intel Celeron M processor systems with the Intel 855PM chipset platform. It should be used
to ensure that design recommendations in this design guide have been followed prior to schematic
reviews. However, this is not a complete list and does not contain detailed layout information.
Note: Unless otherwise specified the default tolerance on resistors is ± 5%. Also note that the (S) reference
after power rails such as VCC3_3 (S) indicates a switched rail þu one that is powered off during S3-S5.
14.1.
General Information
The following section should be filled out by the OEM or Intel Field Representative.
Processor (Intel Pentium M Processor )
Processor Min Frequency targeted for this platform
Processor/Max Frequency targeted for this platform
Voltage Regulator Solution
Part#/Vendor:
Target ICC(max):
Internal Graphics Used?
External Graphics AGP Graphics
Part#/Vendor:
Target Thermal Envelope (Watts)
LOM or mini-PCI LAN?
Target FCS (First Customer Ship) Date
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14.2.
Customer Implementation
Fill in Schematic Name of Voltage Rails on Mark Boxes of when Rails are powered on.
Name of Rail
14.3.
On S0-S1
On S3
On S4
On S5
Design Checklist Implementation
The voltage rail designations in this design checklist were intended to be as general as possible. The
following table describes the equivalent voltage rails in the Intel CRB schematics attached in this design
guide.
Checklist Rail
Intel CRB Rail
On S0-S1
Vcc1_2[Vcc_mch]
V1.2S_MCH
X
Vcc1_25[DDR_Vtt]
V1.25S
X
Vcc1_5
V1.5S, 1.5S_AGP
X
VccSus1_5
V1.5, V1.5ALWAYS
V1_5ALWAYS
Vcc1_8
VccSus2_5
V2.5_MCH, V2.5DDR
X
Vcc3_3
V3S, V3.3S_ICH
X
4
On S3
On S4
On S5
X
X
1,3
1,3
See VccSus1_5
X
X
X
X
V1-8S
X
X
VccSus3_3
V3, V3ALWAYS
X
X
1, 3
1, 3
VccSus3_3LAN
V3.3_LAN
X
2
2
2
V3ALWAYS
See VccSus3_3
X
X
X
X
Vcc5
V5S
X
X
1
1
X
X
X
VccSus5
V5
X
Vcc12
V12S
X
VccRTC
VccRTC
X
VCCP
X
Vcc_core
X
VCCP
5
VCC[Vcc_Core]
NOTES:
1. A rail powered in Sx is dependent on implementation.
2. A VccLANx rail powered on in Sx is dependent on implementation.
3. A VxALWAYS rail can be the SUS rail depending on implementation.
4. Vcc1_25 is the 1.25V VTT termination voltage for DDR. This power rail can be OFF during S3.
5. VCCP is the 1.05V FSB signaling level of the CPU, MCH, and ICH4-M (legacy signal). Also used for the ITP700
FLEX debug port, if used.
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14.4.
Intel Pentium M Processor and Intel Celeron M
Processor
14.4.1.
Resistor Recommendations
1
Intel Pentium M/Intel Celeron M Processor – Resistor Recommendations
Pin Name
System
Series Termination
Resistor (
Pull up/Pull
down
Notes
9
Point-to-point connection to ICH4-M.
A20M#,
IGNNE#,
LINT0/INTR,
LINT1/NMI,
SLP#, SMI#,
STPCLK#
BPM[3:0]#
If ITP700FLEX Is Used:
See Section 14.4.2.1.
If ITP Interposer Is Used:
Leave the signals as NC (No Connect).
If ITP Not Supported:
Leave the signals as NC (No Connect).
COMP[0],
COMP[2]
Pull down to GND
27.4
± 1%
Resistor placed within 0.5” of CPU pin
via a Zo = 27.4 trace. Trace should
be at least 25 mils (>50 mils preferred)
away from any other toggling signal.
See section 4.1.8 placement and
routing guidelines.
COMP[1],
COMP[3]
Pull down to GND
54.9
± 1%
Resistor placed within 0.5” of CPU pin
via a Zo = 55 trace. Trace should be
at least 25 mils (>50 mils preferred)
away from any other toggling signal.
See section 4.1.8 placement and
routing guidelines.
DBR#
If ITP700FLEX Is Used:
Leave this signal as NC (No Connect).
If ITP Interposer is Used:
See Section 14.4.2.2
If ITP Not Supported:
Leave this signal as NC (No Connect).
DPSLP#
Daisy chain topology from ICH4-M to
CPU to MCH. DPSLP# should fork at
the pin of the CPU. T-split routing
should not be used.
See section 4.1.4.1.5 for more details.
FERR#
Pull up to VCCP
56
Intel® 855PM Chipset Platform Design Guide
56
FERR# is a 1.05V tolerant signal and
voltage translation logic may be
required. Parallel termination resistor
should be placed near the ICH4-M or
system receiver. Series resistor should
277
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1
Intel Pentium M/Intel Celeron M Processor – Resistor Recommendations
Pin Name
System
Series Termination
Resistor (
Pull up/Pull
down
Notes
9
be placed between the receiver and
termination resistor. Series resistor
should have no stub when connecting
to the FERR# trace from the CPU.
See Section 4.1.4.1.2 for more details.
GTLREF
(pin AD26)
1k
± 1%
(top)
Voltage divider placed within 0.5” of
CPU pin via a Zo = 55 trace. No
decoupling should be placed on the pin.
2 k ± 1%
(bottom)
IERR#
Pull up to VCCP
56
See Figure 148 and section 4.1.7 for
more details.
56
IERR# is a 1.05 V tolerant signal and
voltage translation logic may be
required.
If IERR# Is NOT Used:
56
pull-up to VCCP is required.
If IERR# Is Used:
Parallel termination resistor should be
placed near the system receiver. Series
resistor should be placed between the
receiver and termination resistor. Series
resistor should have no stub when
connecting to IERR# trace from the
CPU.
See Section 4.1.4.1.1 for more details.
INIT#
See Notes
R1 = 1.3 k
R2 = 330
Rs = 330
INIT# is T-split from the ICH4-M to the
CPU and FWH. A voltage translation
circuit is required for the use with the
Intel 82802AB/AC FWH (see Figure
149).
The voltage translation circuit shown
assumes the receiver uses a 3.3 V I/O
supply voltage.
For all other firmware devices, proper
voltage translation should be ensured.
See section 4.1.4.1.7 for more details.
PRDY#, PREQ#
If ITP700FLEX Is Used:
See Section 14.4.2.1.
If ITP Interposer Is Used:
Leave the signals as NC (No Connect).
If ITP Not Supported:
Leave the signals as NC (No Connect).
PROCHOT#
Pull up to VCCP
56
PROCHOT# is a 1.05 V tolerant signal
and voltage translation logic may be
required.
The ICH4-M’s THRM# signal should not
be driven by PROCHOT#.
If Voltage Translation Is Not
Required:
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1
Intel Pentium M/Intel Celeron M Processor – Resistor Recommendations
Pin Name
System
Series Termination
Resistor (
Pull up/Pull
down
Notes
9
Point-to-point connection to system
receiver.
If Voltage Translation Is Required:
Driver isolation resistor should be
placed at the beginning of the T-split to
the system receiver.
See
Figure 151 and Section 4.1.4.1.3 for
details.
PWRGOOD
Pull up to VCCP
330
Point-to-point connection to ICH4-M.
Parallel termination resistor routing
should fork at the pin of the CPU and Tsplit routing should not be used.
RESET#
Pull up to VCCP
(ITP700FLEX
only)
54.9
± 1%
(ITP700FLEX
only)
22.6
± 1%
(ITP700FLEX only)
If ITP700FLEX Is Not Used:
Point-to-point connection to MCH.
If ITP700FLEX Is Used:
RESET# forks out from the MCH to the
st
CPU and ITP700FLEX. 1 branch
connects the MCH point-to-point to the
CPU.
nd
2 branch needs to be pulled up to
VCCP through a 54.9
± 1% resistor
placed close to the ITP700FLEX. The
pull up resistor should be placed within
nd
12” of the MCH. 2 branch should
connect to the ITP700FLEX through a
22.6 ± 1% series dampening resistor
placed next to the 54.9 ± 1% pull up.
Series resistor should also be placed
within 0.5” of the ITP700FLEX.
See Section 4.1.5 for more details
RSVD
(pin AC1, E26,
G1)
RSVD
(Pin AF7, B2,
C3, C14)
These 3 signals were previously named
GTLREF[3:1].
These 3 signals are currently classified
as RSVD signals. Leave the signals as
NC (No Connect).
Design Options:
1. Route to test point (recommended).
OR
2. Leave unconnected with access to
open routing channels for possible
future use.
TCK
If ITP700FLEX Is Used:
See Section 14.4.2.1.
If ITP Interposer Is Used:
See Section 14.4.2.2.
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279
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1
Intel Pentium M/Intel Celeron M Processor – Resistor Recommendations
Pin Name
System
Series Termination
Resistor (
Pull up/Pull
down
Notes
9
If ITP Not Supported:
See Section 14.4.2.3.
TDI
If ITP700FLEX Is Used:
See Section 14.4.2.1.
If ITP Interposer Is Used:
See Section 14.4.2.2.
If ITP Not Supported:
See Section 14.4.2.3.
TDO
If ITP700FLEX Is Used:
See Section 14.4.2.1.
If ITP Interposer Is Used:
See Section 14.4.2.2.
If ITP Not Supported:
See Section 14.4.2.3.
TEST[3:1]
(pin C16, F23,
C5)
Pull down to GND
THERMTRIP#
Pull up to VCCP
1k
Stuffing option for 1K pull down to
GND should be provided for testing
purposes. For normal operation, resistor
should be No Stuff.
(Default: No Stuff)
56
56
THERMTRIP# is a 1.05 V tolerant
signal and voltage translation logic may
be required.
Parallel termination resistor should be
placed near the ICH4-M or system
receiver.
Series resistor should be placed
between the receiver and termination
resistor. Series resistor should have no
stub when connecting to the
THERMTRIP# trace from the CPU.
See section 4.1.4.1.2 for more details.
TMS
If ITP700FLEX Is Used:
See Section 14.4.2.1.
If ITP Interposer Is Used:
See Section 14.4.2.2.
If ITP Not Supported:
See Section 14.4.2.3.
TRST#
If ITP700FLEX Is Used:
See Section 14.4.2.1.
If ITP Interposer Is Used:
See Section 14.4.2.2.
If ITP Not Supported:
See Section 14.4.2.3.
Intel Pentium M/Intel Celeron M Processor – Power Signals
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1
Intel Pentium M/Intel Celeron M Processor – Resistor Recommendations
Pin Name
System
Series Termination
Resistor (
Pull up/Pull
down
VCC[71:0]
Tie to
VCC[Vcc_Core]
VCCA[3:0]
Tie to Vcc1_8
Notes
9
72 VCC pins
See layout example in Section 5.3.
Also see Section 14.4.4 for decoupling.
VCCP[26:0]
Tie to VCCP
27 VCCP pins
VCCSENSE
Pull down to GND
54.9
± 1%
(Default: No Stuff)
Stuffing option for 54.9
± 1% pull
down to GND should be provided for
testing purposes. For normal operation,
resistor should be No Stuff.
Also, a test point for a differential probe
ground should be placed between the
two termination resistors of VCCSENSE
and VSSSENSE.
Intel Pentium M/Intel Celeron M Processor – GND Signals
VSS[191:0]
Tie to GND
VSSSENSE
Pull down to GND
192 VSS pins
54.9
± 1%
(Default: No Stuff)
Stuffing option for 54.9
± 1% pull
down to GND should be provided for
testing purposes. For normal operation,
resistor should be No Stuff.
Also, a test point for a differential probe
ground should be placed between the
two termination resistors of VCCSENSE
and VSSSENSE.
NOTE:
Default tolerance for resistors is ± 5% unless otherwise specified.
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Figure 148. Processor GTLREF Voltage Divider Network
+VCCP
R1
1K
1%
< 1/2"
Zo = 55Ω trace
GTLREF
R2
2K
1%
GTLREF
(pin AD26)
RSVD
(pin E26)
RSVD
(pin AC1)
Intel
Pentium M
processor
RSVD
(pin G1)
Figure 149. Routing Illustration for INIT#
Intel
FWH
3.3V
V_IO_FWH
3.3V
Intel
ICH4-M
Intel
Pentium M
processor
R2
R1
L4
Q2
L1
L2
L3
Rs
282
3904
Q1
3904
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Figure 150. Voltage Translation Circuit
3.3V
3.3V
1.3K ohm
+/- 5%
From Driver
330 ohm
+/- 5%
330 ohm
+/- 5%
R1
R2
To Receiver
Q2
3904
Q1
3904
Rs
Figure 151. Routing Illustration for PROCHOT#
3.3V
Intel
Pentium M
Processor
System Receiver
V_IO_RCVR
3.3V
VCCP
L1
L2
Intel® 855PM Chipset Platform Design Guide
L4
Q2
L3
Rs
R2
R1
Rtt
3904
Q1
3904
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14.4.2.
In Target Probe (ITP)
14.4.2.1.
ITP700FLEX Connector 1, 2
ITP700FLEX Debug Port Connector – Resistor Recommendations
Pin Name
Series Termination
Resistor (
System
Pull up/Pull down
BPM[5:0]#
Notes
9
ITP700FLEX supported Validation
Systems:
Point-to-point connection to CPU via a
Zo = 55 trace.
ITP700FLEX
BPM[3:0]#
to
CPU
BPM[3:0]#
BPM[4]#
PRDY#
BPM[5]#
PREQ#
ITP700FLEX supported Production
Systems:
Leave the signals as NC (No Connect).
DBA#
Pull up to target
VCC
150
- 240
DBA# is an optional signal that may be
implemented when the ITP700FLEX is
used.
ITP700FLEX supported Validation
Systems:
Pull up resistor should be placed within
1 ns of the ITP700FLEX.
ITP700FLEX supported Production
Systems:
Leave this signal as NC (No Connect).
See Section 4.3.1.1 and 4.3.1.4 for
details.
DBR#
Pull up to target
VCC or See Notes
150
- 240
ITP700FLEX supported Validation
Systems:
The signal needs to be routed to system
reset logic (e.g. connect to
SYS_RESET# of ICH4-M with pull up to
VccSUS3_3). Pull up resistor must be
placed within 1 ns of the ITP700FLEX.
ITP700FLEX supported Production
Systems:
Pull up may be required depending on
impact to system reset logic that it is
connected to.
See Section 4.3.1.1 and 4.3.1.4 for
details.
RESET#
TCK
See RESET# in Section 14.4.1
Pull down to GND
27.4
± 1%
(IF ITP700FLEX
IS USED)
27
(IF ITP700FLEX
IS NOT USED)
284
ITP700FLEX supported Validation
Systems:
Parallel termination resistor placed
within ±200 ps of ITP700FLEX.
ITP700FLEX supported Production
Systems:
Intel® 855PM Chipset Platform Design Guide
Platform Design Checklist
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ITP700FLEX Debug Port Connector – Resistor Recommendations
Pin Name
Series Termination
Resistor (
System
Pull up/Pull down
Notes
9
Parallel termination resistor placed
within 2.0” of CPU socket.
See Section 4.3.1.1 and 4.3.1.4 for
details..
FBO
See Notes
ITP700FLEX supported Validation
Systems:
Point-to-point connection to CPU TCK
pin. TCK should fork out at the CPU to
both TCK and FBO.
ITP700FLEX supported Production
Systems:
Leave the signal as NC (No Connect).
See Section 4.3.1.1 and 4.3.1.4 for
details.
TDI
Pull up to VCCP
150
ITP700FLEX supported Validation
Systems:
(IF ITP700FLEX
IS USED)
Parallel termination resistor placed
within ±300 ps of CPU TDI pin.
150
ITP700FLEX supported Production
Systems:
(IF ITP700FLEX
IS NOT USED)
Parallel termination resistor placed
within 2.0” of CPU pin.
See Section 4.3.1.1 and 4.3.1.4 for
details.
TDO
Pull up to VCCP
54.9
± 1%
(IF ITP700FLEX
IS USED)
22.6
± 1%
(IF ITP700FLEX IS
USED)
ITP700FLEX supported Validation
Systems:
Signal needs to be pulled up to VCCP.
Series dampening resistor placed within
1.0” of ITP700FLEX TDO pin.
ITP700FLEX supported Production
Systems:
Leave the signal as NC (No Connect).
See Section 4.3.1.1 and 4.3.1.4 for
details.
TMS
Pull up to VCCP
39.2
± 1%
(IF ITP700FLEX
IS USED)
39
(IF ITP700FLEX
IS NOT USED)
ITP700FLEX supported Validation
Systems:
Parallel termination resistor placed
within ±200 ps of the ITP700FLEX TMS
pin.
ITP700FLEX supported Production
Systems:
Parallel termination resistor placed
within 2.0” of CPU pin.
See Section 4.3.1.1 and 4.3.1.4 for
details.
TRST#
Pull down to GND
510
- 680
(IF ITP700FLEX
IS USED)
Intel® 855PM Chipset Platform Design Guide
ITP700FLEX supported Validation
Systems:
Parallel termination resistor can be
285
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ITP700FLEX Debug Port Connector – Resistor Recommendations
Pin Name
Series Termination
Resistor (
System
Pull up/Pull down
Notes
9
placed anywhere between CPU and
ITP700FLEX. Avoid any trace stub from
signal line to parallel termination
resistor.
680
(IF ITP700FLEX
IS NOT USED)
ITP700FLEX supported Production
Systems:
Parallel termination resistor placed
within 2.0” of CPU pin.
See Section 4.3.1.1 and 4.3.1.4 for
details.
VTAP,
VTT[1:0]
Tie to VCCP
The signals are tied together to VCCP.
One 0.1 µF decoupling cap is required
See section 4.3.1.1 for more details.
NOTES:
1. See Section 14.4.2.2 if ITP Interposer is implemented.
2. See Section 14.4.2.3 if NO processor ITP debug port solution is implemented.
3. Default tolerance for resistors is +/-5% unless otherwise specified.
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14.4.2.2.
ITP Interposer 1, 2
ITP Interposer
Pin Name
Series Termination
Resistor (
System
Pull up/Pull down
BPM[5:0]#
DBA#
Notes
9
Leave the signals as NC (No Connect).
Pull up to target
VCC
150
- 240
DBA# is an optional signal that may be
implemented when an ITP Interposer is
used.
ITP Interposer supported Validation
Systems:
Pull up resistor should be placed within
1 ns of CPU socket.
ITP Interposer supported Production
Systems:
Leave this signal as NC (No Connect).
See section 4.3.2 and 4.3.2.2 for more
details.
DBR#
Pull up to
V3ALWAYS
150
- 240
ITP Interposer supported Validation
Systems
This signal needs to be routed to
system reset logic (e.g. SYS_RESET#
of ICH4-M). Pull up resistor must be
placed within 1ns of CPU socket.
ITP Interposer supported Production
Systems:
Pull up may be required depending on
impact to system reset logic that it is
connected to.
See section 4.3.2 and 4.3.2.2 for more
details.
RESET#
See RESET# in Section 14.4.1.
TCK
Pull down to GND
27
Pull down needs to be placed within
2.0” of CPU socket.
TDI
Pull up to VCCP
150
Pull up needs to be placed within 2.0” of
CPU socket.
TMS
Pull up to VCCP
39
Pull up needs to be placed within 2.0” of
CPU socket.
TRST#
Pull down to GND
680
Pull down needs to be placed within
2.0” of CPU socket.
TDO
Leave this signal as NC (No Connect)
NOTES:
1. See Section 14.4.2.1 if ITP700FLEX connector is implemented.
2. See Section 14.4.2.3 if NO processor ITP debug port solution is implemented.
3. Default tolerance for resistors is +/-5% unless otherwise specified.
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14.4.2.3.
Required Strapping when ITP Debug Port Disable 1, 2
ITP Interposer
Pin Name
Series Termination
Resistor (
System
Pull up/Pull down
Notes
TCK
Pull down to GND
27
Pull down needs to be placed within
2.0” of CPU socket.
TDI
Pull up to VCCP
150
Pull up needs to be placed within 2.0” of
CPU socket.
TDO
9
Leave the signal as NC (No Connect).
TMS
Pull up to VCCP
39
Pull up needs to be placed within 2.0” of
CPU socket.
TRST#
Pull down to GND
680
Pull down needs to be placed within
2.0” of CPU socket.
NOTES:
1. See Section 14.4.2.1 if ITP700FLEX connector is implemented.
2. See Section 14.4.2.3 if NO processor ITP debug port solution is implemented.
3. Default tolerance for resistors is +/-5% unless otherwise specified.
14.4.3.
Thermal Sensor
Platform recommendations and design guidelines provided by your diode thermal sensor vendor should
be adhered to ensure proper operation of your thermal sensor.
14.4.4.
Decoupling Recommendations
Decoupling Recommendations
Signal
VCCA[3:0]
Configuration
1
F
Qty
Notes
10 µF
4
VCCA[3:0] should be tied to Vcc1_8.
10 nF
4
One 1206 form factor 10 µF and one 0603
form factor 10 nF capacitor pair should be
used for each VCCA pin.
9
See Section 5.3.1 for details on guidelines
for placement and routing of the VCCA
decoupling capacitors
VCC[Vcc_core]
220 µF
4
Polymer Covered Aluminium (SP, AO
Cap)
10 µF
35
0805 MLCC, >=X6R
See Section 5.9.3 for details on guidelines
for placement and routing of the
VCC[Vcc_core] decoupling capacitors.
VCCP
150 µF
1
0.1 µF
10
Polymer Covered Tantalum (POSCAP,
Neocap, KO Cap)
0603 MLCC, >= X7R.
Place all capacitors next to CPU.
Also see Section 14.6.4 for VCCP
decoupling requirement at the MCH.
See Section 5.9.4 for details on Intel
processor and MCH VCCP voltage plane
288
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Decoupling Recommendations
Signal
Configuration
F
1
Qty
Notes
9
and decoupling.
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14.5.
CK-408 Clock Checklist
14.5.1.
Resistor Recommendations
CK-408 Clock – Resistor Recommendations
Pin Name
System
Series Resistor
(
Pull up/Pull down
3V66[5:0]
33
Notes
9
Use three clock signals for MCH, ICH4-M,
and AGP controller.
See Section 10.2.2 for MCH and ICH4-M
CLK66 routing requirements.
CPU[0], CPU[0]#
CPU[1], CPU[1]#
CPU[2], CPU[2]#
Pull down to GND
49.9
± 1%
33
It is required to connect one CPU clock
pair to processor and another pair to MCH.
See Section 12.2.1 for further discussion.
If ITP700FLEX Is Used:
rd
Route 3 CPU clock pair to ITP700FLEX
(Routing to CPU socket NOT necessary).
See Section 4.3.1.3 for routing
requirements.
If ITP Interposer Is Used:
rd
Route 3 CPU clock pair to the ITP_CLK
signals of the CPU socket (Routing to
ITP700FLEX NOT necessary).
CPU_STOP#
Point to point connection to the ICH4-M’s
STP_CPU# signal.
DOT
33
If the signal is used, one 33 series
resistor is required for each receiver.
If NOT used, this signal can be left as NC
(No Connect).
IREF
Pull down to GND
MULT[0]
Pull up to Vcc3_3
PCI[6:0]
475
± 1%
10 k
33
If the signal is used, one 33 series
resistor is required for each receiver.
If NOT used, this signal can be left as NC
(No Connect).
See Section 10.2.5 for routing
requirements.
PCI_STOP#
PCIF[2:0]
Point to point connection to the ICH4-M’s
STP_PCI# signal.
33
Use one free running PCI clock signal for
the ICH4-M.
If NOT used, this signal can be left as NC
(No Connect).
See 10.2.4 for routing requirements.
PWRDWN#
If S1M Is Supported:
This signal should be driven by the logical
AND of the ICH4-M’s SLP_S1# and
SLP_S3# signals. See Figure 152.
If S1M Is NOT Supported but S3 is
supported:
290
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CK-408 Clock – Resistor Recommendations
Pin Name
System
Series Resistor
(
Pull up/Pull down
Notes
9
This signal should be driven by the ICH4M’s SLP_S3# signal.
REF
33
If the signal is used, one 33 series
resistor is required for each receiver.
If NOT used, this signal can be left as NC
(No Connect).
See Section 10.2.7 for routing
requirements.
SEL[2:1]
Pull down to GND
1K
SEL[0]
Pull up to Vcc3_3
1K
USB
33
If the signal is used, one 33
series
resistor is required for each receiver.
If NOT used, this signal can be left as NC
(No Connect).
XTAL_IN
None
Connect to XTAL_OUT through a 14.318
MHz clock. Place crystal within 500 mils of
CK-408.
See Notes
XTAL_OUT
None
Connect to XTAL_IN through a 14.318
MHz clock. Place crystal within 500 mils of
CK-408.
See Notes
CK-408 Clock – Power Signals
VDD[7:0],
VDDA
Tie to Vcc3_3
See Notes
Also see Section 14.5.2 for decoupling
requirement.
CK-408 Clock – GND Signals
VSS[5:0]
Tie to GND
VSSA
Tie to GND
VSSIREF
Tie to GND
NOTE: Default tolerance for resistors is +/-5% unless otherwise specified.
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Figure 152. Clock Power Down Implementation
Vcc3_3Sus /
V3ALWAYS
PM_SLP_S1#
PM_SLP_S3#
14.5.2.
CLK_PWRDWN#
CK-408 Decoupling Recommendation
Platform recommendations and decoupling guidelines provided by your CK-408 vendor should be
adhered to ensure proper operation of your clock chip.
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14.6.
Intel 855PM MCH Checklist
14.6.1.
System Memory
14.6.1.1.
MCH System Memory Interface
Intel 855PM MCH – System Memory Interface
Pin Name
System
Series
Resistor (
Pull up/Pull down
RCVENIN#
Notes
9
Point to point connection to RCVENOUT#.
See Section 6.1.5 for routing requirements.
RCVENOUT#
Point to point connection to RCVENIN#.
See Section 6.1.5 for routing requirements.
SBS[1:0]
Pull up to
Vcc1_25[DDR_Vtt]
56
10
Two routing topologies available for these
signals. See Section 6.1.3 for routing
requirements.
SCAS#
Pull up to
Vcc1_25[DDR_Vtt]
56
10
Two topologies available for routing this signal.
See Section 6.1.3 for routing requirements.
SCKE[3:0]
Pull up to
Vcc1_25[DDR_Vtt]
56
See Section 6.1.2 for routing requirements.
SCS#[3:0]
Pull up to
Vcc1_25[DDR_Vtt]
56
See Section 6.1.2 for routing requirements.
SDQ[63:0]
Pull up to
Vcc1_25[DDR_Vtt]
56
SDQ[71:64]
Pull up to
Vcc1_25[DDR_Vtt]
56
See Notes
10
See Section 6.1.1 for routing requirements.
10
See Section 6.1.1 for routing requirements.
See Notes
See Notes
SDQS[7:0]
SDQS[8]
If ECC is NOT Supported:
These signals can be left as NC (No Connect).
Pull up to
Vcc1_25[DDR_Vtt]
56
Pull up to
Vcc1_25[DDR_Vtt]
56
10
See Section 6.1.1 for routing requirements.
Note that MCH package lengths must be
accounted for when length matching DDR
strobes and clocks. See package length
information in Section 6.2.
See Notes
10
See Notes
See Notes
Note that MCH package lengths must be
accounted for when length matching DDR
strobes and clocks. See package length
information in Section 6.2.
If ECC is NOT Supported:
This signal can be left as NC (No Connect).
SMA[12:0]
Pull up to
Vcc1_25[DDR_Vtt]
SMVREF[1:0]
Voltage Divider
56
10
Two routing topologies available for these
signals. See Section 6.1.3 for routing
requirements.
10 k
1%
(top)
In S3, SMVREF [1:0] can be turned OFF.
1%
10 k
(bottom)
Reference voltage = (Vcc2_5 ± 5%) / 2 ± 2%.
Note that a buffer is used to provide the
necessary current and reference voltage to
SMVREF[1:0]. A simple voltage divider may not
be able to provide the necessary tolerance for
these pins.
Intel® 855PM Chipset Platform Design Guide
SMVREF[1:0] should be tied together.
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Intel 855PM MCH – System Memory Interface
Pin Name
System
Series
Resistor (
Pull up/Pull down
Notes
9
See Figure 153 and Section 11.5.3.1 for details.
SRAS#
Pull up to
Vcc1_25[DDR_Vtt]
56
10
Two routing topologies available for these
signals. See Section 6.1.3 for routing
requirements.
SWE#
Pull up to
Vcc1_25[DDR_Vtt]
56
10
Two routing topologies available for these
signals. See Section 6.1.3 for routing
requirements.
Intel 855PM MCH – System Memory Clock Signals
SCK[5:0],
SCK[5:0]#
These differential clock signals can be routed to
any SO-DIMM provided that the BIOS
understands the routing implementation.
Trace width option #2 (inner layer trace width=7
mils) is the recommended implementation for
improved DDR timing margin.
See Section 6.1.4 for routing requirements.
Note that MCH package lengths must be
accounted for when length matching DDR
strobes and clocks. See package length
information in Section 6.2.
If ECC is NOT Supported:
rd
The 3 differential clock pair routed to each SODIMM for ECC should be left as NC (No
Connect). Intel design guidelines assume nonECC memory utilizes only 2 SCK clock pairs.
Intel 855PM MCH – System Memory Power Signals
VCCSM[37:0]
Tie to VccSus2_5
See Section 14.6.4 for VccSus2_5 decoupling
requirement.
NOTE: Default tolerance for resistors is +/-5% unless otherwise specified.
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Figure 153. Reference Voltage Level for SMVREF[1:0]
Vcc2_5/VccSus2_5
10k+/-1%
1%
10k+/-1%
%
Intel® 855PM Chipset Platform Design Guide
+
-
Intel
855PM
MCH
SMVREF
SMVREF0
SMVREF1
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14.6.1.2.
DDR SO-DIMM Interface
DDR SO-DIMM Interface
Pin Name
System
Pull up/Pull down
Series
Resistor
Notes
9
DDR SO-DIMM – ECC Related Signals
CB[7:0]
See Notes
These signals are ECC related.
If ECC Is Supported:
These signals need to be routed to MCH. See
SDQ[71:64] in Section 14.6.1.1.
If ECC Is NOT Supported:
These signals can be left as NC (No Connect).
CKx, CKx#
CKy, CKy#
See Notes
These signals are ECC related. CKx/CKx# and
rd
CKy/CKy# are the 3 differential clock signal
used to support ECC memory devices on a
SO-DIMM module.
If ECC Is Supported::
These signals need to be routed to MCH. See
SCK[5:0], SCK[5:0]# in Section 14.6.1.1.
If ECC Is NOT Supported:
These signals should be left as NC (No
Connect).
DQS[8]
See Notes
This signal is ECC related.
If ECC Is Supported:
This signal needs to be routed to MCH. See
DQS[8] in Section 14.6.1.1.
If ECC Is NOT Supported:
These signals can be left as NC (No Connect).
DDR SO-DIMM – Reference Voltage Signals
VREF[2:1]
See Notes
In S3, VREF[2:1] are powered ON in Intel
CRB.
Reference voltage = (VccSus2_5 ± 8%) / 2 ±
4%. Note that a buffer is used to provide the
necessary current and reference voltage to
VREF. A simple voltage divider may not be
able to provide the necessary tolerance for
these pins.
See Section 11.5.6 for details.
DDR SO-DIMM Interface-- Power Signals
VDD[33:1]
Tie to VccSus2_5
VDDSPD
Tie to Vcc3_3
Power must be supplied during S3.
DDR SO-DIMM Interface—GND Signals
DM[8:0]
Tie to GND
VSS[31:1]
Tie to GND
DDR SO-DIMM Interface—No Connect Signals
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DU[4:1]
See Notes
This signal can be left as NC (No Connect).
GND[1:0]
See Notes
This signal can be left as NC (No Connect).
RESET(DU)
See Notes
This signal can be left as NC (No Connect).
VDDID
See Notes
This signal can be left as NC (No Connect).
DDR SO-DIMM Interface—Misc Signal
SA[2:0]
Tie to GND /
Connect to VCC3_3
See Notes
SPD EEPROM Address Detection:
For 1st SO-DIMM address ‘A0’:
SA[2:0] should be tied to GND
For 2nd SO-DIMM address ‘A2’:
SA[0] – Tie to VCC3_3
SA[2:1] – Tie to GND
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14.6.2.
Miscellaneous Signals
MCH – Miscellaneous Signals
Pin Name
System
F
Notes
9
Pull up/Pull down
External Thermal Sensor Based Throttling Signal
ETS#
See Notes
See Notes
If ETS# Is NOT Used: (Default is Disabled)
No external pull up is required.
If ETS# Is Used:
This signal needs to be pulled up to a 2.5 V
source through a 8.2 k to 10 k
See Section 6.8 for details.
Hub Interface Signals
HSWNG[1:0]
301 ± 1%
(top)
Signal voltage level = 1/3 * VCCP.
150 ± 1%
(bottom)
R1a = R1b = 301
± 1%
R2a = R2b = 150
± 1%
C1a = C1b = 0.1 uF
See See Figure 154 and Section 4.1.8.2 for
details.
VCCHL[4:0]
Tie to Vcc1_8
Also see Section 14.6.4 for Vcc1_8 decoupling
requirement.
Other Signals
TESTIN
This signal can be left as NC (No Connect).
Power Signals
VCC[9:0]
Tie to
Vcc1_2[Vcc_mch]
VTT[19:0]
Tie to VCCP
See Section 14.6.4 for VCC_MCH decoupling
requirements.
Ground Signals
VSS[141:0]
298
Tie to GND
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Figure 154. Intel 855PM MCH HSWNG[1:0] Reference Voltage Generation Circuit
+VCCP
R1a
301Ω
1%
+VCCP
C1a
0.1uF
C1b
0.1 uF
HSWNG[0]
HSWNG[1]
Intel
855PM
MCH
HSWNG[0]
R2a
150Ω
1%
301
1%
HSWNG[1]
150
1%
Figure 155. Intel 855PM MCH HVREF[4:0] Generation Circuit
+VCCP
R1
Ω
1%
MCH_GTLREF
R2
Ω
1%
AB16
AB12
C1
200 pF
C2
200 pF
C3
1 uF
AA9
P8
M7
Intel® 855PM Chipset Platform Design Guide
HVREF
HVREF
HVREF
HVREF
Intel
855PM
MCH
HVREF
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14.6.3.
Resistive Compensation
MCH – Resistive Compensation
Pin Name
System
Notes
9
Pull up/Pull down
GRCOMP
Pull down to GND
36.5
± 1%
GRCOMP resistor value = 2/3 * AGP routing channel
impedance.
Intel CRB uses 40.2
GRCOMP.
± 1% pull down resistor for
HLRCOMP
Pull up to Vcc1_8
36.5
± 1%
HLRCOMP resistor value = 2/3 * board impedance.
HRCOMP[1:0]
Pull down to GND
27.4
± 1%
Each signal should be pulled down to ground through a
27.4 ± 1% resistor with a Zo = 27.4 trace.
Max trace length from pin to resistor should be < 0.5”
and ~18 mils wide. Recommend routing 25 mils away
from any switching signal.
See Section 4.1.8.2 for details.
SMRCOMP
Pull up to
Vcc1_25[DDR_Vtt]
30.1
± 1%
In S3, Vcc1_25[DDR_Vtt] (DDR channel termination
voltage) can be turned OFF.
One 0.1 µF decoupling cap is required for this signal.
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14.6.4.
Decoupling Recommendations (MCH)
MCH– Decoupling Recommendations
1
Pin Name
Configuration
F
Qty
Notes
SMRCOMP
Tie to Vcc1_25[DDR_Vtt]
0.1 µF
1
Decoupling capacitor must be connected to
the power-side of the RCOMP resistor.
Vcc1_8
Tie to Vcc1_8
0.1 µF
2
Two 0.1 µF capacitors are recommended
for Vcc1_8 decoupling. All values are
preliminary.
9
See Section 8.5 for details
VccSus2_5
Tie to VccSus2_5
0.1 µF
15
Place within 150 mils of MCH package.
See Section 11.5.1.1
VCC-MCH
VCCGA, VCCHA
VCCP
14.6.5.
Tie to VCC_MCH
Tie to Vcc1_8
Tie to VCCP
150 µF
2
2.2 µF
1
220 nF
1
47 nF
1
22 nF
1
15 nF
1
10 nF
1
10 µF
1
10 nF
1
10 µF
1
0.1 µF
8
See Section 5.9.5for details.
VCCGA and VCCHA can both share a 10
µF and 10nF decoupling capacitor.
Polymer covered tantalum. Place next to
the MCH.
0603 MLCC, >= X7R. Place next to the
MCH.
Memory Decoupling Recommendation
Memory Decoupling Recommendations
Pin Name
Configuration
F
Qty
Vcc1_25[DDR_Vtt]
See Notes
0.1 µF
See Notes
1
Notes
9
In S3, Vcc1_25[DDR_Vtt] (DDR channel
termination voltage) can be turned OFF.
Place one 0.1 µF close to every 2 pull up
resistors terminated to Vcc1_25[DDR_Vtt].
See Section 11.7.4 for details.
VccSus2_5
0.1 µF
9
Place capacitors between the SO-DIMMs .
See Section 11.5.1.2 for details.
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14.6.6.
MCH Reference Voltage
MCH – Reference Voltage
Pin Name
System
Notes
9
Pull up/Pull down
AGPREF
Voltage divider
HI_REF
Voltage divider
1 k ± 1%
(top & bottom)
100
- 150
± 1%
(top & bottom)
See Notes
HIVREF(ICH4-M signal), HI_VSWING (ICH4-M signal),
and HI_REF(MCH signal) may share a common hub
interface reference voltage divider if the divider is
located within 3” from both the MCH and ICH4-M.
See Figure 157 and Section 8.4 for more details.
For each of the 3 signals, a locally generated hub
interface reference voltage divider must be used if the
common reference voltage divider is located more than
3” away from the component.
See Figure 158 and Section 8.4 for more details.
HVREF[4:0]
49.9 ± 1%
(top)
Place R1 close to HVREF4 (ballout AB16) and R2
close to HVREF1 (ballout P8).
100 ± 1%
(bottom)
See Figure 155.
R1a = 49.9
± 1%
R2a = 100
± 1%
C1 = 200 pF C2 = 200 pF C3 = 1 µF
See Section 4.1.7 for routing requirements.
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14.7.
AGP Interface
14.7.1.
Resistor Recommendations
Intel 855PM MCH AGP Interface – Resistor Recommendations
Pin Name
System
Pull up/Pull
down
AD_STB[1:0]
Series
Damping
See Notes
Notes
9
Point to point connection to AGP controller.
MCH has an internal pull up. External pull up is
NOT required.
AD_STB[1:0]#
See Notes
Point to point connection to AGP controller.
MCH has an internal pull down. External pull
down is NOT required.
DEVSEL#
FRAME#
GNT#
IRDY#
REQ#
STOP#
TRDY#
PIPE#
RBF#
WBF#
See Notes
SB_STB
See Notes
Point to point connection to AGP controller.
MCH has an internal pull up. External pull up is
NOT required.
Point to point connection to AGP controller.
MCH has an internal pull up. External pullup is
NOT required.
SB_STB#
See Notes
Connect directly to AGP controller.
MCH has an internal pull down. External pull
down is NOT required.
Intel(R) Intel 855PM MCH AGP Interface – Power Signals
VCCAGP[15:0]
Tie to Vcc1_5
Also see Section 11.7.5 for decoupling
requirement.
NOTE: Default tolerance for resistors is +/-5% unless otherwise specified.
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14.7.1.1.
AGP Connector
AGP Connector Resistor Recommendations
Pin Name
System
Series
Damping
Pull up/Pull down
SERR#, PERR#
Pull up to Vcc1_5
8.2 k
9
PERR# and SERR# are not supported in
the MCH. An external pull up to a 1.5 V
source is required for AGP controllers
that implement these signals.
INTA#, INTB#
14.7.1.2.
Notes
Route to the ICH4-M PIRQ signals.
AGP Decoupling Recommendations
1
Intel 855PM MCH Interface – High Frequency Decoupling Recommendations
Pin Name
Configuration
F
Qty
Notes
Vcc1_5
Pull down to GND
0.01 µF
6
Place a minimum of six 0.01 µF within 70
mils of the outer row of balls on the MCH.
9
Place one extra 0.01 µF cap for every 10
vias that transition the AGP signal from
one reference signal plane to another.
Intel CRB uses 7x 0.1 µF, 1x 22 µF, and
1x 100 µF.
14.7.1.3.
AGP VREF Reference Voltage Dividers
MCH AGP Interface – Reference Voltage Dividers
Pin Name
System
Notes
9
Pull up/Pull down
AGPREF
Voltage divider
1k
1k
top)
bottom)
Source generated VREFs are recommended. See
Section 7.3.8 for more details.
See Figure 156 for impelementation on Intel CRB.
304
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Figure 156. AGPREF Implementation (On Intel CRB)
Vcc1_5
Intel 855PM
1KΩ
AGP
MCH
AGPREF
Vrefcg
1KΩ
0.1uF
Place near MCH
Intel® 855PM Chipset Platform Design Guide
0.1uF
Place near AGP
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14.8.
ICH4-M Checklist
All inputs to the ICH4-M must not be left floating. Many GPIO signals are fixed inputs that must be
pulled up to different sources.
Note:
14.8.1.
ICH4-M Resistor Recommendations
ICH4-M – Resistor Recommendations
Pin Name
System
Series
Damping
Pull up/Pull down
Notes
9
PCI Resistor Recommendations
DEVSEL#
Pull up to Vcc3_3
8.2 k
FRAME#
Pull up to Vcc3_3
8.2 k
GPIO0/REQA#
Pull up to Vcc3_3
8.2 k
Each signal requires a pull up.
GPIO1/REQB#/
REQ5#
GPIO16 / GNTA#
See Notes
GNT[A] has an added strap function of “top
block swap”. This signal is sampled on the
rising edge of PWROK. By default, this signal is
HIGH or strap function is DISABLE.
Strap function can be enabled by pulling down
this signal to GND through a 1 k resistor.
IRDY#
Pull up to Vcc3_3
8.2 k
LOCK#
Pull up to Vcc3_3
8.2 k
PERR#
Pull up to Vcc3_3
8.2 k
SERR#
Pull up to Vcc3_3
8.2 k
STOP#
Pull up to Vcc3_3
8.2 k
TRDY#
Pull up to Vcc3_3
8.2 k
REQ[4:0]#
Pull up to Vcc3_3
8.2 k
Each signal requires a pull up.
Interrupt Interface Resistor Recommendations
APICCLK
Pull down to GND
(If NOT Used)
APICD[1:0]
Pull down to GND
(If NOT Used)
Recommended to disable APICCLK and
APICD[1:0].
10 k
Recommended to disable APICCLK and
APICD[1:0]:
If XOR Chain Testing Is NOT Used: Pull down
the signals through a shared 10-k resistor.
If XOR Chain Testing Is Used: Each signal
requires a separate 10-k pull down resistor.
IRQ[15:14]
306
Pull up to Vcc3_3
8.2 k 10 k
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ICH4-M – Resistor Recommendations
Pin Name
System
Series
Damping
Pull up/Pull down
PIRQ#[A:D]
PIRQE#/GPIO2
PIRQF#/GPIO3
PIRQG#/GPIO4
PIRQH#/GPIO5
Pull up to Vcc3_3
SERIRQ
Pull up to Vcc3_3
8.2 k
See Notes
Notes
9
External pull up is required for
INT_PIRQ#[A:D].
External pull-up is required when muxed signal
(INT_PIRQ[E:H]#/ GPIO[2:5]) is implemented
as PIRQ.
8.2 k
NOTE: Default tolerance for resistors is +/-5% unless otherwise specified.
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14.8.2.
GPIO
Checklist Items
GPIO Balls
Recommendations
Reason/Impact
GPIO[7] & [5:0]:
These balls are in the Main Power Well. Pull-ups must use
the VCC3_3 plane.
Ensure ALL unconnected signals are
OUTPUTS ONLY!
Unused core well inputs must be pulled up to VCC3_3.
GPIO[1:0] can be used as REQ[B:A]#.
GPIO[1] can be used as PCI REQ[5]#.
GPIO[5:2] can be used as PIRQ[H:E]#.
These signals are 5-V tolerant
These pins are inputs
GPIO[8] & [13:11]:
These balls are in the Resume Power Well. Pull-ups go to
VCCSus3_3 plane.
Main power well GPIOs are 5-V tolerant,
except for GPIO[43:32]. Resume power
well GPIOs are not 5-V tolerant
Unused resume well inputs must be pulled up to VCCSus3_3.
These are the only GPIs that can be used as ACPI
compliant wake events.
These signals are not 5-V tolerant.
GPIO[8] can be used as SMC_EXTSMI#
GPIO[11] can be used as SMBALERT#.
GPIO[13] can be used as SMC_WAKE_SCI#
These pins are inputs
GPIO[23:16]:
Fixed as output only. Can be left NC.
In Main Power Well (VCC3_3).
GPIO[17:16] can be used as GNT[B:A]#.
GPIO[17] can be used as PCI GNT[5]#.
STP_PCI#/GPIO[18] – used in mobile as STP_PCI# only.
SLP_S1#/GPIO[19] – used in mobile as SLP_S1# only.
STP_CPU#/GPIO[20] – used in mobile as STP_CPU# only.
C3_STAT#/GPIO[21] – used in mobile as C3_STAT# only.
CPUPERF#/GPIO[22] – open drain signal. Used in mobile
as CPUPERF# only.
SSMUXSEL/GPIO[23] – used in mobile as SSMUXSEL only.
GPIO[28,27,25,24]:
I/O balls. Default as outputs. Can be left NC.
These pins are in the Resume Power Well
CLKRUN#/GPIO[24] (Note: use pull up to VCC3_3 if signal is
required to be pulled up)
GPIO[28, 27, 25] From resume power well (VCCSus3_3).
(Note: use pull up to VCC3_3 if this signal is pulled up)
These signals are NOT 5-V tolerant.
GPIO[25] can be used as AUDIO_PWRDN
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GPIO[43:32]:
I/O balls. From main power well (VCC3_3).
Default as outputs when enabled as GPIOs
These signals are NOT 5-V tolerant
GPIO[32] can be used as AGP_SUSPEND#
GPIO[33] can be used as KSC_VPPEN#
GPIO[34] can be used as SER_EN
GPIO[35] can be used as FWH_WP#
GPIO[36] can be used as FWH_TBL#
GPIO[40] can be used as IDE_PATADET
GPIO[41] can be used as IDE_SATADET
14.8.3.
AGP Busy/Stop Design Requirements
AGP Busy/Stop design requirements
Signal
System
Notes
9
Pull up/Pull down
AGPBUSY#
Pull up to Vcc3_3
10 k
This ICH4-M signal requires a pull up to the switched
3.3-V rail (the 3.3V power rail which will be powered
OFF during S3).
This ICH4-M signal must be connected to the
AGP_BUSY# output of the external AGP Graphics
Controller.
C3_STAT#
No pull up/pull down
required.
See notes
SUS_STAT#
No pull up/pull down
required.
See notes
When an external AGP device is enabled, this signal
must be connected from ICH4-M to the external AGP
Graphics Controller for STP_AGP# signal
implementation.
When an external AGP device is enabled, this signal
must be connected from ICH4-M to the external AGP
Graphics Controller if the AGP device is designed to
use this signal.
Assertion of this ICH4-M signal indicates that the
system will be entering one of the S1-S5 low-power
states, and that the platform clocks (including the AGP
clock) will soon stop toggling.
This signal can be monitored by devices with memory
that need to switch from normal refresh to suspend
refresh mode. It can also be used as an indication that
the peripherals should isolate their outputs that may be
going to powered-off planes.
NOTE: Please also consult Intel for the latest AGP Busy and Stop signal implementation.
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14.8.4.
System Management Bus (SMBus) Interface
ICH4-M System Management Interface – Resistor Recommendations
Pin Name
System
Notes
9
Pull up/Pull down
INTRUDER#
Pull up to VccRTC
10 k
SMBALERT#/
GPIO[11]
Pull up to V3ALWAYS
10 k
SMBCLK
SMBDATA
Pull up to V3ALWAYS
See Notes
RTC well input requires pull up to reduce leakage from
coin cell battery in G3.
Requires external pull up resistors. Pull up value is
determined by bus section characteristics. Additional
circuitry may be required to connect high and low
powered sections.
Resistor change for faster rise time and to ensure
timings are within specification. Value of pull up resistor
is also determined by line load.
Intel CRB uses 10K pull up resistor. Please see Intel
CRB schematics page 18.
The SMBus and SMLink signals must be tied together
externally in S0 for SMBus 2.0 compliance:
SMBCLK connects to SMLink[0]
SMBDATA connects to SMLink[1]
SMLINK[1:0]
Pull up to V3ALWAYS
See Notes
Requires external pull up resistors. Pull up value is
determined by bus section characteristics. Additional
circuitry may be required to connect high and low
powered sections.
Resistor change for faster rise time and to ensure
timings are within specification. Value of pull up resistor
is also determined by line load.
Intel CRB uses 4.7 k pull up resistor. Please see Intel
schematics page 18.
The SMLink and SMBus signals must be tied together
externally in S0 for SMBus 2.0 compliance:
SMLink[0] connects to SMBCLK
SMLink[1] connects to SMBDATA
310
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14.8.5.
AC ’97 Interface
ICH4-M AC ’97 Interface – Resistor Recommendations
Pin Name
System
Pull up/Pull down
AC_BIT_CLK
Series
Termination
Resistor
33
- 47
Notes
9
The internal pull down resistor is controlled by
the AC’97 Global Control Register, ACLINK
Shut Off bit:
1 = enabled
0 = disabled
When no AC'97 devices are connected to the
link, BIOS must set the ACLINK Shut Off bit for
the internal keeper resistors to be ENABLED.
At that point, pull ups/pull downs are NOT
needed on ANY of the link signals.
See Section 9.3 for routing requirements
AC_SDIN[2:0]
33
- 47
A series termination resistor (R1) is required for
the PRIMARY CODEC.
A series termination resistor is required for the
SECONDARY (R2=R1) and TERTIARY
(R3=R1) CODEC if the resistor is not found on
CODEC.
See Section 9.3 for routing requirements.
AC_SDOUT
33
- 47
A series termination resistor is required for the
PRIMARY CODEC.
One series termination resistor (R2=R1) is
required for the SECONDARY/ TERTIARY
CODEC connector card if the resistor is not
found on the connector card.
See Section 9.3 for routing requirements.
AC_SYNC
33
- 47
A series termination resistor is required for the
PRIMARY CODEC.
One series termination resistor (R2=R1) is
required for the SECONDARY/ TERTIARY
CODEC connector card if the resistor is not
found on the connector card.
See Section 9.3 for routing requirements.
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14.8.6.
ICH4-M Power Management Interface
ICH4-M Power Management Interface – Resistor Recommendations
Pin Name
System
Series
Damping
Pull up/ Pull
down
DPRSLPVR
Notes
9
External pull down not required. Signal has
integrated pull down in ICH4-M.
External pull up not required. Signals driven by
ICH4-M.
SLP_S1#
SLP_S3#
SLP_S4#
SLP_S5#
BATLOW#
See Notes
10 k
CLKRUN#
Pull up to
Vcc3_3
10 k
PWRBTN#
Pull up is not required if it is used. However,
signal must not float if it is NOT being used
(Signal should be pull up to V3ALWAYS
through a 10 k pull up resistor).
When asserted, this ICH4-M input signal will
indicate a system request to go into a sleep
event or cause a wake event (if the system is
already in a Sleep state).
This signal is recommended to connect to a
power button or any other equivalent driver.
This signal has integrated pull up External pull
up/down not required.
PWROK
Pull down to
GND
100 k
See Notes
RTC well input requires pull down to reduce
leakage from coin cell battery in G3. Input must
not float in G3.
This signal should be connected to power
monitoring logic and should go high no sooner
than 10 ms after both Vcc3_3 and Vcc1_8 have
reached their nominal voltages.
Intel CRB uses a 100 k pull down to reduce
leakage from coin cell battery in G3.
RI#
Pull up to
V3ALWAYS
10 k
If this signal is enabled as a wake event, it is
important to keep this signal powered during a
power loss event. If this signal goes low
(active), when power returns the RI_STS bit will
be set and the system will interpret that as a
wake event.
RSMRST#
Pull down to
GND
100 k
RSMRST# is a RTC well input and requires pull
down to reduce leakage from coin cell battery in
G3. Input must not float in G3.
This signal should be connected to power
monitoring logic and should go high no sooner
than 5 ms after both VccSus3_3 and
VccSus1_5 have reached their nominal
voltages.
Intel CRB uses a 100 k pull-down to reduce
leakage from coin cell battery in G3.
THRM#
Pull up to
Vcc3_3
(If NOT USED)
312
8.2 k
If THRM# Is Used:
(If NOT
Used)
THRM# is a 3.3 V tolerant signal. Voltage
translation may be required if other thermal
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ICH4-M Power Management Interface – Resistor Recommendations
Pin Name
System
Series
Damping
Pull up/ Pull
down
Notes
9
sensors are used.
If THRM# Is NOT Used:
If this signal is not connected to a driver, then it
is required to be terminated with a 8.2 k pull
up to Vcc3_3.
SYS_RESET#
Pull up to
VccSus3_3
100 k (if
signal is not
used)
Implementation of this signal is optional. When
this signal is asserted, system will be put into
reset.
If SYS_RESET# Is Used:
A weak pull up is required to prevent the signal
from floating.
If SYS_RESET# Is NOT Used:
Pull up to VccSus3_3 through a 100 k
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14.8.7.
FWH/LPC Interface
ICH4-M FWH/LPC Interface – Resistor Recommendations
Pin Name
System
Series
Damping
Pull up/Pull down
FWH[3:0]/LAD[3:0]
14.8.8.
Notes
9
Extra pull ups not required. Connect directly
to FWH/LPC.
See Notes
USB Interface
ICH4-M USB Interface – Resistor Recommendations
Pin Name
System
Series
Damping
Pull up/Pull down
OC[5:0]#
Pul lup to V3ALWAYS
10 k
Notes
9
These signals are inputs into the ICH4-M and
must not be left floating. Pull up is required.
If an OC pin is not connected to a current
monitor or equivalent device for a given USB
port, an alternative mechanism should be
provided to handle a potential over current
condition.
USBRBIAS
USBRBIAS#
Pull down to GND
22.6 ±
1%
Tie signals together and pull down through a
common 22.6 ± 1% resistor.
The RBIAS resistor should be placed within 500
mils of the ICH4-M and avoid routing next to
clock pins.
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14.8.9.
Hub Interface
14.8.9.1.
Hub Interface Resistor Recommendations
ICH4-M Hub Interface – Resistor Recommendations
Pin Name
System
Notes
9
Pull up/Pull down
HICOMP
Pull down to GND
36.5
See Notes
± 1%
HICOMP resistor value = 2/3 * board impedance.
Place resistor within 0.5” of ICH4-M pad using a thick
trace.
Intel CRB uses 36.5
± 1% resistor.
NOTE: Default tolerance for resistors is +/-5% unless otherwise specified.
14.8.9.2.
Reference Voltage Dividers
1
ICH4-M Hub Interface – Reference Voltage Dividers
Pin Name
System
Notes
9
Pull up/Pull down
HIVREF
See Notes
HIVREF, HI_VSWING and HI_REF(MCH signal) can
share a common hub interface reference divider. Also
see Figure 157.
For each of the 3 signals, a locally generated hub
interface reference divider must be used if the common
reference divider is located at more than 3” away.
Please see Figure 158.
See page 8 and 15 in the Intel CRB schematics.
HI_VSWING
See Notes
HIVREF, HI_VSWING and HI_REF(MCH signal) can
share a common hub interface reference divider. Also
see Figure 157.
For each of the 3 signals, a locally generated hub
interface reference divider must be used if the common
reference divider is located at more than 3” away.
Please see Figure 158.
See page 8 and 15 in the Intel CRB schematics.
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Figure 157. Hub Interface with Signal Reference Voltage Divider Circuit
VCC HI=1.8V
Intel
R1
Intel 855PM
MCH
ICH4-M
HIREF
HI_VSWING
HIREF
C1
R2
C2
C1 C1
NOTES:
R1=R2=100 to 150 
C1=0.01 uF
C2=0.1 uF
Figure 158. Hub Interface with Locally Generated Reference Voltage Divider Circuit
VCC HI=1.8V
R1
HI_VSWING
HIREF
Intel
ICH4-M
R2
C1
NOTES::
R1=R2=100 to 150
C1=0.01 uF
C2=0.1uF
316
C1

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14.8.10.
RTC Circuitry
ICH4-M RTC Circuitry Topology Recommendations
Pin Name
System
Notes
9
Pull up/Pull down
RTCRST#
Vcc_RTC
CLK_RTCX1,
CLK_RTCX2
See notes
180 k
Pull up to VccRTC through a 180 k resistor. Also see
Section 8.16 for decoupling requirements. RTC_RST#
should have a 18 – 25 ms delay. Any RC circuit which
will result in the 18-25 ms delay is acceptable.
Connect a 32.768 kHZ crystal oscillator across these
pins with a 10 m resistor and use a decoupling cap at
each signal.
Please consult Section 9.8.2 for calculating a specific
capacitance value for C1 and C2.
See Figure 159
Please note that peak-to-peak swing on RTCX1 cannot
exceed 1.0 V
CLK_VBIAS
See notes
Connect to CLK_RTCX1 through a 10-m resistor.
Connect to Vbatt through a 1k ohms in series with a
0.047-µF capacitor.
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Figure 159 External Circuitry for the RTC
VCCRTC
3.3V Sus
1uF
RTCX2
1kΩ
R1
10M Ω
32.768 kHz
Xtal
Vbatt
RTCX1
C3
0.047uF
C1
C2
R2
10M Ω
VBIAS
Notes
Reference Designators Arbitrarily Assigned
3.3V Sus is Active Whenever System Plugged In
Vbatt is Voltage Provided By Battery
318
VBIAS, VCCRTC, RTCX1, and RTCX2 are ICH4-M pins
VBIAS is used to bias the ICH4 Internal Oscillator
VCCRTC powers the RTC well of the ICH4-M
RTCX1 is the Input to the Internal Oscillator
RTCX2 is the feedback for the external crystal
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14.8.11.
LAN Interface
ICH4-M LAN Interface Recommendations
Pin Name
System
Notes
9
Pull up/Pull down
LAN_CLK
See Notes
Connect to LAN_CLK on the platform LAN Connect
Device.
See Section 9.9.2 for routing requirements.
If LAN interface is not used, leave the signal
unconnected (NC)
LAN_RST#
See Notes
Timing Requirement: Signal should be connected to
power monitoring logic, and should go high no sooner
than 5 ms after both VccLAN3_3 and VccLAN1_5 have
reached their nominal voltages.
NOTE: If ICH4-M LAN controller is NOT used, pull
LAN_RST# down through a 10K resistor.
LAN_RXD[2:0]
See Notes
Connect to LAN_RXD on the platform LAN Connect
Device.
See Section 9.9.2 for routing requirements.
If LAN interface is not used, leave the signal
unconnected (NC)
LAN_TXD[2:0]
See Notes
Connect to LAN_TXD on Platform LAN Connect
Device.
See Section 9.9.2for routing requirements.
If LAN interface is not used, leave the signal
unconnected (NC)
LAN_RSTYSNC
See Notes
Connect to LAN_RSTSYNC on Platform LAN Connect
Devce.
See Section 9.9.2 for routing requirements.
If LAN interface is not used, leave the signal
unconnected (NC).
VCCLAN1.5[1:0]
VCCLAN3.3[1:0]
See Notes
If ICH4-M LAN connect interface is used:
Connect VCCLAN1.5[1:0] to the customer designated
1.5VLAN power rail
Connect VCCLAN3.3[1:0] to the customer designated
3.3VLAN power rail
If ICH4-M LAN connect interface is not used:
Connect VCCLAN1.5[1:0] to Vcc1_5
Connect VCCLAN3.3[1:0] to Vcc3_3
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14.8.12.
Primary IDE Interface
ICH4-M IDE Interface – Resistor Recommendations
Pin Name
System
Series
Damping
Pull up/Pull down
PDD[15:0]
Notes
9
No extra series termination resistors or other
pull ups/pull downs are required. These signals
have integrated series resistors.
None
PDD7/SDD7 does not require a 10 KΩ pull
down resistor.
NOTE: Simulation data indicates that the
integrated series termination resistors are a
nominal 33 Ω but can range from 31 Ω to 43 Ω.
Refer to ATA ATAPI-4 specification.
PDA[2:0],
PDCS1#,
PDCS3#,
PDDACK#,
PDIOW#, PDIOR#
None
No extra series termination resistors. Pads for
series resistors can be implemented should the
system designer have signal integrity concerns.
These signals have integrated series resistors.
NOTE: Simulation data indicates that the
integrated series termination resistors are a
nominal 33 but can range from 31 to 43 .
PDDREQ
No extra series termination resistors.
None
No pull-down resistors needed.
These signals have integrated series resistors
in the ICH4-M.
These signals have integrated pull down
resistors in the ICH4-M.
PIORDY
PCI_RST#
Mobile IDE Swap
Bay Support
320
Pull up to Vcc3_3
4.7 k
This signal has integrated series resistor in the
ICH4-M
22
- 47
The signal must be buffered to form IDE_RST#
for improved signal integrity.
See Section 9.1.4 for implementating the ICH4M’s IDE interface tri-state feature. This feature
can be used for systems designed to support an
IDE “hot” swap drive bay.
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14.8.13.
IDE Interface (Secondary IDE Connector)
ICH4-M IDE Interface – Resistor Recommendations
Pin Name
System
Series
Damping
Pull up/Pull down
SDD[15:0]
Notes
9
No extra series termination resistors or other
pull ups/pull downs are required. These signals
have integrated series resistors.
None
PDD7/SDD7 does not require a 10 KΩ pull
down resistor.
NOTE: Simulation data indicates that the
integrated series termination resistors are a
nominal 33 Ω but can range from 31 Ω to 43 Ω.
Refer to ATA ATAPI-4 specification.
SDA[2:0],
SDCS1#,
SDCS3#,
SDDACK#,
SDIOW#, SDIOR#
None
No extra series termination resistors. Pads for
series resistors can be implemented should the
system designer have signal integrity concerns.
These signals have integrated series resistors.
NOTE: Simulation data indicates that the
integrated series termination resistors are a
nominal 33 but can range from 31 to 43 .
SDDREQ
No extra series termination resistors.
None
No pull down resistors needed.
This signal has integrated series resistors in
the ICH4-M.
This signal has integrated pull down resistors in
the ICH4-M.
SIORDY
Pull up to Vcc3_3
4.7 k
PCI_RST#
Mobile IDE Swap
Bay Support
Intel® 855PM Chipset Platform Design Guide
This signal has integrated series resistor in the
ICH4-M
22
- 47
The signal must be buffered to form IDE_RST#
for improved signal integrity.
See Section 9.1.4 contains recommendations
for implementating the ICH4-M’s IDE interface
tri-state feature. This feature can be used for
systems designed to support an IDE “hot” swap
drive bay.
321
Platform Design Checklist
R
14.8.14.
Miscellaneous Signals
ICH4-M Miscellaneous Signals
Pin Name
System
Pull up/Pull down
SPKR
See notes
Series
Damping
Notes
9
SPKR is a strapping option for the TCO Timer
Reboot function and is sampled on the rising
edge of PWROK. An integrated weak pull down
is enabled only at boot/reset. Status of strap is
readable via the NO_REBOOT bit (D31:F0,
Offset D4h, bit 1)
1 = disabled
0 = enabled (normal operation)
To disable, a jumper can be populated to pull
SPKR high. Value of pull up must be such that
the voltage divider output caused by the pull up,
effective impedance of speaker and codec
circuit, and internal pull down will be read as
logic high (0.5 * Vcc3_3 to Vcc3_3 + 0.5)
322
Intel® 855PM Chipset Platform Design Guide
Platform Design Checklist
R
14.8.15.
ICH4-M Power Signals & Decoupling Recommendations
1,2
ICH4-M – Power Signals & Decoupling Recommendations
Pin Name
System
Notes
9
Pull up/Pull down
VCC1.5[15:0]
Tie to Vcc1_5
Two 0.1 µF capacitors (place near balls: K23 and C23)
are required for decoupling.
VCC3.3[15:0]
Tie to Vcc3_3
Six 0.1 µF capacitors (place near ball : A1, A4, H1, T1,
AC10, and AC18) are required for decoupling.
VCCSUS1.5[7:0]
Tie to V1_5ALWAYS
Two 0.1 µF capacitors (place near balls: A16 and AC1)
are required for decoupling.
VCCSUS3.3[9:0]
Tie to V3ALWAYS
Two 0.1 µF capacitors (place near ball: A22 and AC5)
are required for decoupling.
VCCLAN1.5[1:0]
Tie to VccSus1_5
Two 0.1 µF capacitors (place near ball: F6 and F7) are
required for decoupling.
VCCLAN3.3[1:0]
Tie to VccSus3_3
Two 0.1 µF capacitors (place near ball: E9 and F9) are
required for decoupling.
VCC5REF[2:1]
Tie to Vcc5
VCC5REFSUS1
See Notes
1k
One 0.1 µF capacitor (place near ball: E7) is required
for decoupling.
One 0.1 µF capacitor (place near ball: A16) is required
for decoupling.
If Wake on USB from S3 and self-powered USB
devices are supported:
Tie to V5ALWAYS
If Wake on USB from S3 and self-powered USB
devices are NOT supported:
Tie to a combination of V3ALWAYS and Vcc5 or
VccSus5. See Section 11.4.1.3 for more details.
VCC_CPU_IO[2:0]
Tie to VCCP
One 0.1 µF capacitor (place near ball: AA23) is
required for decoupling.
VCCPLL
Tie to Vcc1_5
One 0.1 µF and one 0.01 uF capacitors (place near ball
C22) are required for decoupling.
VCCRTC
Tie to Vcc_RTC
One 0.1 µF capacitor (place near ball: AB5) is required
for decoupling.
VCCHI[3:0]
Tie to Vcc1_8
Two 0.1 µF capacitors (place near balls: T23 and N23)
are required for decoupling.
NOTES:
1. All decoupling guidelines are recommendations based on our reference board design. Customers will need to take their layout,
and PCB board design into consideration when deciding on their overall decoupling solution
2. Capacitors should be place less than 100 mils from the package
Intel® 855PM Chipset Platform Design Guide
323
Platform Design Checklist
R
14.9.
USB Checklist
14.9.1.
Resistor Recommendations
USB – Resistor Recommendations
Pin Name
System
Pull up/Pull
down
Series
Damping
USBPWR_CONN[E:A]
Notes
9
Each signal requires a LC Pi filter that consists
of one 0.1 µF, one 100 µF and one ferrite bead
in Intel CRB. See Figure 160
Both caps on Pin 2 of ferrite bead. Optimal
decoupling achieve with 100 µF cap on
connector side of ferrite bead.
NOTE: Default tolerance for resistors is +/-5% unless otherwise specified.
Figure 160. USBPWR_CONN[E:A] Design Recommendation
USBPWR_
CONN[D:A]
Ferrite Bead (50 Ohms)
1
2
0.1uF 100uF
Vcc
324
Intel® 855PM Chipset Platform Design Guide
Platform Design Checklist
R
14.9.2.
Decoupling Recommendations
USB – Decoupling Recommendations
Signal
Configuration
F
Qty
V5_USB[3:1] (signal)
Pull down to GND
0.1 µF
1
1
Notes
9
In Intel CRB, each signal requires a
decoupling cap.
NOTE: All decoupling guidelines are recommendations based on our reference board design. Customers will need to take their layout,
and PCB board design into consideration when deciding on their overall decoupling solution.
14.10.
FWH Checklist
14.10.1.
Resistor Recommendations
FWH – Resistor Recommendations
Pin Name
System
Series
Damping
Pull up/Pull down
FGPI[4:0]
See Notes
Notes
9
Can be connected directly to GND
In Intel CRB, each signal requires a 100 ohms
pull down resistor.
IC
See Notes
In Intel CRB, the signal requires a 10 kohms
pull down resistor.
RST#
100
In Intel CRB, the signal requires a 100 ohms
series damping resistor.
FWH – Power SIgnals
VCC[2:1]
VCCA
VPP
Tie to Vcc3_3
GND[2:1],
GNDA
Tie to GND
Also see Section 10.2 for decoupling
requirement.
See Notes
FWH – GND SIgnals
FWH – Test Point Signals
ID[3:0]
See Notes
Signals are recommended to be connected to
test points.
RSVD[5:1]
See Notes
Signals are recommended to be connected to
test points.
FWH – Not Connected Signals
NC[8:1]
None
The signals should be left as NC (“Not
Connected”)
NOTE: Default tolerance for resistors is +/-5% unless otherwise specified.
14.10.2.
Decoupling Recommendations
FWH – Decoupling Recommendations
Pin Name
Configuration
Intel® 855PM Chipset Platform Design Guide
F
Qty
1
Notes
9
325
Platform Design Checklist
R
FWH – Decoupling Recommendations
Pin Name
Configuration
F
Qty
VCC[2:1]
VCCA
VPP
Pull down to GND
0.1 µF
2
4.7 µF
1
1
Notes
9
In Intel CRB, two 0.1 µF s and one 4.7 µF
capacitors are used for decoupling. The
decoupling recommendation is shared
among all 5 signals.
Please see Intel CRB schematics.
NOTE: All decoupling guidelines are recommendations based on our reference board design. Customers will need to take their layout,
and PCB board design into consideration when deciding on their overall decoupling solution.
14.11.
LAN / HomePNA Checklist
14.11.1.
LAN Interface (82562ET / 82562EM)
14.11.1.1.
Resistor Recommendations
LAN – Resistor Recommendations
Pin Name
System
Series
Damping
Pull up/Pull down
ISOL_EX,
ISOL_TCK,
ISOL_TI
Pull up to
VccSus3_3LAN
Notes
10 k
9
All three signals are pulled up to
VccSus3_3LAN through a common 10 kohms
pull up resistor.
See Figure 161
RBIAS10
Pull down to GND
549
± 1%
RBIAS100
Pull down to GND
619
±1%
RDP, RDN
See Notes
121
± 1%
Connect RDP to RDN through a 121ohms
resistor
TDP, TDN
See Notes
100
± 1%
Connect TDP to TDN through a 100 +/ 1%
resistor.
TESTEN
Pull down to GND
X1
X2
See Notes
100
This signal is pulled down to ground through a
100 in Intel CRB.
Connect a 25 MHz crystal across these two
pins.
LAN – Power Signals
VCC[2:1],
VCCP[2:1],
VCCA[2:1],
VCCT[4:1],
VCCR[2:1]
Tie to VccSus3_3
Also see Section 11.1.2 for decoupling
requirement.
LAN – GND Signals
VSS[5:1],
VSSP[2:1],
VSSA[2:1],
VSSR[2:1]
Tie to GND
NOTE: Default tolerance for resistors is +/-5% unless otherwise specified.
326
Intel® 855PM Chipset Platform Design Guide
Platform Design Checklist
R
Figure 161. LAN_RST# Design Recommendation (On Intel CRB)
VccS us3_3LAN
82562E M
10k
IS O L_TC K
IS O L_TI
IS O L_E X
LA N_R S T
14.11.1.2. Decoupling Recommendations
1
LAN – Decoupling Recommendations
Signal Name
Configuration
F
Qty
VccLan3_3
Pull down to GND
0.1 µF
4.7 µF
4
2
VccLan_L3_3
Pull down to GND
0.1 µF
4.7 µF
1
1
LAN_X1, LAN_X2
Pull down to GND
22 pF
1
Notes
9
Each pin requires a decoupling cap
NOTE: All decoupling guidelines are recommendations based on our reference board design. Customers will need to take their layout,
and PCB board design into consideration when deciding on their overall decoupling solution.
Intel® 855PM Chipset Platform Design Guide
327
Platform Design Checklist
R
This page intentionally left blank.
328
Intel® 855PM Chipset Platform Design Guide
Intel Customer Reference Board Schematics
R
15.
Intel Customer Reference Board
Schematics
See the following page for customer reference board schematics.
Intel® 855PM Chipset Platform Design Guide
329
A
B
C
D
E
4
4
IMVP IV VR
ITP CK-408
PG 37,38,39
PG 5
3
AGP PM
Header
1.5V
AGP
SLOT
PG 14
PG 3,4
PG 10
PSB
266
DDR
SDRAM
AGP 1.5V, 66MHz
Intel 855PM
MCH
PG 9
PG 10
SODIMM1
PG 35
PCPU
Thermal
Sensor
PG 5
Clocking
SODIMM0
Fan
Header
Processor
478 uFCPGA
3
593 uFCBGA
PG 6,7,8
DDR VR
Hub Interface
66MHz
PG 40
USB 2.0
421 BGA
LAN CONNECT
PG 15,16,17
PG 21
PG 22
PG 25
82562EM
PG 27
MDC
Header
PG 19
5V PCI SLOT 1
PG 19
5V PCI SLOT 2
PG 20
5V PCI SLOT 3
2
RJ45
PG 34
FWH
PG 24
LPC, 33MHz
8 Mbit
LPC
SLOT
USB3
USB1
USB0
Docking
Connector
PG 26
PG 25
Q-Switch
33MHz PCI
ICH4-M
AC97
PG 25
2
ATA 100
USB4
USB2
PG 26
USB5
(Docking)
PG 26
IDE1
IDE0
PG 23,24
PG 28
SIO
PG 41
PG 31
PG 33
PG 29
PS/2
PG 33
LPC PM
Headers
PG 34
Serial
Parallel
FIR
PG 32
PG 32
PG 32
Scan
KB
FDD
PG 33
PG 32
Size
A
Date:
B
PS/2
Hitachi H8S
2149
PG 30
Title
A
SMC/KBC
PG 30
Suspend
Timer
Turner
System
DC/DC
Connector
1
PORT80
PC87393
C
1
BLOCK DIAGRAM
Document Number
Project:
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
of
1
E
4
7
A
B
C
D
E
SCHEMATIC ANNOTATIONS AND BOARD INFORMATION
4
3
4
2
Voltage Rails
I C / SMB Addresses
+VDC
+VCC_CORE
+VCCP
+V1.2S_MCH
+V1.25
+V1.5S
+V1.5ALWAYS
+V1.5
+V1.8S
+V2.5
+V3.3ALWAYS
+V3.3
+V3.3S
+V5ALWAYS
+V5
+V5S
+V12S
-V12S
Device
Clock Generator
SO-DIMM0
SO-DIMM1
Thermal Diode
Smart Battery
Smart Battery Charger
Smart Selector
Primary DC system power supply (10 to 21V)
Core voltage for Processor
1.05V rail for Processor I/O
1.2V For 855PM Core(off in S3-S5)
DDR Termination voltage(off in S4-S5)
1.5V switched power rail (off in S3-S5)
1.5V always on power rail
1.5V power rail (off in S4-S5)
1.8V switched power rail (off in S3-S5)
2.5V power rail for DDR
3.3V always on power rail
3.3V power rail (off in S4-S5)
3.3V switched power rail (off in S3-S5)
5.0V always on power rail
5.0V power rail (off in S4-S5)
5.0V switched power rail (off in S3-S5)
12.0V switched power rail (off in S3-S5)
-12.0V switched power rail for PCI (off in S3-S5)
IDSEL #
AD25
AD26
AD27
AD28
(AD17 internal)
(AD24 internal)
REQ/GNT #
1
1
2
2
3
3
4
4
Hex
D2
A0
A2
9C
16
12
14
Bus
SMB_ICH
SMB_ICH
SMB_ICH
SMB_THRM
SMB_SB
SMB_SB
SMB_SB
#
= Active Low signal
LED
Page
Ref
SMC/KBC SCROLL LOCK.........................29.................................DS3
SMC/KBC NUMLOCK.............................29.................................DS1
SMC/KBC CAPS LOCK...........................29.................................DS4
Secondary IDE...............................24.................................DS7
Primary IDE.................................24.................................DS8
PWR/SUS LED.................................24.................................DS6
ON_BOARD_VR_PWRGD...........................38.................................DS2
SW
Page
Ref
VIRTUAL BATTERY.............................29.................................SW1
LID.........................................29.................................SW2
POWER.......................................40.................................SW3
RESET.......................................40.................................SW4
Default Jumper Settings
J1
1-X
KBC 60/64 DECODE DISABLE
J6
1-X
INIT CLK DISABLE
J12
1-2
SMC/KBC DISABLE
J21
1-X
SMC/KBC Programming
J52
1-2
SIO Disable
J94
1-X
CMOS CLEAR
PCI Devices
Device
Slot 1
Slot 2
Slot 3
Docking
AGP
LAN
Address
1101 001x
1010 000x
1010 001x
1001 110x
0001 011x
0001 001x
0001 010x
Net Name Suffix
Interrupts
A, B, C, D
B, C, D, A
C, D, A, B
B, C, D, A
A, B
PC/PCI
A
A
A
B
3
Page
29
30
29
29
31
16
Wake Events
RI# (Ring Indicate) from serial port
PME# (Power Management Event) from
PCI/mini-PCI slots, AGP slot, LPC slot
LCI I/O from 82562EM
LID switch attached to SMC
USB
AC97 wake on ring
SmLink for AOL II
Hot Key from the scan matrix keyboard
2
DDR Termination:
Command/Address
MA, BS#, RAS#, CAS#, WE#
1 Series and 1 Parallel
DATA
1 Series and 1 Parallel
DQS, DATA, CB
1 Parallel
Control/Enable CKE, CS#
POWER STATES
PCB Footprints
SIGNAL
STATE
SLP_S1#
SLP_S4#
SLP_S5# +V*ALWAYS
+V*
+V*S
HIGH
HIGH
HIGH
ON
ON
ON
ON
LOW
HIGH
HIGH
HIGH
ON
ON
ON
LOW
S3 (Suspend to RAM)
LOW
LOW
HIGH
HIGH
ON
ON
OFF
OFF
S4 (Suspend To Disk)
LOW
LOW
LOW
HIGH
ON
OFF
OFF
OFF
S1M (Power On Suspend)
S5 / Soft OFF
LOW
A
LOW
LOW
LOW
ON
B
OFF
OFF
As seen from top
SOT-23
1
Clocks
HIGH
Full ON
1
SLP_S3#
3
3
Title
Size
A
Date:
C
5
1
SOT23-5
2
2
OFF
2
1
4
Notes and Annotations
Document Number
Project:
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
of
2
E
4 7
A
B
C
D
E
+VCCP 4,5,7,15,16,17,37,39,42
U26A
H_REQ#0
H_REQ#1
H_REQ#2
H_REQ#3
H_REQ#4
H_A#[31:3]
7
H_ADSTB#1
15 H_A20M#
15 H_FERR#
15 H_IGNNE#
H_DEFER# 7
H_DRDY# 7
H_DBSY# 7
N4
A4
B5
LOCK#
J2
CONTROL
BR0#
IERR#
INIT#
REQ0#
REQ1#
REQ2#
REQ3#
REQ4#
A17#
A18#
A19#
A20#
A21#
A22#
A23#
A24#
A25#
A26#
A27#
A28#
A29#
A30#
A31#
ADSTB#1
C2
D3
A3
A20M#
FERR#
IGNNE#
C6
D1
D4
B4
STPCLK#
LINT0
LINT1
SMI#
B11
H1
K1
L2
M3
+VCCP 4,5,7,15,16,17,37,39,42
R396
150
R386
56
R401
0
H_TDI
H_BR0# 7
H_INIT# 15,34
H_LOCK# 7
H_CPURST# 5,7,42
H_RS#[2:0] 7
H_RS#0
H_RS#1
H_RS#2
H_TRDY# 7
7
H_D#[63:0]
C8
B8
A9
C9
A10
B10
A13
C12
A12
C11
B13
A7
H_BPM0_ITP# 5
H_BPM1_ITP# 5
H_BPM2_ITP# 5
H_BPM3_ITP# 5
H_BPM4_PRDY# 5
H_BPM5_PREQ# 5
H_TCK 5
PROCHOT#
THERMDA
THERMDC
B17
B18
A18
H_PROCHOT_S# 5
H_THERMDA 5
H_THERMDC 5
7
7
7
H_DSTBN#0
H_DSTBP#0
H_DINV#0
THERMTRIP#
C17
PM_THRMTRIP# 16
7
H_D#[63:0]
ITP_CLK1
ITP_CLK0
BCLK1
BCLK0
A15
A16
B14
B15
CLK_ITP_CPU# 14
CLK_ITP_CPU 14
CLK_CPU_BCLK# 14
CLK_CPU_BCLK 14
TP_GTLREF3 AC1
TP_GTLREF2
G1
TP_GTLREF1 E26
GTL_REF0
AD26
GTLREF3
GTLREF2
GTLREF1
GTLREF0
H_D#21
H_D#22
H_D#23
H_D#24
H_D#25
H_D#26
H_D#27
H_D#28
H_D#29
H_D#30
H_D#31
+VCCP
2
+VCCP
7
7
7
R108
1K_1%
R3001
1K_1%
H_DSTBN#1
H_DSTBP#1
H_DINV#1
0.5" max length
+VCCP
GTL2_REF0
J3001
2 GTL_REF0_D
D16#
D17#
D18#
D19#
D20#
D21#
D22#
D23#
D24#
D25#
D26#
D27#
D28#
D29#
D30#
D31#
DSTBN1#
DSTBP1#
DINV1#
H_D#18
H_D#19
H_D#20
4,5,7,15,16,17,37,39,42
1
H23
G25
L23
M26
H24
F25
G24
J23
M23
J25
L26
N24
M25
H26
N25
K25
K24
L24
J26
H_D#16
H_D#17
R135
49.9_1%
4,5,7,15,16,17,37,39,42
D0#
D1#
D2#
D3#
D4#
D5#
D6#
D7#
D8#
D9#
D10#
D11#
D12#
D13#
D14#
D15#
DSTBN0#
DSTBP0#
DINV0#
H_D#3
H_D#4
H_D#5
H_D#6
H_D#7
H_D#8
H_D#9
H_D#10
H_D#11
H_D#12
H_D#13
H_D#14
H_D#15
H_TDO 5
H_TMS 5
H_TRST# 5
ITP_DBRESET# 5,41
R134
49.9_1%
A19
A25
A22
B21
A24
B26
A21
B20
C20
B24
D24
E24
C26
B23
E23
C25
C23
C22
D25
H_D#2
Pentium M-Processor
1
A1
B2
TP_NC_1
TP_NC_2
TP_NC_3
NO_STUFF_CON3_HDR
R3002
2K_1%
H_D#32
D32# Y26
H_D#33
D33# AA24 H_D#34
D34# T25
H_D#35
U23
D35#
H_D#36
D36# V23
H_D#37
R24
D37#
H_D#38
D38# R26
H_D#39
R23
D39#
H_D#40
D40# AA23 H_D#41
U26
D41#
H_D#42
D42# V24
H_D#43
D43# U25
H_D#44
D44# V26
H_D#45
Y23
D45#
H_D#46
D46# AA26
H_D#47
D47# Y25
DSTBN2# W25
DSTBP2# W24
DINV2# T24
7
3
H_DSTBN#2 7
H_DSTBP#2 7
H_DINV#2 7
H_D#[63:0]
H_D#48
D48# AB25
H_D#49
D49# AC23 H_D#50
D50# AB24
H_D#51
D51# AC20
H_D#52
D52# AC22 H_D#53
AC25
D53#
H_D#54
D54# AD23 H_D#55
D55# AE22 H_D#56
AF23
D56#
H_D#57
D57# AD24 H_D#58
D58# AF20 H_D#59
D59# AE21
H_D#60
D60# AD21
H_D#61
D61# AF25
H_D#62
AF22
D62#
H_D#63
D63# AF26
AE24
DSTBN3#
DSTBP3# AE25
DINV3# AD20
7
2
H_DSTBN#3 7
H_DSTBP#3 7
H_DINV#3 7
COMP0
COMP1
COMP2
COMP3
P25
P26
AB2
AB1
Comp0 +VCCP 4,5,7,15,16,17,37,39,42
Comp1
Comp2
Comp3
R385
332_1%
DPSLP#
DPWR#
PWRGOOD
SLP#
B7
C19
E4
A6
H_DPSLP#
TEST1
TEST2
C5
F23
TEST1
TEST2
MISC
2
3
J100
NO_STUFF_CON3_HDR
3
H_D#[63:0]
U26B
H_D#0
H_D#1
BPM#0
BPM#1
BPM#2
BPM#3
PRDY#
PREQ#
TCK
TDI
TDO
TMS
TRST#
DBR#
H_TDI
Note:
R401,R400,R177 not needed
for Customer Platforms
R400
No_Stuff_825
Place testpoint on
H_IERR# with a GND
0.1" away
H_HIT# 7
H_HITM# 7
4,5,7,15,16,17,37,39,42
4
TDI_FLEX 5
H_IERR#
K3
K4
HIT#
HITM#
R177
NO_STUFF_150
DATA GRP 3
15,34 H_STPCLK#
15,34 H_INTR
15,34 H_NMI
15,34 H_SMI#
L4
H2
M2
DATA GRP 2
3
AF4
AC4
AC7
AC3
AD3
AE4
AD2
AB4
AC6
AD5
AE2
AD6
AF3
AE1
AF1
AE5
DEFER#
DRDY#
DBSY#
RESET#
RS0#
RS1#
RS2#
TRDY#
ADDR GROUP 1
H_A#17
H_A#18
H_A#19
H_A#20
H_A#21
H_A#22
H_A#23
H_A#24
H_A#25
H_A#26
H_A#27
H_A#28
H_A#29
H_A#30
H_A#31
R2
P3
T2
P1
T1
H_ADS# 7
H_BNR# 7
H_BPRI# 7
DATA GRP 0
7
H_ADSTB#0
H_REQ#[4:0]
ADS#
BNR#
BPRI#
N2
L1
J3
DATA GRP 1
7
7
+VCCP 4,5,7,15,16,17,37,39,42
A3#
A4#
A5#
A6#
A7#
A8#
A9#
A10#
A11#
A12#
A13#
A14#
A15#
A16#
ADSTB#0
ITP SIGNALS
4
P4
U4
V3
R3
V2
W1
T4
W2
Y4
Y1
U1
AA3
Y3
AA2
U3
ADDR GROUP 0
H_A#3
H_A#4
H_A#5
H_A#6
H_A#7
H_A#8
H_A#9
H_A#10
H_A#11
H_A#12
H_A#13
H_A#14
H_A#15
H_A#16
THERM
H_A#[31:3]
H CLK
7
R109
2K_1%
42 TP_NC_4
36
TP_NC_5
Comp0
Comp1
Comp2
Comp3
NC0
NC1
C14
C3
AF7
C16
E1
RSVD1
RSVD2
RSVD3
RSVD4
RSVD5
H_DPSLP# 6,15,34
H_DPWR# 6
H_PWRGD 15,34
H_CPUSLP# 15,34
Pentium M-Processor
R387
NO_STUFF_1K
R130
NO_STUFF_1K
1
1
+VCCP 4,5,7,15,16,17,37,39,42
R378
54.9_1%
R377
27.4_1%
R381
54.9_1%
R379
27.4_1%
R532
NO_STUFF_150
B
Processor 1 of 2
Size Project:
Custom
855PM Platform
Monday, February 24, 2003
Date:
H_DPSLP#
A
Title
C
D
Document Number
Sheet
Rev
3
of
E
4 7
A
B
C
D
38,39 +VCC_CORE
E
38,39 +VCC_CORE
U26D
A2
A5
A8
A11
A14
A17
A20
A23
A26
AA1
AA4
AA6
AA8
AA10
AA12
AA14
AA16
AA18
AA20
AA22
AA25
AB3
AB5
AB7
AB9
AB11
AB13
AB15
AB17
AB19
AB21
AB23
AB26
AC2
AC5
AC8
AC10
AC12
AC14
AC16
AC18
AC21
AC24
AD1
AD4
AD7
AD9
AD11
AD13
AD15
AD17
AD19
AD22
AD25
AE3
AE6
AE8
AE10
AE12
AE14
AE16
AE18
AE20
AE23
AE26
AF2
AF5
AF9
AF11
AF13
AF15
AF17
AF19
AF21
AF24
B3
B6
B9
B12
B16
B19
B22
B25
C1
C4
C7
C10
C13
C15
C18
C21
C24
D2
D5
D7
D9
D11
4
3
2
VSS0
VSS1
VSS2
VSS3
VSS4
VSS5
VSS6
VSS7
VSS8
VSS9
VSS10
VSS11
VSS12
VSS13
VSS14
VSS15
VSS16
VSS17
VSS18
VSS19
VSS20
VSS21
VSS22
VSS23
VSS24
VSS25
VSS26
VSS27
VSS28
VSS29
VSS30
VSS31
VSS32
VSS33
VSS34
VSS35
VSS36
VSS37
VSS38
VSS39
VSS40
VSS41
VSS42
VSS43
VSS44
VSS45
VSS46
VSS47
VSS48
VSS49
VSS50
VSS51
VSS52
VSS53
VSS54
VSS55
VSS56
VSS57
VSS58
VSS59
VSS60
VSS61
VSS62
VSS63
VSS64
VSS65
VSS66
VSS67
VSS68
VSS69
VSS70
VSS71
VSS72
VSS73
VSS74
VSS75
VSS76
VSS77
VSS78
VSS79
VSS80
VSS81
VSS82
VSS83
VSS84
VSS85
VSS86
VSS87
VSS88
VSS89
VSS90
VSS91
VSS92
VSS93
VSS94
VSS95
VSS96
VSS97
VSS98
VSS99
VSS100
VSS101
VSS102
VSS103
VSS104
VSS105
VSS106
VSS107
VSS108
VSS109
VSS110
VSS111
VSS112
VSS113
VSS114
VSS115
VSS116
VSS117
VSS118
VSS119
VSS120
VSS121
VSS122
VSS123
VSS124
VSS125
VSS126
VSS127
VSS128
VSS129
VSS130
VSS131
VSS132
VSS133
VSS134
VSS135
VSS136
VSS137
VSS138
VSS139
VSS140
VSS141
VSS142
VSS143
VSS144
VSS145
VSS146
VSS147
VSS148
VSS149
VSS150
VSS151
VSS152
VSS153
VSS154
VSS155
VSS156
VSS157
VSS158
VSS159
VSS160
VSS161
VSS162
VSS163
VSS164
VSS165
VSS166
VSS167
VSS168
VSS169
VSS170
VSS171
VSS172
VSS173
VSS174
VSS175
VSS176
VSS177
VSS178
VSS179
VSS180
VSS181
VSS182
VSS183
VSS184
VSS185
VSS186
VSS187
VSS188
VSS189
VSS190
VSS191
D13
D15
D17
D19
D21
D23
D26
E3
E6
E8
E10
E12
E14
E16
E18
E20
E22
E25
F1
F4
F5
F7
F9
F11
F13
F15
F17
F19
F21
F24
G2
G6
G22
G23
G26
H3
H5
H21
H25
J1
J4
J6
J22
J24
K2
K5
K21
K23
K26
L3
L6
L22
L25
M1
M4
M5
M21
M24
N3
N6
N22
N23
N26
P2
P5
P21
P24
R1
R4
R6
R22
R25
T3
T5
T21
T23
T26
U2
U6
U22
U24
V1
V4
V5
V21
V25
W3
W6
W22
W23
W26
Y2
Y5
Y21
Y24
U26C
AA11
AA13
AA15
AA17
AA19
AA21
AA5
AA7
AA9
AB10
AB12
AB14
AB16
AB18
AB20
AB22
AB6
AB8
AC11
AC13
AC15
AC17
AC19
AC9
AD10
AD12
AD14
AD16
AD18
AD8
AE11
AE13
AE15
AE17
AE19
AE9
AF10
AF12
AF14
AF16
AF18
AF8
D18
D20
D22
D6
D8
E17
E19
E21
E5
E7
E9
F18
F20
F22
F6
F8
G21
VCC0
VCC1
VCC2
VCC3
VCC4
VCC5
VCC6
VCC7
VCC8
VCC9
VCC10
VCC11
VCC12
VCC13
VCC14
VCC15
VCC16
VCC17
VCC18
VCC19
VCC20
VCC21
VCC22
VCC23
VCC24
VCC25
VCC26
VCC27
VCC28
VCC29
VCC30
VCC31
VCC32
VCC33
VCC34
VCC35
VCC36
VCC37
VCC38
VCC39
VCC40
VCC41
VCC42
VCC43
VCC44
VCC45
VCC46
VCC47
VCC48
VCC49
VCC50
VCC51
VCC52
VCC53
VCC54
VCC55
VCC56
VCC57
VCC58
VCC59
VCC60
VCC61
VCC62
VCC63
VCC64
VCC65
VCC66
VCC67
VCC68
VCC69
VCC70
VCC71
G5
H22
H6
J21
J5
K22
U5
V22
V6
W21
W5
Y22
Y6
VCCA0
VCCA1
VCCA2
VCCA3
F26
B1
N1
AC26
VCCP0
VCCP1
VCCP2
VCCP3
VCCP4
VCCP5
VCCP6
VCCP7
VCCP8
VCCP9
VCCP10
VCCP11
VCCP12
VCCP13
VCCP14
VCCP15
VCCP16
VCCP17
VCCP18
VCCP19
VCCP20
VCCP21
VCCP22
VCCP23
VCCP24
D10
D12
D14
D16
E11
E13
E15
F10
F12
F14
F16
K6
L21
L5
M22
M6
N21
N5
P22
P6
R21
R5
T22
T6
U21
VCCQ0
VCCQ1
P23
W4
VID0
VID1
VID2
VID3
VID4
VID5
4
42 +V1.8S_PROC
+VCCP
3,5,7,15,16,17,37,39,42
3
E2
F2
F3
G3
G4
H4
H_VID0
H_VID1
H_VID2
H_VID3
H_VID4
H_VID5
42
42
42
42
42
42
TPVCSC
VCCSENSE
AE7
VSSSENSE
AF6
TP_VCCSENSE
TPVCC
R110
NO_STUFF_54.9_1%
Pentium M-Processor
LAYOUT NOTE: Provide a test point (with no
stub) to connect differ ential probe
between VCCSENSE and VSS SENSE at the
location where the two 54.9ohm resistors
terminate the 55ohm tranm ission lines.
TPVCCG
TP_VSSSENSE
TPVSS
R112
NO_STUFF_54.9_1%
2
TPVSSG
42 +V1.8S_PROC
7,8,17,41 +V1.8S
One 0.01uF & 10uF cap for each
R395
0
VCCA pin.
C193
C173
C191
C161
C174
C159
C190
C192
0.01UF
0.01UF
0.01UF
0.01UF
10UF
10UF
10UF
10UF
Pentium M-Processor
6,7,9,17,41 +V1.5S
R397
NO_STUFF_0
1
1
Title
Processor 2 of 2
Size Project:
A
855PM Platform
Date:
Monday, February 24, 2003
A
B
C
D
Document Number
Sheet
of
4
E
Rev
47
A
B
C
D
E
CPU Thermal Sensor
+V3.3S
R27
1K
RP3D
10K
4
RP3A
10K
RP3B
10K
3
R20
1K
4
C31
0.1UF
+V3.3S
1
9,10,14,15,17,18,20,23,28,30,31,32,33,36,37,38,41,42
2
9,10,14,15,17,18,20,23,28,30,31,32,33,36,37,38,41,42
RP3C
10K
4
U5
C20
2200PF
ADD0
ADD1
15
SMBDATA
SMBCLK
ALERT#
12
14
11
GND1
GND2
NC1
NC2
NC3
NC4
NC5
1
5
9
13
16
3 H_THERMDC
7
8
NO_STUFF_3Pin_Recepticle
J3
STBY#
6
STBY#
7
VCC
DXP
DXN
ADD0
ADD1
8
2
3
4
10
6
5
3 H_THERMDA
SMB_THRM_DATA 29,34
SMB_THRM_CLK 29,34
THRM_ALERT#
9,10,14,15,17,18,20,23,28,30,31,32,33,36,37,38,41,42
+V3.3S
R311
1.5K
R22
NO_STUFF_0
R309
330
PM_THRM# 16,18,29,34
ADM1023
Layout Note:
Route H_THERMDA and
H_THERMDC on same
layer.
10 mil trace
10 mil spacing
2
THERMDP
+VCCP 3,4,7,15,16,17,37,39,42
1
THERMDN
3
H_PROCHOT#_Q 5
GND0
GND2
3 4 5 6
GND1
GND3
R306
56
H_PROCHOT_S#_D 2
Note: No Stuff R22
and R308 for
Normal Operation
CR12B
3904
R312
330
Thermal Diode Conn
R308
NO_STUFF_0
4
6
3 H_PROCHOT_S#
3
H_PROCHOT#
CR12A
3904
3
1
Note:
If using Thermal Diode
Conn, NO STUFF C20
and U5.
3,4,7,15,16,17,37,39,42
+VCCP
3,4,7,15,16,17,37,39,42
Layout:
Route H_TCK according
to RDDP guidelines
R410
54.9_1%
2
R417
54.9_1%
+VCCP
R421
39.2_1%
3,4,7,15,16,17,37,39,42
+VCCP
2
J46
3
3
3
3
3
TDI_FLEX
H_TMS
H_TCK
H_TDO
H_TRST#
3,7,42 H_CPURST#
R172
R158
R414
R170
0
0
22.6_1%
0
R151
22.6_1%
TMS_FLEX
TCK_FLEX
TDO_FLEX
TRST_FLEX
RESET_FLEX#
3 H_TCK
14 CLK_ITP#
14 CLK_ITP
Note:
All traces between ITP Con
and 0 ohm res must be
short as possible
R171
No_Stuff_330
R413
27.4_1%
R169
680
C455
No_Stuff_75PF
1
2
5
7
3
+V3.3ALWAYS 9,16,17,18,19,20,24,25,26,29,33,34,36,41
TDI
TMS
TCK
TDO
TRST#
VTT0
VTT1
VTAP
27
28
26
12
RESET#
DBR#
DBA#
25
24
ITP_DBRESET# 3,41
11
FBO
BPM0#
BPM1#
BPM2#
BPM3#
BPM4#
BPM5#
23
21
19
17
15
13
H_BPM0_ITP# 3
H_BPM1_ITP# 3
H_BPM2_ITP# 3
H_BPM3_ITP# 3
H_BPM4_PRDY# 3
H_BPM5_PREQ# 3
8
9
BCLKn
BCLKp
10
14
16
18
20
22
GND0
GND1
GND2
GND3
GND4
GND5
NC1
NC2
C216
0.1UF
R139
150
4
6
ITP700-FLEXCON
1
1
Note:
R169 should be place
within 2.0" of the
processor; all others
place near ITP
A
Note:
R171,C455,R172,R158,R170
not needed for Customer
Platforms
B
Title
Size
A
Date:
C
Processor Thermal Sensor & ITP
Document Number
Project:
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
5
of
E
4 7
NOTE:
GRCOMP should be 10
mils wide and less then
0.5" from 855PM
A
2
R382
40.2_1%
9
9
9
9
9
9
9
9
AGP_FRAME#
AGP_DEVSEL#
AGP_IRDY#
AGP_TRDY#
AGP_STOP#
AGP_PAR
AGP_REQ#
AGP_GNT#
R382 use 36.5 Ohm for
55 Ohm board impedance
AGP routing
1
B
14
9
9
9
9
9 AGP_ST0
9 AGP_ST1
9 AGP_ST2
C
9 AGP_SBA[7:0]
Title
D
M_RCV#
SBS0
SBS1
SCS0#
SCS1#
SCS2#
SCS3#
SCKE0
SCKE1
SCKE2
SCKE3
MEMORY
9 AGP_CBE#[3:0]
+V1.8S_MCH 7,8,42
9 AGP_VREF
GRCOMP
CLK_MCH66
AGP_ADSTB0
AGP_ADSTB0#
AGP_ADSTB1
AGP_ADSTB1#
9 AGP_SBSTB
9 AGP_SBSTB#
MCH_TEST#
9 AGP_RBF#
9 AGP_WBF#
9 AGP_PIPE#
Size
Project:
Custom
855PM Platform
Date:
Monday, February 24, 2003
R398
36.5_1%
M_CS3_R#
M_CS2_R#
M_CS1_R#
M_CS0_R#
SMVREF0
SMVREF1
C447
C439
0.1UF
0.1UF
HUB_PD[10:0]
J9
J21
11 M_DQS[8:0]
M_CLK_DDR0
M_CLK_DDR0#
M_CLK_DDR1
M_CLK_DDR1#
M_CLK_DDR2
M_CLK_DDR2#
11 M_CB[7:0]
R404
Sheet
E
DPWR#
10,11,12 M_A[12:0]
DPSLP#
J25
K25
G5
F5
G24
E24
G25
J24
G6
G7
K23
J23
G11
G8
F11
M_DQS0
M_DQS1
M_DQS2
M_DQS3
M_DQS4
M_DQS5
M_DQS6
M_DQS7
M_DQS8
D
Y8
SCK0
SCK0#
SCK1
SCK1#
SCK2
SCK2#
SCK3
SCK3#
SCK4
SCK4#
SCK5
SCK5#
SWE#
SCAS#
SRAS#
F26
C26
C23
B19
D12
C8
C5
E3
E15
42 MCH_RSVD2
V8
AD26
NC0
AD27NC1
J28
SMRCOMP
G15
RCVENIN#
G14 RCVENOUT#
G12
G13
E9
F7
F9
E7
G23
E22
H23
F23
SDQS0
SDQS1
SDQS2
SDQS3
SDQS4
SDQS5
SDQS6
SDQS7
SDQS8
M_DATA0
M_DATA1
M_DATA2
M_DATA3
M_DATA4
M_DATA5
M_DATA6
M_DATA7
M_DATA8
M_DATA9
M_DATA10
M_DATA11
M_DATA12
M_DATA13
M_DATA14
M_DATA15
M_DATA16
M_DATA17
M_DATA18
M_DATA19
M_DATA20
M_DATA21
M_DATA22
M_DATA23
M_DATA24
M_DATA25
M_DATA26
M_DATA27
M_DATA28
M_DATA29
M_DATA30
M_DATA31
M_DATA32
M_DATA33
M_DATA34
M_DATA35
M_DATA36
M_DATA37
M_DATA38
M_DATA39
M_DATA40
M_DATA41
M_DATA42
M_DATA43
M_DATA44
M_DATA45
M_DATA46
M_DATA47
M_DATA48
M_DATA49
M_DATA50
M_DATA51
M_DATA52
M_DATA53
M_DATA54
M_DATA55
M_DATA56
M_DATA57
M_DATA58
M_DATA59
M_DATA60
M_DATA61
M_DATA62
M_DATA63
M_CB0
M_CB1
M_CB2
M_CB3
M_CB4
M_CB5
M_CB6
M_CB7
C
J27 RSTIN#
H27 RSVD1
H26
TESTIN#
HI_0
HI_1
HI_2
HI_3
HI_4
HI_5
HI_6
HI_7
HI_8
HI_9
HI_10
HI_STB
HI_STB#
HLRCOMP
HI_REF
HUB
P25
P24
N27
P23
M26
M25
L28
L27
M27
N28
M24
N25
N24
HUB_RCOMP P27
P26
9 AGP_AD[31:0]
AE22 RBF#
AE23 WBF#
AF22 PIPE#
AG25ST0
AF24 ST1
AG26ST2
AH28SBA0
AH27SBA1
AG28SBA2
AG27SBA3
AE28 SBA4
AE27 SBA5
AE24 SBA6
AE25 SBA7
AF27 SB_STB
AF26 SB_STB#
R24 AD_STB0
R23 AD_STB0#
AC27AD_STB1
AC28AD_STB1#
G28
F27
C28
E28
H25
G27
F25
B28
E27
C27
B25
C25
B27
D27
D26
E25
D24
E23
C22
E21
C24
B23
D22
B21
C21
D20
C19
D18
C20
E19
C18
E17
E13
C12
B11
C10
B13
C13
C11
D10
E10
C9
D8
E8
E11
B9
B7
C7
C6
D6
D4
B3
E6
B5
C4
E4
C3
D3
F4
F3
B2
C2
E2
G4
C16
D16
B15
C14
B17
C17
C15
D14
M_A0
M_A1
M_A2
M_A3
M_A4
M_A5
M_A6
M_A7
M_A8
M_A9
M_A10
M_A11
M_A12
M_DATA[63:0] 11
HUB_PD0
HUB_PD1
HUB_PD2
HUB_PD3
HUB_PD4
HUB_PD5
HUB_PD6
HUB_PD7
HUB_PD8
HUB_PD9
HUB_PD10
AGP_SBA0
AGP_SBA1
AGP_SBA2
AGP_SBA3
AGP_SBA4
AGP_SBA5
AGP_SBA6
AGP_SBA7
AGP
Y24 GFRAME#
W28 GDEVSEL#
W27 GIRDY#
W24 GTRDY#
W23 GSTOP#
W25 GPAR
AG24GREQ#
AH25GGNT#
AD25GRCOMP
AA21 AGPREF
P22 66IN
SDQ0
SDQ1
SDQ2
SDQ3
SDQ4
SDQ5
SDQ6
SDQ7
SDQ8
SDQ9
SDQ10
SDQ11
SDQ12
SDQ13
SDQ14
SDQ15
SDQ16
SDQ17
SDQ18
SDQ19
SDQ20
SDQ21
SDQ22
SDQ23
SDQ24
SDQ25
SDQ26
SDQ27
SDQ28
SDQ29
SDQ30
SDQ31
SDQ32
SDQ33
SDQ34
SDQ35
SDQ36
SDQ37
SDQ38
SDQ39
SDQ40
SDQ41
SDQ42
SDQ43
SDQ44
SDQ45
SDQ46
SDQ47
SDQ48
SDQ49
SDQ50
SDQ51
SDQ52
SDQ53
SDQ54
SDQ55
SDQ56
SDQ57
SDQ58
SDQ59
SDQ60
SDQ61
SDQ62
SDQ63
SDQ64
SDQ65
SDQ66
SDQ67
SDQ68
SDQ69
SDQ70
SDQ71
855PM-MCH_Rev005A
SMA0 E12
F17
SMA1
SMA2 E16
G17
SMA3
SMA4 G18
E18
SMA5
SMA6 F19
G20
SMA7
SMA8 G19
F21
SMA9
SMA10 F13
E20
SMA11
SMA12 G21
RSVD2 G22
3
B
M_RCOMP
U28A
R27 GAD0
R28
GAD1
T25 GAD2
R25
GAD3
T26 GAD4
T27
GAD5
U27 GAD6
U28 GAD7
V26 GAD8
V27
GAD9
T23 GAD10
U23
GAD11
T24 GAD12
U24 GAD13
U25 GAD14
V24
GAD15
Y27 GAD16
Y26 GAD17
AA28 GAD18
AB25
GAD19
AB27 GAD20
AA27 GAD21
AB26 GAD22
Y23 GAD23
AB23 GAD24
AA24 GAD25
AA25 GAD26
AB24
GAD27
AC25GAD28
AC24
GAD29
AC22GAD30
AD24
GAD31
4
AGP_CBE#0 V25
AGP_CBE#1 V23 GCBE0#
AGP_CBE#2 Y25 GCBE1#
AGP_CBE#3 AA23 GCBE2#
GCBE3#
AGP_AD0
AGP_AD1
AGP_AD2
AGP_AD3
AGP_AD4
AGP_AD5
AGP_AD6
AGP_AD7
AGP_AD8
AGP_AD9
AGP_AD10
AGP_AD11
AGP_AD12
AGP_AD13
AGP_AD14
AGP_AD15
AGP_AD16
AGP_AD17
AGP_AD18
AGP_AD19
AGP_AD20
AGP_AD21
AGP_AD22
AGP_AD23
AGP_AD24
AGP_AD25
AGP_AD26
AGP_AD27
AGP_AD28
AGP_AD29
AGP_AD30
AGP_AD31
A
E
M_WE# 10,11,12
M_CAS# 10,11,12
M_RAS# 10,11,12
10
10
10
10
10
10
TP_U22_NC_0
TP_U22_NC_1
M_BS1# 10,11,12
M_BS0# 10,11,12
M_CKE3_R 10,12
M_CKE2_R 10,12
M_CKE1_R 10,12,42
M_CKE0_R 10,12,42
Document Number
6
4
M_CLK_DDR3 10
M_CLK_DDR3# 10
M_CLK_DDR4 10
M_CLK_DDR4# 10
M_CLK_DDR5 10
M_CLK_DDR5# 10
SM_VREF_MCH 40
3
MEMORY
H_DPSLP# 3,15,34
H_DPWR# 3
Layout:
Provide Via on M_RCV#
for measurement
12,13,40,42
30.1_1%
4,7,9,17,41
of
+V1.25S
10,12
10,12
10,12,42
10,12,42
MCH_RSVD1 42
PCI_RST# 15,23,28,34,42
HUB_VREF_MCH 8
HUB_PSTRB# 8,15
HUB_PSTRB 8,15
8,15
855PM MCH (1 of 3)
Rev
4
7
2
C213
0.1UF
+V1.5S
R405
NO_STUFF_4.7K
1
A
B
C
D
E
H_D#[63:0] 3
U28B
0.01_1%
37,39 +V1.2S_MCH
6,8,42 +V1.8S_MCH
3
R122
0.01_1%
2
VCC0
VCC1
VCC2
VCC3
VCC4
VCC5
VCC6
VCC7
VCC8
VCC9
L25
L29
M22
N23
N26
VCCHL0
VCCHL1
VCCHL2
VCCHL3
VCCHL4
VCCSM0
VCCSM1
VCCSM2
VCCSM3
VCCSM4
VCCSM5
VCCSM6
VCCSM7
VCCSM8
VCCSM9
VCCSM10
VCCSM11
VCCSM12
VCCSM13
VCCSM14
VCCSM15
VCCSM16
VCCSM17
VCCSM18
VCCSM19
VCCSM20
VCCSM21
VCCSM22
VCCSM23
VCCSM24
VCCSM25
VCCSM26
VCCSM27
VCCSM28
VCCSM29
VCCSM30
VCCSM31
VCCSM32
VCCSM33
VCCSM34
VCCSM35
VCCSM36
VCCSM37
R422
NO_STUFF_10K
6,8,42 +V1.8S_MCH
G16
G10
G9
H7
H4
H3
G3
G2
RSVD3
RSVD4
RSVD5
RSVD6
ETS#
RSVD7
RSVD8
RSVD9
T17
T13
VCCGA
VCCHA
U7
V4
W2
Y4
Y3
Y5
W3
V7
V3
Y7
V5
W7
W5
W6
AB10
AB14
AB18
AB20
AB8
AC19
AD18
AD20
AE19
AE21
AF18
AF20
AG19
AG21
AG23
AJ19
AJ21
AJ23
M8
T8
H_REQ#0
H_REQ#1
H_REQ#2
H_REQ#3
H_REQ#4
3 H_ADSTB#0
3 H_ADSTB#1
U2
T7
R7
U5
T4
R5
N7
HREQ0#
HREQ1#
HREQ2#
HREQ3#
HREQ4#
HADSTB0#
HADSTB1#
A13
A17
A21
A25
A5
A9
C1
C29
D11
D15
D19
D23
D25
D7
E5
F10
F14
F16
F18
F22
G1
G29
H10
H12
H14
H16
H18
H20
H22
H24
H5
H8
J6
K22
K24
K26
K7
L23
HRCOMP1
HSWING1
HRCOMP0
HSWING0
K8
J8
AC13
AD13
AC2
AA7
BCLK#
BCLK
HRCOMP1
HSWNG1
HRCOMP0
HSWNG0
AD4
AF6
AD11
AC15
AD3
AG6
AE11
AC16
AD5
AG5
AH9
AD15
HDSTBN0#
HDSTBN1#
HDSTBN2#
HDSTBN3#
HDSTBP0#
HDSTBP1#
HDSTBP2#
HDSTBP3#
DBI0#
DBI1#
DBI2#
DBI3#
AE17
CPURST#
M7
P8
AA9
AB12
AB16
HVREF0
HVREF1
HVREF2
HVREF3
HVREF4
H_ADS# 3
H_TRDY# 3
H_DRDY# 3
H_DEFER# 3
H_HITM# 3
H_HIT# 3
H_LOCK# 3
H_BR0# 3
H_BNR# 3
H_BPRI# 3
H_DBSY# 3
H_RS#0
H_RS#1
H_RS#2
H_RS#[2:0] 3
+VCCP
3,4,5,15,16,17,37,39,42
+V2.5_MCH
8,40
+VCCP
3,4,5,15,16,17,37,39,42
3 H_REQ#[4:0]
R380
301_1%
14 CLK_MCH_BCLK#
C404
0.01UF
R133
49.9_1%
14 CLK_MCH_BCLK
R383
150_1%
R132
HSWING[1:0]
18 mil trace
10 mil space
3,4,5,15,16,17,37,39,42
R389
27.4_1%
3
3
3
3
3
3
3
3
3
3
3
3
R384
27.4_1%
+VCCP
R394
301_1%
C415
0.01UF
LAYOUT NOTE:
H_CPURST# forks
at 855PM pin
3,5,42 H_CPURST#
R393
150_1%
H_DSTBN#0
H_DSTBN#1
H_DSTBN#2
H_DSTBN#3
H_DSTBP#0
H_DSTBP#1
H_DSTBP#2
H_DSTBP#3
H_DINV#0
H_DINV#1
H_DINV#2
H_DINV#3
3,5,42 H_CPURST#
3,4,5,15,16,17,37,39,42
+VCCP
+VCCP 3,4,5,15,16,17,37,39,42
R3003
49.9_1%
1
1
49.9_1%
2 MCH_REF3
3
J3002
NO_STUFF_CON3_HDR
3
NOTE:
Max length of
MCH_GTLREF is
0.5"
2 MCH_GTLREF_D
R392
NO_STUFF_0
J24
NO_STUFF_CON3_HDR
3,4,5,15,16,17,37,39,42
HD0#
HD1#
HD2#
HD3#
HD4#
HD5#
HD6#
HD7#
HD8#
HD9#
HD10#
HD11#
HD12#
HD13#
HD14#
HD15#
HD16#
HD17#
HD18#
HD19#
HD20#
HD21#
HD22#
HD23#
HD24#
HD25#
HD26#
HD27#
HD28#
HD29#
HD30#
HD31#
HD32#
HD33#
HD34#
HD35#
HD36#
HD37#
HD38#
HD39#
HD40#
HD41#
HD42#
HD43#
HD44#
HD45#
HD46#
HD47#
HD48#
HD49#
HD50#
HD51#
HD52#
HD53#
HD54#
HD55#
HD56#
HD57#
HD58#
HD59#
HD60#
HD61#
HD62#
HD63#
AA2
AB5
AA5
AB3
AB4
AC5
AA3
AA6
AE3
AB7
AE5
AF3
AC6
AC3
AF4
AE2
AG4
AG2
AE7
AE8
AH2
AC7
AG3
AD7
AH7
AE6
AC8
AG8
AG7
AH3
AF8
AH5
AC11
AC12
AE9
AC10
AE10
AD9
AG9
AC9
AE12
AF10
AG11
AG10
AH11
AG12
AE13
AF12
AG13
AH13
AC14
AF14
AG14
AE14
AG15
AG16
AG17
AH15
AC17
AF16
AE15
AH17
AD17
AE16
H_D#0
H_D#1
H_D#2
H_D#3
H_D#4
H_D#5
H_D#6
H_D#7
H_D#8
H_D#9
H_D#10
H_D#11
H_D#12
H_D#13
H_D#14
H_D#15
H_D#16
H_D#17
H_D#18
H_D#19
H_D#20
H_D#21
H_D#22
H_D#23
H_D#24
H_D#25
H_D#26
H_D#27
H_D#28
H_D#29
H_D#30
H_D#31
H_D#32
H_D#33
H_D#34
H_D#35
H_D#36
H_D#37
H_D#38
H_D#39
H_D#40
H_D#41
H_D#42
H_D#43
H_D#44
H_D#45
H_D#46
H_D#47
H_D#48
H_D#49
H_D#50
H_D#51
H_D#52
H_D#53
H_D#54
H_D#55
H_D#56
H_D#57
H_D#58
H_D#59
H_D#60
H_D#61
H_D#62
H_D#63
+V3.3
A
Title
J47
NO_STUFF_CON3_HDR
Size
A
Date:
B
C
3
2
R391
49.9_1%
MCH_GTLREF
C411
C429
C427
1UF
220PF
220PF
R390
100_1%
1
R3004
100_1%
3
9,15,17,20,24,27,29,32,34,36,40,41
4
+VCCP
2
C424
10UF
1
1
C420
0.1UF
MCH_RSVD3
MCH_RSVD4
MCH_RSVD5
MCH_RSVD6
MCH_ETS#
MCH_RSVD7
MCH_RSVD8
MCH_RSVD9
ADS#
HTRDY#
DRDY#
DEFER#
HITM#
HIT#
HLOCK#
BR0
BNR#
BPRI#
DBSY#
RS0#
RS1#
RS2#
VTT0
VTT1
VTT2
VTT3
VTT4
VTT5
VTT6
VTT7
VTT8
VTT9
VTT10
VTT11
VTT12
VTT13
VTT14
VTT15
VTT16
VTT17
VTT18
VTT19
8,40 +V2.5_MCH
42
42
42
42
42
42
42
42
HA3#
HA4#
HA5#
HA6#
HA7#
HA8#
HA9#
HA10#
HA11#
HA12#
HA13#
HA14#
HA15#
HA16#
HA17#
HA18#
HA19#
HA20#
HA21#
HA22#
HA23#
HA24#
HA25#
HA26#
HA27#
HA28#
HA29#
HA30#
HA31#
HOST
4,8,17,41 +V1.8S
N14
N16
P13
P15
P17
R14
R16
T15
U14
U16
U6
T5
R2
U3
R3
P7
T3
P4
P3
P5
R6
N2
N5
N3
J3
M3
M4
M5
L5
K3
J2
N6
L6
L2
K5
L3
L7
K4
J5
855PM_MCH_Rev005A
VCCAGP0
VCCAGP1
VCCAGP2
VCCAGP3
VCCAGP4
VCCAGP5
VCCAGP6
VCCAGP7
VCCAGP8
VCCAGP9
VCCAGP10
VCCAGP11
VCCAGP12
VCCAGP13
VCCAGP14
VCCAGP15
HOST
AA22
AA26
R22
R29
U22
U26
W22
W29
AB21
AC29
AD21
AD23
AE26
AF23
AG29
AJ25
H_A#3
H_A#4
H_A#5
H_A#6
H_A#7
H_A#8
H_A#9
H_A#10
H_A#11
H_A#12
H_A#13
H_A#14
H_A#15
H_A#16
H_A#17
H_A#18
H_A#19
H_A#20
H_A#21
H_A#22
H_A#23
H_A#24
H_A#25
H_A#26
H_A#27
H_A#28
H_A#29
H_A#30
H_A#31
1
R116
4
3 H_A#[31:3]
8 +V1.5S_MCH
855PM_MCH_Rev005A
2
+V1.5S
MCH_REF2
4,6,9,17,41
U28C
855PM MCH (2 of 3)
Project:
Document Number
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
7
of
E
4 7
A
B
C
D
E
14,15 CLK_ICH66
Layout:Place
0 Ohm close
to "T"
R412
NO_STUFF_0
J101
Test CAP's backside
CLK_ICH66_D
1
HUB_PD1
HUB_PD2
HUB_PD3
HUB_PD9
6,15 HUB_PSTRB
6,15 HUB_PSTRB#
HUB_PD10
HUB_PD8
HUB_PD4
HUB_PD5
HUB_PD6
HUB_PD7
4
C322
220PF
TP_330pf1
1
TP_330pf2
2
C319
330PF
TP_.1uf1
TP_.1uf2
C321
0.1UF
TP_BS_100pf1
TP_BS_100pf2
C534
0.015uF
+V1.8S 4,7,17,41
TP_BS_.01uf1
C317
0.082uF
TP_BS_.01uf2
TP_.47uf1 1
TP_BS_0.1uf2
TP_BS_0.1uf1
TP_.082uf2
TP_.082uf1
C536
0.01UF
TP_.47uf2
2
C320
0.47uF
TP_.01uf2
TP_.01uf1
C537
0.1UF
C318
0.01UF
3
TP_BS_220pf1
6,15 HUB_PD[10:0]
TP_BS_1000pF1
LAI HUB
INTERFACE
TP_.1uf3
TP_BS_220pf2
C538
220PF
NO_STUFF_50Pin_SKT
TP_.1uf4
C315
0.1uF
10%
TP_BS_1000pF2
C535
1000PF
TP_R1
TP_R2
7,40 +V2.5_MCH
R3010
NO_STUFF_0.02_1%
C217
22UF
C241
22UF
C445
0.1UF
C444
0.1UF
C233
0.1UF
C232
0.1UF
C228
0.1UF
C222
0.1UF
C446
0.1UF
C214
0.1UF
C229
0.1UF
C230
0.1UF
C443
0.1UF
C442
0.1UF
+V1.8S_MCH
C441
0.1UF
C440
0.1UF
C231
0.1UF
C215
150uF
HUB_VREF_MCH 6
C242
150uF
R402
150_1%
+V1.8S_MCH 6,7,42
R408
0
J36
2
7 +V1.5S_MCH
J37
C428
+
C170
C179
100uF
10UF
0.01UF
C178
10UF
C423 6,7,42 +V1.8S_MCH
0.1UF
1
1
2
R409
150_1%
NO_STUFF_CON3_HDR
C416
0.1UF
C397
0.1UF
C421
0.1UF
C418
0.1UF
10UF
C436
0.1UF
C437
0.1UF
C430
0.1UF
(1/2) 1.8V
C448
NO_STUFF_470PF
2
R407
NO_STUFF_56.2_1%
HUB_VREF_M
C206
C419
0.1UF
HUB INTERFACE
REFERENCE
6,7,42
Do Not Stuff
3
R406
0
C451
0.01UF
PLACE C428
NEAR MCH
1
Title
Size
A
Date:
A
TP_220pf2
TP_220pf1
HUB_VREF_L
855PM_MCH_Rev005A
VSS71 E14
VSS72 E26
VSS73 E29
VSS74 F12
VSS75 F15
VSS76 F20
VSS77 F24
VSS78 F6
VSS79 F8
VSS80 G26
VSS81 H11
VSS82 H13
VSS83 H15
VSS84 H17
VSS85 H19
VSS86 H21
VSS87 H6
VSS88 H9
VSS89 J1
VSS90 J22
VSS91 J26
VSS92 J29
VSS93 J4
VSS94 J7
VSS95 K27
VSS96 K6
VSS97 L1
VSS98 L22
VSS99 L24
VSS100 L26
VSS101 L4
VSS102 L8
VSS103 M23
VSS104 M6
VSS105 N1
VSS106 N13
VSS107 N15
VSS108 N17
VSS109 N22
VSS110 N29
VSS111 N4
VSS112 N8
VSS113 P14
VSS114 P16
VSS115 P6
VSS116 R1
VSS117 R13
VSS118 R15
VSS119 R17
VSS120 R26
VSS121 R4
VSS122 R8
VSS123 T14
VSS124 T16
VSS125 T22
VSS126 T6
VSS127 U1
VSS128 U13
VSS129 U15
VSS130 U17
VSS131 U29
VSS132 U4
VSS133 U8
VSS134 V22
VSS135 V6
VSS136 W1
VSS137 W26
VSS138 W4
VSS139 W8
VSS140 Y22
VSS141 Y6
HUB_VREF_U
2
VSS0
VSS1
VSS2
VSS3
VSS4
VSS5
VSS6
VSS7
VSS8
VSS9
VSS10
VSS11
VSS12
VSS13
VSS14
VSS15
VSS16
VSS17
VSS18
VSS19
VSS20
VSS21
VSS22
VSS23
VSS24
VSS25
VSS26
VSS27
VSS28
VSS29
VSS30
VSS31
VSS32
VSS33
VSS34
VSS35
VSS36
VSS37
VSS38
VSS39
VSS40
VSS41
VSS42
VSS43
VSS44
VSS45
VSS46
VSS47
VSS48
VSS49
VSS50
VSS51
VSS52
VSS53
VSS54
VSS55
VSS56
VSS57
VSS58
VSS59
VSS60
VSS61
VSS62
VSS63
VSS64
VSS65
VSS66
VSS67
VSS68
VSS69
VSS70
HUB_VREF_MCH 6
range for R401, R405: 100 - 150 ohm
3
U28D
A11
A15
A19
A23
A27
A3
A7
AA1
AA29
AA4
AA8
AB11
AB13
AB15
AB17
AB19
AB22
AB6
AB9
AC1
AC18
AC20
AC21
AC23
AC26
AC4
AD10
AD12
AD14
AD16
AD19
AD22
AD6
AD8
AE1
AE18
AE20
AE29
AE4
AF11
AF13
AF15
AF17
AF19
AF21
AF25
AF5
AF7
AF9
AG1
AG18
AG20
AG22
AH19
AH21
AH23
AJ11
AJ13
AJ15
AJ17
AJ27
AJ3
AJ5
AJ7
AJ9
D13
D17
D21
D5
D9
E1
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
39
41
43
45
47
49
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
42
44
46
48
50
HUB_PD0
4
Test CAP's topside
B
C
855PM MCH (3 of 3)
Project:
Document Number
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
8
of
E
4 7
A
B
C
D
E
MCH Straps
+V3.3ALWAYS
4
3
+V1.5S_AGP
R123 R119
8.2K
8.2K
6 AGP_ADSTB1#
6 AGP_ADSTB1
6 AGP_ADSTB0#
6 AGP_ADSTB0
6 AGP_SBSTB#
6 AGP_SBSTB
14 CLK_AGP_SLOT
AGP_PERR#
AGP_SERR#
6 AGP_DEVSEL#
A65
B65
A63
B63
A62
B62
A60
B60
B57
A56
B56
A54
B54
A53
B53
A51
A39
B38
A38
B36
A36
B35
A35
B33
A30
B30
A29
B29
A27
B27
A26
B26
AD0
AD1
AD2
AD3
AD4
AD5
AD6
AD7
AD8
AD9
AD10
AD11
AD12
AD13
AD14
AD15
AD16
AD17
AD18
AD19
AD20
AD21
AD22
AD23
AD24
AD25
AD26
AD27
AD28
AD29
AD30
AD31
A32
B32
A59
B59
A18
B18
AD_STB1#
AD_STB1
AD_STB0#
AD_STB0
SB_STB#
SB_STB
B7
PERR#
SERR#
B46
DEVSEL#
B8
6 AGP_REQ#
6 AGP_FRAME#
6 AGP_GNT#
2
6 AGP_IRDY#
AGP_RST#
A41
GNT#
IRDY#
A7
RST#
A46
6 AGP_RBF#
6 AGP_WBF#
B12
A14
RBF#
WBF#
TYPEDET#
A47
STOP#
15,18,19,20,21 INT_PIRQB#
15,18,19,20,21 INT_PIRQA#
B6
A6
INTB#
INTA#
B1
OVRCNT#
A50
PAR
6 AGP_ST0
6 AGP_ST1
6 AGP_ST2
B10
A10
B11
ST0
ST1
ST2
6 AGP_PIPE#
A12
PIPE#
15,19,20,34 PCI_PME#
A48
PME#
A4
B4
USBUSB+
A
VCC3.3_1
VCC3.3_2
VCC3.3_3
VCC3.3_4
VCC3.3_5
VCC3.3_6
VCC3.3_7
VCC3.3_8
B9
B16
B25
B28
A9
A16
A25
A28
VDDQ1
VDDQ2
B52
A52
VDDQ1.5_1
VDDQ1.5_2
VDDQ1.5_3
VDDQ1.5_4
VDDQ1.5_5
VDDQ1.5_6
VDDQ1.5_7
VDDQ1.5_8
VDDQ1.5_9
B34
B40
B47
B58
B64
A34
A40
A58
A64
Vrefcg
Vrefgc
B66
A66
SBA0
SBA1
SBA2
SBA3
SBA4
SBA5
SBA6
SBA7
B15
A15
B17
A17
B20
A20
B21
A21
AGP_SBA0
AGP_SBA1
AGP_SBA2
AGP_SBA3
AGP_SBA4
AGP_SBA5
AGP_SBA6
AGP_SBA7
C/BE0#
C/BE1#
C/BE2#
C/BE3#
A57
B51
B39
A33
AGP_CBE#0
AGP_CBE#1
AGP_CBE#2
AGP_CBE#3
Mobile AGP
Sideband
Header
14,18,20,24,34,41
R376
8.2K
C98
0.1UF
+V3.3S_AGP
1
2
3
4
5
6
16,34 PM_C3_STAT#
16,29,31,34 PM_SUS_STAT#
+V1.5S_AGP
ST1
ST0
X
0
1
1
X
X
D3
Cold
Core Power
STUFF
R95 (V3S)
NO_STUFF
R84 (V3)
IO Rail
R114 (V1.5S) STUFF
R154 (V1.5) NO_STUFF
RESET
STUFF
R75
R76 (Gated) NO_STUFF
R129
1K_1%
AGP_VREF 6
C449
0.1UF
Hot
On
DEFAULT
+V1.5S 4,6,7,17,41
C414
0.1UF
DDR
Test Mode
400 Mhz BPSB
4
6Pin_HDR
R131
1K_1%
MCH STRAP
For AGP D3 HOT and ON:
AGP_BUSY# need pullup
to +V3.3S instead to
prevent leakage in S3
J44
16 AGP_BUSY#
NO_STUFF NO_STUFF
STUFF
STUFF
STUFF
NO_STUFF
NO_STUFF STUFF
NO_STUFF NO_STUFF
STUFF
STUFF
J42
Measurement Point
3
R75
15,19,20,21,29,30,31,34 BUF_PCI_RST#
0
R76
NO_STUFF_0
19,20,29,34 PCI_GATED_RST#
AGP_RST#
Place near Place near
MCH
AGP
AGP_SBA[7:0] 6
4,6,7,17,41 +V1.5S
AGP_CBE#[3:0] 6
17,20,21,24,31,32,33,35,36,37,38,41,42
+V5S_AGP
C97
22UF
R374
1K
+V5S
C102
C107
R375
1K
+V1.5S 4,6,7,17,41
R89
+V1.5 17
0.01_1%
AGP_ST2
AGP_ST1
R154
R114
NO_STUFF_0.01_1%
0.01_1%
0.1UF
0.1UF
2
R373
NO_STUFF_1K
+V1.5S_AGP
TRDY#
6 AGP_STOP#
6 AGP_PAR
+V3.3S_AGP
+V12S
B24
B3
B2
A1
FRAME#
A8
6 AGP_TRDY#
+V5S_AGP
3.3Vaux
5.0V2
5.0V1
12V
REQ#
B41
A2
1
CLK
B48
B50
124Pin_AGP-Rev2.0
2
AGP_AD0
AGP_AD1
AGP_AD2
AGP_AD3
AGP_AD4
AGP_AD5
AGP_AD6
AGP_AD7
AGP_AD8
AGP_AD9
AGP_AD10
AGP_AD11
AGP_AD12
AGP_AD13
AGP_AD14
AGP_AD15
AGP_AD16
AGP_AD17
AGP_AD18
AGP_AD19
AGP_AD20
AGP_AD21
AGP_AD22
AGP_AD23
AGP_AD24
AGP_AD25
AGP_AD26
AGP_AD27
AGP_AD28
AGP_AD29
AGP_AD30
AGP_AD31
1
J26
6 AGP_AD[31:0]
5,16,17,18,19,20,24,25,26,29,33,34,36,41
RSVD1
RSVD2
RSVD3
RSVD4
RSVD5
RSVD6
GND1
GND2
GND3
GND4
GND5
GND6
GND7
GND8
GND9
GND10
GND11
GND12
GND13
GND14
GND15
GND16
GND17
GND18
B14
B22
A3
A11
A22
A24
B5
B13
B19
B23
B31
B37
B49
B55
B61
A5
A13
A19
A23
A31
A37
A49
A55
A61
B
C188
C212
NO_STUFF_150uF
NO_STUFF_150uF
+
C168
100uF
C180
22UF
C207
C209
C201
C177
C152
C204
C211
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
5,10,14,15,17,18,20,23,28,30,31,32,33,36,37,38,41,42
+V3.3S
7,15,17,20,24,27,29,32,34,36,40,41 +V3.3
R95
R84
+V3.3S_AGP
C151
22UF
22UF
+ C158
2
0.002
1%
NO_STUFF_01_1%
1
C157
100uF
C142
C162
C147
0.1UF
0.1UF
0.1UF
AGP CONN
1
Title
Size
A
Date:
C
AGP 1.5V Connector
Document Number
Project:
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
of
9
E
47
A
B
C
D
E
13,40 +V2.5_DDR
5,9,14,15,17,18,20,23,28,30,31,32,33,36,37,38,41,42
+V3.3S
+V3.3S_SPD
R500
0.01_1%
11,12 M_DATA_R_[63:0]
J64A
11 M_A_FR_[12:0]
M_A_FR_0
M_A_FR_1
M_A_FR_2
M_A_FR_3
M_A_FR_4
M_A_FR_5
M_A_FR_6
M_A_FR_7
M_A_FR_8
M_A_FR_9
M_A_FR_10
M_A_FR_11
M_A_FR_12
4
42 DDR_RSVD3
11 M_BS0_FR#
11 M_BS1_FR#
11,12 M_CB_R[7:0]
3
6
6
6
6
6
6
6,12,42
6,12,42
11
11
11
6,12,42
6,12,42
M_CB_R0
M_CB_R1
M_CB_R2
M_CB_R3
M_CB_R4
M_CB_R5
M_CB_R6
M_CB_R7
M_CLK_DDR0
M_CLK_DDR0#
M_CLK_DDR1#
M_CLK_DDR1
M_CLK_DDR2
M_CLK_DDR2#
M_CKE0_R
M_CKE1_R
M_CAS_FR#
M_RAS_FR#
M_WE_FR#
M_CS0_R#
M_CS1_R#
14,15,18,21 SMB_CLK
14,15,18,21 SMB_DATA
2
11,12 M_DQS_R[8:0]
M_DQS_R0
M_DQS_R1
M_DQS_R2
M_DQS_R3
M_DQS_R4
M_DQS_R5
M_DQS_R6
M_DQS_R7
M_DQS_R8
CON200_DDR-SODIMM
112
111
110
109
108
107
106
105
102
101
115
100
99
97
A0
A1
A2
A3
A4
A5
A6
A7
A8
A9
A10/AP
A11
A12
A13(DU)
117
116
98
71
73
79
83
72
74
80
84
35
37
158
160
89
91
96
95
120
118
119
121
122
194
196
198
195
193
86
BA0
BA1
BA2(DU)
CB0
CB1
CB2
CB3
CB4
CB5
CB6
CB7
CK0
CK0#
CK1#
CK1
CK2
CK2#
CKE0
CKE1
CAS#
RAS#
WE#
S0#
S1#
SA0
SA1
SA2
SCL
SDA
RESET(DU)
12
26
48
62
134
148
170
184
78
DM0
DM1
DM2
DM3
DM4
DM5
DM6
DM7
DM8
11
25
47
61
133
147
169
183
77
DQS0
DQS1
DQS2
DQS3
DQS4
DQS5
DQS6
DQS7
DQS8
5
7
13
17
6
8
14
18
19
23
29
31
20
24
30
32
41
43
49
53
42
44
50
54
55
59
65
67
56
60
66
68
127
129
135
139
128
130
136
140
141
145
151
153
142
146
152
154
163
165
171
175
164
166
172
176
177
181
187
189
178
182
188
190
DQ0
DQ1
DQ2
DQ3
DQ4
DQ5
DQ6
DQ7
DQ8
DQ9
DQ10
DQ11
DQ12
DQ13
DQ14
DQ15
DQ16
DQ17
DQ18
DQ19
DQ20
DQ21
DQ22
DQ23
DQ24
DQ25
DQ26
DQ27
DQ28
DQ29
DQ30
DQ31
DQ32
DQ33
DQ34
DQ35
DQ36
DQ37
DQ38
DQ39
DQ40
DQ41
DQ42
DQ43
DQ44
DQ45
DQ46
DQ47
DQ48
DQ49
DQ50
DQ51
DQ52
DQ53
DQ54
DQ55
DQ56
DQ57
DQ58
DQ59
DQ60
DQ61
DQ62
DQ63
M_DATA_R_0
M_DATA_R_1
M_DATA_R_2
M_DATA_R_3
M_DATA_R_4
M_DATA_R_5
M_DATA_R_6
M_DATA_R_7
M_DATA_R_8
M_DATA_R_9
M_DATA_R_10
M_DATA_R_11
M_DATA_R_12
M_DATA_R_13
M_DATA_R_14
M_DATA_R_15
M_DATA_R_16
M_DATA_R_17
M_DATA_R_18
M_DATA_R_19
M_DATA_R_20
M_DATA_R_21
M_DATA_R_22
M_DATA_R_23
M_DATA_R_24
M_DATA_R_25
M_DATA_R_26
M_DATA_R_27
M_DATA_R_28
M_DATA_R_29
M_DATA_R_30
M_DATA_R_31
M_DATA_R_32
M_DATA_R_33
M_DATA_R_34
M_DATA_R_35
M_DATA_R_36
M_DATA_R_37
M_DATA_R_38
M_DATA_R_39
M_DATA_R_40
M_DATA_R_41
M_DATA_R_42
M_DATA_R_43
M_DATA_R_44
M_DATA_R_45
M_DATA_R_46
M_DATA_R_47
M_DATA_R_48
M_DATA_R_49
M_DATA_R_50
M_DATA_R_51
M_DATA_R_52
M_DATA_R_53
M_DATA_R_54
M_DATA_R_55
M_DATA_R_56
M_DATA_R_57
M_DATA_R_58
M_DATA_R_59
M_DATA_R_60
M_DATA_R_61
M_DATA_R_62
M_DATA_R_63
6,11,12 M_A[12:0]
M_A0
M_A1
M_A2
M_A3
M_A4
M_A5
M_A6
M_A7
M_A8
M_A9
M_A10
M_A11
M_A12
42 DDR_RSVD2
6,11,12 M_BS0#
6,11,12 M_BS1#
11,12 M_CB_R[7:0]
M_CB_R0
M_CB_R1
M_CB_R2
M_CB_R3
M_CB_R4
M_CB_R5
M_CB_R6
M_CB_R7
+V3.3S_SPD
6 M_CLK_DDR3
6 M_CLK_DDR3#
6 M_CLK_DDR4#
6 M_CLK_DDR4
6 M_CLK_DDR5
6 M_CLK_DDR5#
6,12 M_CKE2_R
6,12 M_CKE3_R
6,11,12 M_CAS#
6,11,12 M_RAS#
6,11,12 M_WE#
6,12 M_CS2_R#
6,12 M_CS3_R#
14,15,18,21 SMB_CLK
14,15,18,21 SMB_DATA
RSVD5
112
111
110
109
108
107
106
105
102
101
115
100
99
97
117
116
98
71
73
79
83
72
74
80
84
35
37
158
160
89
91
96
95
120
118
119
121
122
194
196
198
195
193
86
12
26
48
62
134
148
170
184
78
11,12 M_DQS_R[8:0]
M_DQS_R0
M_DQS_R1
M_DQS_R2
M_DQS_R3
M_DQS_R4
M_DQS_R5
M_DQS_R6
M_DQS_R7
M_DQS_R8
SO DIMM 0
11
25
47
61
133
147
169
183
77
J72A CON200_DDR-SODIMM_REV
A0
DQ0 5
A1
DQ1 7
A2
DQ2 13
A3
DQ3 17
A4
DQ4 6
A5
DQ5 8
A6
DQ6 14
A7
DQ7 18
A8
DQ8 19
A9
DQ9 23
A10/AP
DQ10 29
A11
DQ11 31
A12
DQ12 20
A13(DU)
DQ13 24
DQ14 30
BA0
DQ15 32
BA1
DQ16 41
BA2(DU)
DQ17 43
CB0
DQ18 49
CB1
DQ19 53
CB2
DQ20 42
CB3
DQ21 44
CB4
DQ22 50
CB5
DQ23 54
CB6
DQ24 55
CB7
DQ25 59
CK0
DQ26 65
CK0#
DQ27 67
CK1#
DQ28 56
CK1
DQ29 60
CK2
DQ30 66
CK2#
DQ31 68
CKE0
DQ32 127
CKE1
DQ33 129
CAS#
DQ34 135
RAS#
DQ35 139
WE#
DQ36 128
S0#
DQ37 130
S1#
DQ38 136
SA0
DQ39 140
SA1
DQ40 141
SA2
DQ41 145
SCL
DQ42 151
SDA
DQ43 153
RESET(DU)
DQ44 142
DQ45 146
DM0
DQ46 152
DM1
DQ47 154
DM2
DQ48 163
DM3
DQ49 165
DM4
DQ50 171
DM5
DQ51 175
DM6
DQ52 164
DM7
DQ53 166
DM8
DQ54 172
DQ55 176
DQS0
DQ56 177
DQS1
DQ57 181
DQS2
DQ58 187
DQS3
DQ59 189
DQS4
DQ60 178
DQS5
DQ61 182
DQS6
DQ62 188
DQS7
DQ63 190
M_DATA_R_0
M_DATA_R_1
M_DATA_R_2
M_DATA_R_3
M_DATA_R_4
M_DATA_R_5
M_DATA_R_6
M_DATA_R_7
M_DATA_R_8
M_DATA_R_9
M_DATA_R_10
M_DATA_R_11
M_DATA_R_12
M_DATA_R_13
M_DATA_R_14
M_DATA_R_15
M_DATA_R_16
M_DATA_R_17
M_DATA_R_18
M_DATA_R_19
M_DATA_R_20
M_DATA_R_21
M_DATA_R_22
M_DATA_R_23
M_DATA_R_24
M_DATA_R_25
M_DATA_R_26
M_DATA_R_27
M_DATA_R_28
M_DATA_R_29
M_DATA_R_30
M_DATA_R_31
M_DATA_R_32
M_DATA_R_33
M_DATA_R_34
M_DATA_R_35
M_DATA_R_36
M_DATA_R_37
M_DATA_R_38
M_DATA_R_39
M_DATA_R_40
M_DATA_R_41
M_DATA_R_42
M_DATA_R_43
M_DATA_R_44
M_DATA_R_45
M_DATA_R_46
M_DATA_R_47
M_DATA_R_48
M_DATA_R_49
M_DATA_R_50
M_DATA_R_51
M_DATA_R_52
M_DATA_R_53
M_DATA_R_54
M_DATA_R_55
M_DATA_R_56
M_DATA_R_57
M_DATA_R_58
M_DATA_R_59
M_DATA_R_60
M_DATA_R_61
M_DATA_R_62
M_DATA_R_63
+V3.3S_SPD
C482
0.1UF
R509 0
40 SM_VREF_DIMM
CON200_DDR-SODIMM
VSS1 3
VDD1
VSS2 15
VDD2
VSS3 27
VDD3
VSS4 39
VDD4
VSS5 51
VDD5
VSS6 63
VDD6
VSS7 75
VDD7
VSS8 87
VDD8
VSS9 103
VDD9
VSS10 125
VDD10
VSS11 137
VDD11
VSS12 149
VDD12
VSS13 159
VDD13
VSS14 161
VDD14
VSS15 173
VDD15
VSS16 185
VDD16
VSS17 4
VDD17
VSS18 16
VDD18
VSS19 28
VDD19
VSS20 38
VDD20
VSS21 40
VDD21
VSS22 52
VDD22
VSS23 64
VDD23
VSS24 76
VDD24
VSS25 88
VDD25
VSS26 90
VDD26
VSS27 104
VDD27
VSS28 126
VDD28
VSS29 138
VDD29
VSS30 150
VDD30
VSS31 162
VDD31
VSS32 174
VDD32
VSS33 186
VDD33
199
197
1
2
VDDID
VDDSPD
VREF1
VREF2
13,40 +V2.5_DDR
DQS8
SO DIMM 1
9
21
33
45
57
69
81
93
113
131
143
155
157
167
179
191
10
22
34
36
46
58
70
82
92
94
114
132
144
156
168
180
192
+V3.3S_SPD
SM_VREF_DIMM_D
J64B
J72B
DU1
DU2
DU3
DU4
GND0
GND1
42
42
42
42
RSVD4
RSVD5
RSVD6
RSVD7
RSVD4
RSVD5
RSVD6
RSVD7
Title
Size
A
Date:
A
B
C
85
123
124
200
201
202
3
CON200_DDR-SODIMM_REV
VSS1 3
VSS2 15
VSS3 27
VSS4 39
VSS5 51
VSS6 63
VSS7 75
VSS8 87
VSS9 103
VSS10 125
VSS11 137
VSS12 149
VSS13 159
VSS14 161
VSS15 173
VSS16 185
VSS17 4
VSS18 16
VSS19 28
VSS20 38
VSS21 40
VSS22 52
VSS23 64
VSS24 76
VSS25 88
VSS26 90
VSS27 104
VSS28 126
VSS29 138
VSS30 150
VSS31 162
VSS32 174
VSS33 186
9
21
33
45
57
69
81
93
113
131
143
155
157
167
179
191
10
22
34
36
46
58
70
82
92
94
114
132
144
156
168
180
192
VDD1
VDD2
VDD3
VDD4
VDD5
VDD6
VDD7
VDD8
VDD9
VDD10
VDD11
VDD12
VDD13
VDD14
VDD15
VDD16
VDD17
VDD18
VDD19
VDD20
VDD21
VDD22
VDD23
VDD24
VDD25
VDD26
VDD27
VDD28
VDD29
VDD30
VDD31
VDD32
VDD33
199
197
1
2
VDDID
VDDSPD
VREF1
VREF2
DU1
DU2
DU3
DU4
GND0
GND1
C526
0.1UF
1
4
85
123
124
200
201
202
RSVD4
RSVD6
RSVD7
DDR SO-DIMM
Project:
Document Number
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
10
of
E
47
2
1
A
B
C
D
E
M_DATA_R_[63:0] 10,12
M_DATA4
M_DATA5
M_DATA6
M_DATA7
M_DATA8
M_DATA9
M_DATA10
M_DATA11
M_DATA12
M_DATA13
M_DATA14
2
8 RP45A 1 10
M_DATA_R_32
3 RP37C 6 10
M_DATA_R_1
M_DATA33
7 RP45B 2 10
M_DATA_R_33
1 RP37A 8 10
M_DATA_R_2
M_DATA34
5 RP45D 4 10
M_DATA_R_34
4 RP44D 5 10
M_DATA_R_3
M_DATA35
4 RP40D 5 10
M_DATA_R_35
4 RP27D 5 10
M_DATA_R_4
4 RP29D 5 10
M_DATA_R_36
M_DATA1
M_DATA3
3
M_DATA32
4 RP37D 5 10
M_DATA2
4
M_DATA_R_0
M_DATA0
3 RP27C 6 10
M_DATA_R_5
M_DATA36
M_DATA37
3 RP29C 6 10
M_DATA_R_6
M_DATA38
2 RP29B 7 10
M_DATA_R_38
1 RP27A 8 10
M_DATA_R_7
M_DATA39
1 RP29A 8 10
M_DATA_R_39
2 RP44B 7 10
4 RP38D 5 10
3 RP38C 6 10
4 RP33D 5 10
3 RP33C 6 10
2 RP33B 7 10
M_DATA_R_8
M_DATA_R_9
M_DATA_R_10
M_DATA_R_11
M_DATA_R_12
M_DATA_R_13
M_DATA_R_14
M_DATA40
M_DATA41
M_DATA42
M_DATA43
M_DATA44
M_DATA45
M_DATA46
3 RP40C 6 10
2 RP40B 7 10
4 RP41D 5 10
3 RP41C 6 10
4 RP30D 5 10
3 RP30C 6 10
2 RP30B 7 10
M_A12
M_A11
M_A10
M_A9
10
M_A_FR_12
R448
10
M_A_FR_11
R472
10
M_A_FR_10
R460
10
M_A_FR_9
R504
M_A8
R447
10
M_A_FR_8
M_A7
R503
10
M_A_FR_7
M_A6
R446
10
M_A_FR_6
M_A5
R470
10
M_A_FR_5
M_A4
R461
10
M_A_FR_4
M_A3
R502
10
M_A_FR_3
M_A2
R445
10
M_A_FR_2
M_A1
R473
10
M_A_FR_1
M_A0
R462
10
M_A_FR_0
M_DATA_R_41
M_DATA_R_42
M_DATA_R_43
M_DATA_R_44
M_DATA_R_45
M_DATA_R_46
1 RP33A 8 10
M_DATA_R_15
M_DATA47
1 RP30A 8 10
M_DATA_R_47
M_DATA16
2 RP38B 7 10
M_DATA_R_16
M_DATA48
2 RP41B 7 10
M_DATA_R_48
M_DATA17 1 RP38A 8 10
M_DATA_R_17
M_DATA49
1 RP41A 8 10
M_DATA_R_49
4 RP39D 5 10
M_DATA_R_18
M_DATA50
3 RP42C 6 10
M_DATA_R_50
M_CB_R4
1 RP36A 8 10
M_CB4
M_DATA19 3 RP39C 6 10
M_DATA_R_19
M_DATA51
2 RP42B 7 10
M_DATA_R_51
M_CB_R6
3 RP36C 6 10
M_CB6
M_DATA52
10,12 M_CB_R[7:0]
M_DATA20
4 RP34D 5 10
M_DATA_R_20
4 RP31D 5 10
M_DATA_R_52
M_CB_R5
2 RP36B 7 10
M_CB5
M_DATA21
3 RP34C 6 10
M_DATA_R_21
M_DATA53
3 RP31C 6 10
M_DATA_R_53
M_CB_R7
4 RP36D 5 10
M_CB7
M_DATA22 2 RP34B 7 10
M_DATA_R_22
M_DATA54
2 RP31B 7 10
M_DATA_R_54
M_CB_R3
4 RP46D 5 10
M_CB3
M_DATA23
1 RP34A 8 10
M_DATA_R_23
M_DATA55
1 RP31A 8 10
M_DATA_R_55
M_CB_R2
3 RP46C 6 10
M_CB2
M_DATA24
2 RP39B 7 10
M_DATA_R_24
M_DATA56
1 RP42A 8 10
M_DATA_R_56
M_CB_R1
1 RP46A 8 10
M_CB1
M_DATA25 1 RP39A 8 10
M_DATA_R_25
M_DATA57
4 RP43D 5 10
M_DATA_R_57
M_CB_R0
4 RP47D 5 10
M_CB0
M_DATA_R_26
M_DATA58
2 RP43B 7 10
M_DATA_R_58
M_DATA59
1 RP43A 8 10
M_DATA_R_59
4 RP32D 5 10
3
M_CB[7:0] 6
M_DATA26
7 RP47B 2 10
M_DATA27
6 RP47C 3 10
M_DATA_R_27
M_DATA28
4 RP28D 5 10
M_DATA_R_28
M_DATA_R_60
M_DQS_R8
2 RP46B 7 10
M_DQS8
M_DATA29
3 RP28C 6 10
M_DATA_R_29
M_DATA61
3 RP32C 6 10
M_DATA_R_61
M_DQS_R7
6 RP43C 3 10
M_DQS7
M_DATA30
2 RP28B 7 10
M_DATA_R_30
M_DATA62
2 RP32B 7 10
M_DATA_R_62
M_DQS_R6
5 RP42D 4 10
M_DQS6
M_DATA31 1 RP28A 8 10
M_DATA_R_31
M_DATA63
1 RP32A 8 10
M_DATA_R_63
M_DQS_R5
8 RP40A 1 10
M_DQS5
M_DQS_R4
3 RP45C 6 10
M_DQS4
M_DQS_R3
1 RP47A 8 10
M_DQS3
M_DATA60
4
M_DATA_R_40
M_DATA15
M_DATA18
M_A_FR_[12:0] 10
M_DATA_R_37
2 RP27B 7 10
3 RP44C 6 10
6,10,12 M_A[12:0]
10,12 M_DQS_R[8:0]
M_DQS_R2
6 M_DATA[63:0]
R234
10
2
M_DQS2
M_DQS_R1
8 RP44A 1 10
M_DQS1
M_DQS_R0
7 RP37B 2 10
M_DQS0
M_DQS[8:0] 6
6,10,12 M_BS0#
6,10,12 M_BS1#
6,10,12 M_CAS#
1
6,10,12 M_RAS#
6,10,12 M_WE#
Title
R501
10
R463
10
R443
10
R444
10
R471
10
M_BS0_FR# 10
M_BS1_FR# 10
M_CAS_FR# 10
1
M_RAS_FR# 10
M_WE_FR# 10
DDR SERIES TERMINATION
Size Project:
Custom
855PM Platform
Date:
Monday, February 24, 2003
A
B
C
D
Document Number
Sheet
Rev
of
11
E
47
E
of
8
3
7
4
6
8
1
6
2
5
3
1
4
RP71D
56
RP71A
56
RP75C
56
RP60D
56
RP75B
56
RP60C
56
RP68A
56
5
7
RP60B 7
56
RP68B 2
56
8
8
6
8
2
3
8
7
6
4
1
8
3
5
8
7
6
5
5
6
7
8
5
7
6
5
8
6
7
8
8
7
6
5
5
6
2
1
1
3
1
7
R286
56
R291
56
R290
56
R289
56
RP71C
56
RP71B
56
RP59A
56
RP58C
56
RP77A
56
RP58A
56
6
1
2
3
5
8
1
6
4
1
2
3
4
4
3
2
1
4
2
3
4
1
3
2
1
1
2
3
4
4
3
1
2
3
4
4
3
2
1
7
5
4
6
7
5
6
5
5
3
2
4
3
4
2
8
7
6
5
5
6
7
8
4
3
2
1
1
2
3
4
5
6
7
8
8
7
6
5
5
6
7
8
8
7
RP74A
56
RP74B
56
RP74C
56
RP74D
56
RP67D
56
RP67C
56
RP67B
56
RP67A
56
8
7
6
5
5
6
7
8
RP58D 4
56
RP58B 2
56
R282
56
R293
56
R288
56
R285
56
R292
56
R284
56
R283
56
RP77B
56
RP59D
56
RP77C
56
RP77D
56
RP59B
56
RP59C
56
RP75D
56
7
1
2
3
4
4
3
2
1
5
6
7
8
8
7
6
5
4
3
2
1
1
2
3
4
4
3
2
1
1
6
M_CB_R1
12
M_CB_R0
2
6,10,42 M_CKE0_R
6,10,42 M_CKE1_R
M_CB_R2
7
D
M_CB_R3
Sheet
M_CB_R4
855PM Platform
Monday, February 24, 2003
M_CB_R6
Project:
M_CB_R5
M_DQS_R6
M_DQS_R5
D
M_CB_R7
2
M_DQS_R1
5
C
M_DQS_R0
M_DQS_R8
M_DQS_R7
Size
A
Date:
M_DQS_R3
3
M_A[12:0]
M_DQS_R2
M_A7
M_A8
M_A9
M_A10
M_A11
M_A12
Title
M_DQS_R4
M_A0
RP66D
56
RP66C
56
RP66B
56
RP66A
56
RP73A
56
RP73B
56
RP73C
56
RP73D
56
RP65D
56
RP65C
56
RP65B
56
RP65A
56
RP72A
56
RP72B
56
RP72C
56
RP72D
56
RP76D
56
RP76C
56
RP76B
56
RP76A
56
RP57A
56
RP57B
56
RP57C
56
RP57D
56
RP70A
56
RP70B
56
RP70C
56
RP70D
56
RP64D
56
RP64C
56
RP64B
56
RP64A
56
4
M_A1
M_A2
M_A3
4
M_DATA_R_[63:0]
M_A4
8
M_A6
M_DATA_R_32
M_DATA_R_33
M_DATA_R_34
M_DATA_R_35
M_DATA_R_36
C
M_A5
RP63A
56
RP63B
56
RP63C
56
RP63D
56
RP81D
56
RP81C
56
RP81B
56
RP81A
56
RP62A
56
RP62B
56
RP62C
56
RP80A
56
RP80D
56
RP80C
56
RP80B
56
RP62D
56
RP61A
56
RP61B
56
RP61C
56
RP61D
56
RP79D
56
RP79C
56
RP79B
56
RP79A
56
RP78D
56
RP68C
56
RP78A
56
RP75A
56
RP68D
56
RP78C
56
RP78B
56
RP60A
56
B
M_DATA_R_0
M_DATA_R_1
M_DATA_R_2
M_DATA_R_3
M_DATA_R_4
M_DATA_R_37
M_DATA_R_38
M_DATA_R_39
M_DATA_R_40
M_DATA_R_41
M_DATA_R_42
M_DATA_R_43
M_DATA_R_44
Place Test Points for
all CKE and CS
signals near via on
top side as close to
RPACK as possible.
M_DATA_R_5
M_DATA_R_6
M_DATA_R_7
M_DATA_R_8
M_DATA_R_9
M_DATA_R_10
M_DATA_R_11
M_DATA_R_45
M_DATA_R_46
M_DATA_R_47
M_DATA_R_48
M_DATA_R_49
M_DATA_R_50
M_DATA_R_51
M_DATA_R_52
M_DATA_R_53
M_DATA_R_54
M_DATA_R_55
M_DATA_R_56
B
M_DATA_R_12
M_DATA_R_13
M_DATA_R_14
M_DATA_R_15
M_DATA_R_16
M_DATA_R_17
M_DATA_R_18
M_DATA_R_19
M_DATA_R_20
M_DATA_R_21
M_DATA_R_22
M_DATA_R_23
M_DATA_R_57
M_DATA_R_58
M_DATA_R_59
M_DATA_R_60
M_DATA_R_61
M_DATA_R_62
M_DATA_R_63
A
M_DATA_R_24
M_DATA_R_25
M_DATA_R_26
M_DATA_R_27
M_DATA_R_28
M_DATA_R_29
M_DATA_R_30
M_DATA_R_31
3
1
A
E
6,13,40,42 +V1.25S
6,10,42 M_CS0_R#
6,10,42 M_CS1_R#
M_CB_R[7:0] 10,11
4
M_DQS_R[8:0]
3
10,11 M_DATA_R_[63:0]
10,11 M_DQS_R[8:0]
6,10,11 M_A[12:0]
2
6,10 M_CS2_R#
6,10 M_CS3_R#
2
6,10 M_CKE3_R
6,10 M_CKE2_R
6,10,11 M_BS0#
6,10,11 M_BS1#
6,10,11 M_RAS#
6,10,11 M_WE#
6,10,11 M_CAS#
1
1
DDR Parallel Termination
Document Number
Rev
47
A
B
C
D
E
+V2.5_DDR 10,40
40 +V2.5
R191
0.01_1%
4
C515
0.1UF
C516
0.1UF
C530
0.1UF
C532
0.1UF
C513
0.1UF
C531
0.1UF
C502
0.1UF
C533
0.1UF
C514
0.1UF
C486
0.1UF
C501
0.1UF
C262
150uF
C279
150uF
C285
150uF
C264
150uF
C484
0.1UF
C487
0.1UF
C500
0.1UF
C499
0.1UF
C485
0.1UF
C483
0.1UF
4
Layout note: Place capacitors between and near DDR connector if possible.
3
3
Layout note: Place one cap close to every 2 pullup resistors terminated
to +V1.25.
6,12,40,42 +V1.25S
2
1
C577
0.1UF
C575
0.1UF
C578
0.1UF
C560
0.1UF
C548
0.1UF
C568
0.1UF
C566
0.1UF
C562
0.1UF
C541
0.1UF
C582
0.1UF
C555
0.1UF
C556
0.1UF
C580
0.1UF
C543
0.1UF
C544
0.1UF
C539
0.1UF
C565
0.1UF
C567
0.1UF
C587
0.1UF
C592
0.1UF
C552
0.1UF
C586
0.1UF
C590
0.1UF
C549
0.1UF
C572
0.1UF
C571
0.1UF
C579
0.1UF
C542
0.1UF
C554
0.1UF
C553
0.1UF
C574
0.1UF
C547
0.1UF
C584
0.1UF
C570
0.1UF
C594
0.1UF
C588
0.1UF
C573
0.1UF
C591
0.1UF
C589
0.1UF
C585
0.1UF
C559
0.1UF
C576
0.1UF
C550
0.1UF
C564
0.1UF
C540
0.1UF
C581
0.1UF
C551
0.1UF
C558
0.1UF
C563
0.1UF
C569
0.1UF
C583
0.1UF
C561
0.1UF
C593
0.1UF
C557
0.1UF
2
1
Title
Size
A
Date:
A
B
C
DDR Decoupling
Project:
Document Number
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
13
of
E
47
A
B
C
9,18,20,24,34,41 +V12S
D
+V3.3S
3
SMB_DATA 10,15,18,21
CK408_DATA_D
+V3.3S_CLKRC
BSS138
1
2
1
R147
1K
SMB_CLK 10,15,18,21
CK408_CLK_D
14.318MHZ
FB20
300ohm@100MHz
1
2
C235
NO_STUFF_10pF
C234
NO_STUFF_10pF
1
8
14
19
32
37
46
50
C223
0.1UF
10UF
3
VDD5_48Mhz
R416
2
XTAL_IN
XTAL_OUT
3
XTAL_OUT
CK408_SEL2
1K
R156
1K
40
CK408_SEL1
55
CK408_SEL0
54
CLK_PWRDWN#
R155
NO_STUFF_0
+V3.3S_CLKRC
25
34
16,34 PM_STPPCI#
53
16,34,36,38 PM_STPCPU#
36 VR_PWRGD_CK408#
3
CR16
J50
1
BSEL0_Q
3
NO_STUFF_BAR43
MULT0
NO_STUFF_BAR43
BSEL1_Q
10K
1
1
R415
2
C465
NO_STUFF_0.1UF
NO_STUFF_0.1UF
VDD0
VDD1
VDD2
VDD3
VDD4
VDD5
VDD6
VDD7
XTAL_IN
R157
1K
CR17
1UF
C227 C459
0.1UF
0.1UF
C463
0.1UF
C453
0.1UF
42 CLK_PLD
C456
NO_STUFF_10pF
+V3SA_CLK
SEL2
PWRDWN#
PCI_STOP#
CPU_STOP#
C469
C470
0.1UF
10UF
0.1UF
0.1UF
VDDA
26
VSSA
27
CPU2
45
CPU2
R165
33
CPU2#
44
CPU2#
R166
33
R163
33
R164
33
49
48
CPU1#
CPU0
52
CPU0
R161
NO_STUFF_33
CPU0#
51
CPU0#
R162
NO_STUFF_33
66INPUT
24
TP_66INPUT
66BUF2
23
66BUF2
66BUF1
22
66BUF1
66BUF0
21
66BUF0
PCIF2
7
PCIF2
TP_PCIF1
VTT_PWRGD#
PCIF1
6
43
MULT0
PCIF0
5
PCIF0
PCI6
SDATA
PCI6
30
SCLOCK
PCI5
17
PCI5
PCI4
3V66_0
33
3V66_0
PCI4
16
TP_3V66_1
35
3V66_1/VCH
PCI3
13
PCI3
42
IREF
PCI2
12
PCI2
PCI1
11
PCI1
41
4
9
15
20
31
36
47
VSSIREF
VSS0
VSS1
VSS6
VSS2
VSS3
VSS4
VSS5
PCI0
10
PCI0
USB
39
USB
DOT
38
TP_DOT
REF
56
CLK_REF0
7
16,22,29,34,40,41 PM_SLP_S3#
2
3 RP23C
33
2 RP25B
33
3 RP25C
33
4 RP25D
33
1 RP24A
33
2 RP24B
33
3 RP24C
33
4 RP24D
33
1 RP23A
33
R167
33
6
A
33
R148
33
CLK_ICH66 8,15
5
CLK_ICHPCI 15
7
7
CLK_PCI_PORT80 30
CLK_PCI_SLOT3 20
6
CLK_PCI_SLOT2 19
5
CLK_PCI_SLOT1 19
8
CLK_DOCKPCI 21
7
CLK_FWHPCI 28
6
CLK_SIOPCI 31
5
CLK_SMCPCI 29
8
CLK_LPCPCI 34
CLK_ICH48 16
R188
33
R173
33
CLK_LPC14 34
CLK_SIO14 31
33
CLK_ICH14 16
CLK_ITP_CPU 3
CLK_ITP 5
CLK_ITP_CPU# 3
CLK_ITP# 5
CLK_AGP_SLOT 9
C254
NO_STUFF_10pF
C253
NO_STUFF_10pF
C260
NO_STUFF_10pF
C252
NO_STUFF_10pF
C251
NO_STUFF_10pF
C259
NO_STUFF_10pF
C266
NO_STUFF_10pF
C258
NO_STUFF_10pF
C257
NO_STUFF_10pF
C256
NO_STUFF_10pF
C265
NO_STUFF_10pF
C255
NO_STUFF_10pF
C267
NO_STUFF_10pF
C219
NO_STUFF_10pF
C246
NO_STUFF_10pF
C238
NO_STUFF_10pF
C243
NO_STUFF_10pF
CLK_PWRDWN#
4
Title
Size
A
Date:
3
B
R140
U33
74AHC1G08
0.7 VOLTS
3
CLK_MCH66 6
6
+V3.3S
5
CK408 CLOCK SWING CONFIG
1
49.9_1%
49.9_1%
CLK_MCH_BCLK# 7
R181
16,24,41 PM_SLP_S1#
R137
CLK_MCH_BCLK 7
2 RP26B
33
3 RP26C
33
4 RP26D
33
2 RP23B
33
CK-408
5,9,10,15,17,18,20,23,28,30,31,32,33,36,37,38,41,42
R138 R136
CLK_CPU_BCLK# 3
CPU1
28
No Stuff
R142
CLK_CPU_BCLK 3
CPU1#
SMB_CK408_CLK
CK_IREF
2
49.9_1%
49.9_1%
18
R420
33
4
CLK_ITP_CPU#
CLK_ITP_CPU
CLK_ITP#
CLK_ITP
300ohm@100MHz
CPU1
SEL1
SEL0
1
C247
29
Measurement Point
MULTIREF
(R419)
1
475 1%
0.01_1%
0.1UF
C468
SMB_CK408_DATA
R419
475_1%
2
1
C460
0.1UF
FB21
U32
+V3.3S_CLKRC
R168
NO_STUFF_330
10UF
C461
CK-408
SMB_CK408_CLK
+V3.3S_CLKRC
C452
No stuff; caps
are internal to
CK-408.
C462
BSS138
2
R179
NO_STUFF_0
Place 0ohm near
crystal.
Y3
C237
Q29
1
Place crystal within 500
mils of CK_408
R182
FB19
1
2
300ohm@100MHz
C464
+VDD3S_CLK
2
NO_STUFF_SMA CON
SMB_CK408_DATA
3
3
4
XTAL_IN_D
5
2
R152 10K
SMB_CK408_CLK
1
J48
4
+V3.3S
R153 10K
SMB_CK408_DATA
Q30
R146
1K
E
5,9,10,15,17,18,20,23,28,30,31,32,33,36,37,38,41,42
5,9,10,15,17,18,20,23,28,30,31,32,33,36,37,38,41,42
C
CK-408
Document Number
Project:
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
of
14
E
47
2
1
B
C
D
E
5,9,10,14,17,18,20,23,28,30,31,32,33,36,37,38,41,42
PCI_C/BE0#
PCI_C/BE1#
PCI_C/BE2#
PCI_C/BE3#
TP_GNT0#
PCI_GNT1#
PCI_GNT2#
PCI_GNT3#
PCI_GNT4#
C1
E6
A7
B7
D6
PCI_GNT0#
PCI_GNT1#
PCI_GNT2#
PCI_GNT3#
PCI_GNT4#
PCI_REQ0#
PCI_REQ1#
PCI_REQ2#
PCI_REQ3#
PCI_REQ4#
B1
A2
B3
C7
B6
PCI_REQ0#
PCI_REQ1#
PCI_REQ2#
PCI_REQ3#
PCI_REQ4#
2
14
18,19,20,21
18,19,20,21
19
21
16,19
21
18,19,20,21
19,20,21
18,19,20
18,19,20,21
CLK_ICHPCI
PCI_DEVSEL#
PCI_FRAME#
PCI_REQA#
PCI_REQB#
PCI_GNTA#
PCI_GNTB#
PCI_IRDY#
PCI_PAR
PCI_PERR#
PCI_LOCK#
P5
M3
F1
B5
A6
E8
C5
L5
G1
L4
M2
W2
U5
K5
F3
F2
PCI_CLK
PCI_DEVSEL#
PCI_FRAME#
PCI_GPIO0/REQA#
PCI_GPIO1/REQB_L/REQ5#
PCI_GPIO16/GNTA#
PCI_GPIO17/GNTB_L/GNT5#
PCI_IRDY#
PCI_PAR
PCI_PERR#
PCI_LOCK#
PCI_PME#
PCI_RST#
PCI_SERR#
PCI_STOP#
PCI_TRDY#
18,19,20,21 PCI_SERR#
18,19,20,21 PCI_STOP#
18,19,20,21 PCI_TRDY#
CPU I/F
Hub
I/F
Interrupt
I/F
18
18,19
18,19
18,20
18,21
L19
L20
M19
M21
P19
R19
T20
R20
P23
L22
N22
K21
T21
HUB_PSTRB#
HUB_PSTRB
HUB_RCOMP
HUB_VREF
HUB_VSWING
N20
P21
R23
M23
R22
INT_APICCLK
INT_APICD0
INT_APICD1
INT_PIRQA#
INT_PIRQB#
INT_PIRQC#
INT_PIRQD#
INT_PIRQE#/GPIO2
INT_PIRQF#/GPIO3
INT_PIRQG#/GPIO4
INT_PIRQH#/GPIO5
INT_IRQ14
INT_IRQ15
INT_SERIRQ
EEPROM
I/F
19
19
20
21
PCI
I/F
HUB_PD0
HUB_PD1
HUB_PD2
HUB_PD3
HUB_PD4
HUB_PD5
HUB_PD6
HUB_PD7
HUB_PD8
HUB_PD9
HUB_PD10
HUB_PD11
HUB_CLK
CPU_A20M#
CPU_DPSLP#
CPU_FERR#
CPU_IGNNE#
CPU_INIT#
CPU_INTR
CPU_NMI
CPU_SLP#
CPU_SMI#
CPU_STPCLK#
R520
R246
1.5K
56
R521
R299
R518
R513
0
0
56
0
R517
R298
0
0
R510
R296
R512
H_INIT#_DQ
J2
K4
M4
N4
PART A
Y22
AB23
U23
AA21
W21
V22
AB22
V21
Y23
U22
U21
W23
V23
+VCCP
SM_INTRUDER# 18,34
SMLINK0 18,19,20
SMLINK1 18,19,20
SMB_CLK 10,14,18,21
SMB_DATA 10,14,18,21
SMB_ALERT# 18,34
H_A20GATE 33
H_A20M# 3
H_DPSLP# 3,6,34
H_FERR# 3
H_IGNNE# 3
H_INTR 3,34
H_NMI 3,34
H_PWRGD 3,34
H_RCIN# 29,34
H_CPUSLP# 3,34
H_SMI# 3,34
H_STPCLK# 3,34
0
0
0
H_INIT#_D
R300
330
R249
330
6
2
3
FWH_INIT# 28
CR11B
3904
4
1
CR11A
3904
5
4
R301
0
H_INIT# 3,34
17 +V1.8S_ICHHUB
HUB_PD[10:0] 6,8
HUB_PD0
HUB_PD1
HUB_PD2
HUB_PD3
HUB_PD4
HUB_PD5
HUB_PD6
HUB_PD7
HUB_PD8
HUB_PD9
HUB_PD10
J61
2
1
PLACE RCOMP resistor
within 0.5" of ICH pad using
a thick trace
R276
36.5
1%
NO_STUFF_CON3_HDR
2
J63
RCOMP R should be 2/3
board impedance
1HUB_VREF_ICH_D
No Stuff
C518
R464
TP_HUB_PD11 34
CLK_ICH66 8,14
0
0.01UF
HUB_PSTRB# 6,8
HUB_PSTRB 6,8
HUB_RCOMP_ICH
HUB_VREF_ICH
HUB_VSWING_ICH
R465
150_1%
3
R490
150_1%
C506
0.01UF
3
10 mil trace, 7 mil space
+V1.8S_ICHHUB 17
INT_APICCLK
J19
INT_APICD0
H19
INT_APICD1
K20
D5
C2
B4
A3
R198
0
C8 INT_PIRQE#_D
R197
0
D7 INT_PIRQF#_D
INT_PIRQG#_D
R160
0
C3
R219
0
C4 INT_PIRQH#_D
AC13
INT_IRQ14 18,23,34
AA19
INT_IRQ15 18,23,34
J22
INT_SERIRQ 19,20,21,29,31,34
HUB INTERFACE VSWING VOLTAGE
INT_PIRQA#
INT_PIRQB#
INT_PIRQC#
INT_PIRQD#
INT_PIRQE#
INT_PIRQF#
INT_PIRQG#
INT_PIRQH#
9,18,19,20,21
9,18,19,20,21
18,19,20,21
(1/2)
18,19,20,21
18,20
18,20
18,20
C300
18,20,34
R267
150_1%
J60
No Stuff
D10
D11
A8
C12
EEP_CS
EEP_SK
LAN_RXD0
LAN_RXD1
LAN_RXD2
LAN_TXD0
LAN_TXD1
LAN_TXD2
LAN_JCLK
LAN_RSTSYNC
LAN_RST#
A10
A9
A11
B10
C10
A12
C11
B11
Y5
LAN_RXD0 27
LAN_RXD1 27
EEPROM for ICH4-M LAN
LAN_RXD2 27
LAN_TXD0 27
LAN_TXD1 27
LAN_EEP_DOUT 16
LAN_TXD2 27
LAN_JCLK 27
LAN_RST 27
PM_LANPWROK 27,29
EEP_DIN
range for R264, R267: 100 - 150 ohm
U35
EEP_CS
EEP_DIN
EEP_DOUT
EEP_SHCLK
1
2
3
4
1.8V
0.01UF
17 +V3.3_ICHLAN
HUB INTERFACE LAYOUT:
Route signals with 4/8 trace/space routing. Signals
must match +/- 0.1" of HUB_PSTRB/PSTRB#
R264
150_1%
1
PCI_C/BE0#
PCI_C/BE1#
PCI_C/BE2#
PCI_C/BE3#
3
ICH4-M
CPU_A20GATE
CPU_A20M#
CPU_DPSLP#
CPU_FERR#
CPU_IGNNE#
CPU_INIT#
CPU_INTR
CPU_NMI
CPU_PWRGOOD
CPU_RCIN#
CPU_SLP#
CPU_SMI#
CPU_STPCLK#
W6
AC3
AB1
AC4
AB4
AA5
CS VCC
SK
DC
DI ORG
DO GND
8
7
6
5
2
2
PCI_AD0
PCI_AD1
PCI_AD2
PCI_AD3
PCI_AD4
PCI_AD5
PCI_AD6
PCI_AD7
PCI_AD8
PCI_AD9
PCI_AD10
PCI_AD11
PCI_AD12
PCI_AD13
PCI_AD14
PCI_AD15
PCI_AD16
PCI_AD17
PCI_AD18
PCI_AD19
PCI_AD20
PCI_AD21
PCI_AD22
PCI_AD23
PCI_AD24
PCI_AD25
PCI_AD26
PCI_AD27
PCI_AD28
PCI_AD29
PCI_AD30
PCI_AD31
4
19,20,21
19,20,21
19,20,21
19,20,21
3,4,5,7,16,17,37,39,42
SM_INTRUDER#
SMLINK0
SMLINK1
SMB_CLK
SMB_DATA
SMB_ALERT#/GPIO11
H5
J3
H3
K1
G5
J4
H4
J5
K2
G2
L1
G4
L2
H2
L3
F5
F4
N1
E5
N2
E3
N3
E4
M5
E2
P1
E1
P2
D3
R1
D2
P4
LAN
I/F
PCI_AD0
PCI_AD1
PCI_AD2
PCI_AD3
PCI_AD4
PCI_AD5
PCI_AD6
PCI_AD7
PCI_AD8
PCI_AD9
PCI_AD10
PCI_AD11
PCI_AD12
PCI_AD13
PCI_AD14
PCI_AD15
PCI_AD16
PCI_AD17
PCI_AD18
PCI_AD19
PCI_AD20
PCI_AD21
PCI_AD22
PCI_AD23
PCI_AD24
PCI_AD25
PCI_AD26
PCI_AD27
PCI_AD28
PCI_AD29
PCI_AD30
PCI_AD31
System
Management
I/F
U42A
19,20,21 PCI_AD[31:0]
+V3.3S
range for R465, R490: 100 - 150 Ohm
A
TP_EEPROM0
TP_EEPROM1
ICH4-M
ICH_PME#
9,19,20,34 PCI_PME#
R297
INT_APICCLK
INT_APICD0
INT_APICD1
0
6,23,28,34,42 PCI_RST#
+V3.3
1
7,9,17,20,24,27,29,32,34,36,40,41
R483
10K
R498
10K
R494
0
1
5
2
9,19,20,21,29,30,31,34
BUF_PCI_RST#
4
U41
BUFFER
A
Title
1
OE
Size
A
Date:
3
B
C
ICH4-M (1 of 3)
Project:
Document Number
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
15
of
E
47
ICH4M Strapping Options
Board Default
R394
Safe Mode Boot
NO STUFF
R395
A16 swap override
NO STUFF
R396
Reserved
NO STUFF
4
Optional Override
9 AGP_BUSY#
41 PM_SYSRST#
29,33,34 PM_BATLOW#
9,34 PM_C3_STAT#
STUFF for safe mode
18,29,31,34 PM_CLKRUN#
34,36,38
PM_DPRSLPVR
STUFF for A16 swap override
29,34 PM_PWRBTN#
18,22,29,34,36
PM_PWROK
STUFF
18,32,34 PM_RI#
18,29,34 PM_RSMRST#
R295
14,24,41 PM_SLP_S1#
R314
14,22,29,34,40,41 PM_SLP_S3#
R280
29,34,41 PM_SLP_S4#
R328
34,41 PM_SLP_S5#
14,34,36,38 PM_STPCPU#
14,34 PM_STPPCI#
34 PM_SUS_CLK
3,4,5,7,15,17,37,39,42 +VCCP
9,29,31,34 PM_SUS_STAT#
5,18,29,34 PM_THRM#
34 PM_GMUXSEL
R522
STUFF for No Reboot
R467
NO_STUFF_1K
AC_SPKR
R452
NO_STUFF_10K
AC_SDATAOUT
R453
NO_STUFF_1K
3
+V3.3ALWAYS
R451
5,9,17,18,19,20,24,25,26,29,33,34,36,41
RTC Circuitry
CR24
AC_BITCLK
AC_RST#
AC_SDATAIN0
AC_SDATAIN1
AC_SDATAIN2
AC_SDATAOUT
24 AC_SYNC
28,29,30,31,34 LPC_AD0
28,29,30,31,34 LPC_AD1
28,29,30,31,34 LPC_AD2
28,29,30,31,34 LPC_AD3
31,34 LPC_DRQ#0
34 LPC_DRQ#1
28,29,30,31,34 LPC_FRAME#
PCI_GNTA# 15,19
LAN_EEP_DOUT 15
17,18 +V_RTC
3
BAT54
C313
1
1
2
1UF
SHUNT J94
to Clear
CMOS
RTC_RST#
delay 18-25ms
25
25
26
25
26
26
25
25
26
25
26
26
25
25
26
25
26
26
RTC_RST#
R335
BAT54
180K
C324
V_RTCBATT_D
USB_OC0#
USB_OC1#
USB_OC2#
USB_OC3#
USB_OC4#
USB_OC5#
USB_RBIAS
J94
0.1UF
C316
0.047UF
BH1
Battery_Holder
Value for C310,
C597 depends
on Crystal
R523
10M
R228
34
22.6_1%
30
32
28,34
28,34
18
18
18
23,34
23,34
34
34
AGP_SUSPEND#
KSC_VPPEN#
SER_EN
FWH_WP#
FWH_TBL#
ICH_FAB_REV0
ICH_FAB_REV1
ICH_FAB_REV2
IDE_PATADET
IDE_SATADET
ICH_GPIO42
ICH_GPIO43
R496
R482
R508
R492
R491
R192
R193
R194
R334
R275
R485
R340
B8
C13
D13
A13
B13
D9
C9
T2
R4
T4
U2
U3
U4
T5
1K
1
V_RTCBATT
R326
1
Layout: Route
USB_RBIAS/RBIAS#
Differentially
2
2
3
ACSYNC_D
33
USB_PP0
USB_PP1
USB_PP2
USB_PP3
USB_PP4
USB_PP5
USB_PN0
USB_PN1
USB_PN2
USB_PN3
USB_PN4
USB_PN5
CR25
1
J21
Y20
V19
0
0
0
0
0
0
0
0
0
0
0
0
GPIO32
GPIO33
GPIO34
GPIO35
GPIO36
GPIO37
GPIO38
GPIO39
GPIO40
GPIO41
GPIO42
GPIO43
AC_BITCLK
AC_RST#
AC_SDATAIN0
AC_SDATAIN1
AC_SDATAIN2
AC_SDATAOUT
AC_SYNC
AC'97
I/F
LPC_AD0
LPC_AD1
LPC_AD2
LPC_AD3
LPC_DRQ0#
LPC_DRQ1#
LPC_FRAME#
LPC
I/F
C20
A21
C18
A19
C16
A17
D20
B21
D18
B19
D16
B17
USB_PP0
USB_PP1
USB_PP2
USB_PP3
USB_PP4
USB_PP5
USB_PN0#
USB_PN1#
USB_PN2#
USB_PN3#
USB_PN4#
USB_PN5#
B15
C14
A15
B14
A14
D14
USB_OC0#
USB_OC1#
USB_OC2#
USB_OC3#
USB_OC4#
USB_OC5#
A23
B23
USB_RBIAS
USB_RBIAS#
J20
G22
F20
G20
F21
H20
F23
H22
G23
H21
F22
E23
GPIO32
GPIO33
GPIO34
GPIO35
GPIO36
GPIO37
GPIO38
GPIO39
GPIO40
GPIO41
GPIO42
GPIO43
GPIO_7
GPIO_8
GPIO_12
GPIO_13
GPIO_25
GPIO_27
GPIO_28
USB
I/F
GPIO
R3
V4
V5
W3
V2
W1
W4
GPIO7
GPIO8
GPIO12
GPIO13
GPIO25
GPIO27
GPIO28
R330
R511
R515
R516
R524
R327
R332
0
0
0
0
0
0
0
ICH_GPIO7 34
SMC_EXTSMI# 29,31,33,34
SMC_RUNTIME_SCI# 29,33,34
SMC_WAKE_SCI# 29,33,34
AUDIO_PWRDN 24
ICH_MFG_MODE 34
ICH_GPIO28 34
Y13
AB14
AB21
AC22
IDE_PDCS1#
IDE_PDCS3#
IDE_SDCS1#
IDE_SDCS3#
IDE_PDA0
IDE_PDA1
IDE_PDA2
IDE_SDA0
IDE_SDA1
IDE_SDA2
AA13
AB13
W13
AA20
AC20
AC21
IDE_PDD0
IDE_PDD1
IDE_PDD2
IDE_PDD3
IDE_PDD4
IDE_PDD5
IDE_PDD6
IDE_PDD7
IDE_PDD8
IDE_PDD9
IDE_PDD10
IDE_PDD11
IDE_PDD12
IDE_PDD13
IDE_PDD14
IDE_PDD15
AB11
AC11
Y10
AA10
AA7
AB8
Y8
AA8
AB9
Y9
AC9
W9
AB10
W10
W11
Y11
IDE_PDD0
IDE_PDD1
IDE_PDD2
IDE_PDD3
IDE_PDD4
IDE_PDD5
IDE_PDD6
IDE_PDD7
IDE_PDD8
IDE_PDD9
IDE_PDD10
IDE_PDD11
IDE_PDD12
IDE_PDD13
IDE_PDD14
IDE_PDD15
IDE_PDA0 23
IDE_PDA1 23
IDE_PDA2 23
IDE_SDA0 23
IDE_SDA1 23
IDE_SDA2 23
IDE_PDD[15:0] 23
IDE_SDD0
IDE_SDD1
IDE_SDD2
IDE_SDD3
IDE_SDD4
IDE_SDD5
IDE_SDD6
IDE_SDD7
IDE_SDD8
IDE_SDD9
IDE_SDD10
IDE_SDD11
IDE_SDD12
IDE_SDD13
IDE_SDD14
IDE_SDD15
W17
AB17
W16
AC16
W15
AB15
W14
AA14
Y14
AC15
AA15
Y15
AB16
Y16
AA17
Y17
IDE_SDD0
IDE_SDD1
IDE_SDD2
IDE_SDD3
IDE_SDD4
IDE_SDD5
IDE_SDD6
IDE_SDD7
IDE_SDD8
IDE_SDD9
IDE_SDD10
IDE_SDD11
IDE_SDD12
IDE_SDD13
IDE_SDD14
IDE_SDD15
IDE_PDDACK#
IDE_SDDACK#
IDE_PDDREQ
IDE_SDDREQ
IDE_PDIOR#
IDE_SDIOR#
IDE_PDIOW#
IDE_SDIOW#
IDE_PIORDY
IDE_SIORDY
Y12
AB19
AA11
AB18
AC12
Y18
W12
AA18
AB12
AC19
IDE_PDDACK# 23
IDE_SDDACK# 23
IDE_PDDREQ 23
IDE_SDDREQ 23
IDE_PDIOR# 23
IDE_SDIOR# 23
IDE_PDIOW# 23
IDE_SDIOW# 23
IDE_PIORDY 23
IDE_SIORDY 23
CLK_14
CLK_48
RTCRST#
CLK_RTCX1
CLK_RTCX2
CLK_VBIAS
J23
F19
W7
AC7
AC6
Y6
CLK_ICH14 14
CLK_ICH48 14
SPKR
THRMTRIP#
H23
W20 PM_THRMTRIP#_D
AC_SPKR 24
PART B
PM_GMUXSEL/GPIO23
PM_CPUPERF#/GPIO22
PM_VGATE/VRMPWRGD
E
IDE_PDCS1#
IDE_PDCS3#
IDE_SDCS1#
IDE_SDCS3#
ICH4-M
34 PM_CPUPERF#
34,36 VR_PWRGD_ICH
24
24
24
24
24
24
NO_STUFF_1K
R454
ICH_S#1
ICH_S#3
ICH_S#4
ICH_S#5
IST
8.2K
+V3.3S_ICH 17,18,19,21,34
0
0
0
0
Power
Management
NO STUFF
No Reboot
IDE
I/F
Function
R228
D
U42B
R2 PM_AGPBUSY#/GPIO6
Y3 PM_SYSRST#
AB2 PM_BATLOW#
T3 PM_C3_STAT#/GPIO21
AC2 PM_CLKRUN#/GPIO24
V20 PM_DPRSLPVR
AA1 PM_PWRBTN#
AB6 PM_PWROK
Y1 PM_RI#
AA6 PM_RSMRST#
W18 PM_SLP_S1#/GPIO19
Y4 PM_SLP_S3#
Y2 PM_SLP_S4#
AA2 PM_SLP_S5#
W19 PM_STPCPU#/GPIO20
Y21 PM_STPPCI#/GPIO18
AA4 PM_SUS_CLK
AB3 PM_SUS_STAT#/LPCPD#
V1 PM_THRM#
Unmuxed
GPIO
C
Clocks
B
Misc
A
1
23
23
23
23
4
2
J74
J89
1
2
NO_STUFF_MFG-TEST-JUMPER
3
IDE_SDD[15:0]
23
+VCCP 3,4,5,7,15,17,37,39,42
R519
56
PM_THRMTRIP# 3
R514
56
ICH4-M
RTC_RST#
RTC_VBIAS
RTC_X1
RTC_X2
C597
10PF
Y4
32.768KHZ
1
R313
10M
Title
Size
A
Date:
C310
10PF
A
2
B
C
ICH4-M (2 of 3)
Project:
Document Number
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
16
of
E
47
A
B
C
D
R319
U42C
0.01_1%
R231
C283
C495
C595
C490
10UF
0.1UF
0.1UF
0.1UF
+V1.5_ICHLAN
4
0.01_1%
VCCSUS1.5_0
VCCSUS1.5_1
VCCSUS1.5_2
VCCSUS1.5_3
VCCSUS1.5_4
VCCSUS1.5_5
VCCSUS1.5_6
VCCSUS1.5_7
C278
C503 C504
22UF
0.1UF 0.1UF
F6
F7
VCCLAN1.5_0
VCCLAN1.5_1
15 +V3.3_ICHLAN
E9
F9
VCCLAN3.3_0
VCCLAN3.3_1
E7
V6
VCC5REF1
VCC5REF2
+V3.3 7,9,15,20,24,27,29,32,34,36,40,41
R235
VCC5REF
C282
C497 C480
C281
22UF
0.1UF 0.1UF
4.7UF
+V5A_ICH
4,7,8,41 +V1.8S
3
VCC5REFSUS1
L23
M14
P18
T22
VCCHI_0
VCCHI_1
VCCHI_2
VCCHI_3
C297
C492 C493
22UF
0.1UF 0.1UF
R449
VCCPLL
C477
0.1UF
0.01UF
VCCRTC
AB5
VCCSUS3.3_0
VCCSUS3.3_1
VCCSUS3.3_2
VCCSUS3.3_3
VCCSUS3.3_4
VCCSUS3.3_5
VCCSUS3.3_6
VCCSUS3.3_7
VCCSUS3.3_8
VCCSUS3.3_9
E11
F10
F15
F16
F18
K14
V7
V8
V9
F17
C308
C519 C520 C510 C307 C508 C511
22UF
0.1UF 0.1UF 0.1UF 0.1UF 0.1UF 0.1UF
1
NO_STUFF_0.01_1%
C525
C529
C527
1UF
0.1UF
0.1UF
+V1.5S 4,6,7,9,41
C496
VCC5REF
5,9,16,18,19,20,24,25,26,29,33,34,36,41
18,25,26
C517
C512
22UF
0.1UF
0.1UF
0.01_1%
16,18 +V_RTC
C311
0.1UF
VCCPLL
VCC_CPU_IO_0
VCC_CPU_IO_1
VCC_CPU_IO_2
3
5,9,16,18,19,20,24,25,26,29,33,34,36,41
18,34 +V3.3ALWAYS_ICH
R201
C275
C481 C596 C479
22UF
0.1UF 0.1UF 0.1UF
+V3.3ALWAYS
0.01_1%
ICH4-M
R430
1K
5,9,16,18,19,20,24,25,26,29,33,34,36,41
R310
10K
+V3.3ALWAYS
U49
CR22
BAT54
+V5A_ICH
3
C268
C269
1UF
0.1UF
C306
1
IN
2
GND
3
10UF
OUT
5
POK
4
9 +V1.5
18,19,20,24,34,40,41
U50
SI3442DY
6
5
2
1
R322
10K
MAX8888
+V3.3ALWAYS
R316
C302
20k_1% 10UF
0.1UF
C314
G19
G21
H1
J6
K3
K11
K13
K19
K23
L10
L11
L12
L13
L14
L21
M1
M11
M12
M13
M20
M22
N5
N10
N11
N12
N13
N14
N19
N21
N23
P3
P11
P13
P20
P22
R5
R18
R21
T1
T19
T23
U20
V3
V15
V17
W5
W8
W22
Y7
Y19
U42D
R320
1K
4
B
Q46
BSS138
1
R318
2 POK_D
CR13B
3904
5
470
1
Q47
BSS138
1
2
6
1
DC_SLP_S5# 40,41
Title
Size
A
Date:
A
C
2
2
VSS
ICH4-M
3
CR13A
3904
A1 VSS0
A4 VSS1
A16 VSS2
A18 VSS3
A20 VSS4
A22 VSS5
AA3 VSS6
AA9 VSS7
AA12 VSS8
AA16 VSS9
AA22 VSS10
AB7 VSS11
AB20 VSS12
AC1 VSS13
AC5 VSS14
AC10VSS15
AC14VSS16
AC18VSS17
AC23VSS18
B9 VSS19
B12 VSS20
B16 VSS21
B18 VSS22
B20 VSS23
B22 VSS24
C6 VSS25
C15 VSS26
C17 VSS27
C19 VSS28
C21 VSS29
C23 VSS30
D1 VSS31
D4 VSS32
D8 VSS33
D12 VSS34
D15 VSS35
D17 VSS36
D19 VSS37
D21 VSS38
D22 VSS39
D23 VSS40
E10 VSS41
E14 VSS42
E16 VSS43
E17 VSS44
E18 VSS45
E19 VSS46
E21 VSS47
E22 VSS48
F8 VSS49
G3 VSS50
G6 VSS51
1
POK_DQ
36 V1.5_PWRGD
C312
10UF
R324
1K
3
VSS52
VSS53
VSS54
VSS55
VSS56
VSS57
VSS58
VSS59
VSS60
VSS61
VSS62
VSS63
VSS64
VSS65
VSS66
VSS67
VSS68
VSS69
VSS70
VSS71
VSS72
VSS73
VSS74
VSS75
VSS76
VSS77
VSS78
VSS79
VSS80
VSS81
VSS82
VSS83
VSS84
VSS85
VSS86
VSS87
VSS88
VSS89
VSS90
VSS91
VSS92
VSS93
VSS94
VSS95
VSS96
VSS97
VSS98
VSS99
VSS100
VSS101
R325
10K
SHDN#
5,9,16,18,19,20,24,25,26,29,33,34,36,41
ICH4-M
+V5
4
POK
2
2
0.1UF
+V3.3ALWAYS
1
+V5_ALWAYS
C528
1UF
C284
9 +V1.5
1
1
3
2
4
R218
+V1.5ALWAYS
CR20
BAT54
0.01_1%
+V1.5S_ICH
1
R215
1K
+V3.3S
R273
2
9,20,21,24,31,32,33,35,36,37,38,41,42
+V3.3S_ICH 16,18,19,21,34
P14
U18
AA23
STUFF R279 for power
measurement
R279
+V5S
VCC1.5_0
VCC1.5_1
VCC1.5_2
VCC1.5_3
VCC1.5_4
VCC1.5_5
VCC1.5_6
VCC1.5_7
5,9,10,14,15,18,20,23,28,30,31,32,33,36,37,38,41,42
+VCCP
C22
C474
A5
B2
H6
H18
J1
J18
K6
M10
P6
P12
U1
V10
V16
V18
AC8
AC17
K10
K12
K18
K22
P10
T18
U19
V14
POWER
E15
4,6,7,9,41 +V1.5S
0
ICH4-M
15 +V1.8S_ICHHUB
R257
0.01_1%
3,4,5,7,15,16,37,39,42
VCC3.3_0
VCC3.3_1
VCC3.3_2
VCC3.3_3
VCC3.3_4
VCC3.3_5
VCC3.3_6
VCC3.3_7
VCC3.3_8
VCC3.3_9
VCC3.3_10
VCC3.3_11
VCC3.3_12
VCC3.3_13
VCC3.3_14
VCC3.3_15
3
0.01_1%
16,18,19,21,34 +V3.3S_ICH
E12
E13
E20
F14
G18
R6
T6
U6
3 DC_SLP_S5#_Q2
9 +V1.5
E
+V1.5A_ICH
DC_SLP_S5#_Q1
+V1.5ALWAYS
ICH4-M (3 of 3)
Project:
Document Number
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
17
of
E
47
A
B
C
17,34 +V3.3ALWAYS_ICH
ICH4 Pullups
RP56C
RP84A
16,32,34 PM_RI#
15,34 SMB_ALERT#
5,9,16,17,19,20,24,25,26,29,33,34,36,41
6 10K
8 10K
3
1
17,19,20,24,34,40,41
D
E
+V3.3ALWAYS
+VDC 36,37,38,41
+V5
R33
100K_1%
+V5_ALWAYS Generation
16,17,19,21,34 +V3.3S_ICH
15,34 SM_INTRUDER#
RUN_SS
R277
5,16,29,34 PM_THRM#
COSC
2
RUN/SS
TG
16
V5A_TG
BOOST
15
V5A_BOOST
C46
1
2
17,25,26
1
L4
0.47uF
3
V5A_ITH
R48
37.4k_1%
14
V5A_SW
VIN
13
CR3
MBR0520LT1
INTVCC
12
V5A_INTVCC
ITH
SW
8
SGND
7
VOSENSE
5
SENSE-
BG
11
6
SENSE+
PGND
10
1
1
C52
3300pF
6
Q16B
Si4966DY
1
C44
330pF
2
2
4.7uH
C35
C56
C72
1UF
10UF
0.1UF
0.01_1%
CR6
B320A
4
2
1
V5A_BG
+V5_ALWAYS
R53
5
C45
47pF
4
Q16A
Si4966DY
2
2
C48
47pF
1
Vout=0.8(1+Rtop/Rbot)
Vout=0.8(1+(3.92k/750))= 4.98V
IMAX OUT = 50mV / 10mohms = 5A
7
4
U16
V5A_COSC
100K
5,9,10,14,15,17,20,23,28,30,31,32,33,36,37,38,41,42
8
R59
NO_STUFF_680K
16,17 +V_RTC
R329
V5A_PWRGD
V5A_BG_D
36
1
8.2K
8.2K
8.2K
8.2K
8.2K
8.2K
8.2K
8.2K
8.2K
8.2K
8.2K
8.2K
8.2K
8.2K
8.2K
8.2K
8.2K
8.2K
8.2K
8.2K
8.2K
8.2K
8.2K
10K
10K
10K
PGOOD
5
6
6
7
8
8
5
7
6
6
8
7
5
5
8
8
8
7
5
8
6
7
5
8
7
5
9
4
3
3
2
1
1
4
2
3
3
1
2
4
4
1
1
1
2
4
1
3
2
4
1
2
4
EXTVCC
PCI_FRAME#
PCI_IRDY#
PCI_TRDY#
PCI_STOP#
PCI_SERR#
PCI_DEVSEL#
PCI_PERR#
PCI_LOCK#
15 PCI_REQ0#
15,19 PCI_REQ1#
15,19 PCI_REQ2#
15,20 PCI_REQ3#
15,21 PCI_REQ4#
15,23,34 INT_IRQ14
15,23,34 INT_IRQ15
9,15,19,20,21 INT_PIRQA#
9,15,19,20,21 INT_PIRQB#
15,19,20,21 INT_PIRQC#
15,19,20,21 INT_PIRQD#
15,20 INT_PIRQE#
15,20 INT_PIRQF#
15,20 INT_PIRQG#
15,20,34 INT_PIRQH#
19,20 PCI_REQ64#
19,20 PCI_ACK64#
16,29,31,34 PM_CLKRUN#
R54
10_1%
3
R55
10_1%
3
2
3
RP54D
RP55C
RP54C
RP54B
RP54A
RP55A
RP55D
RP55B
RP51C
RP50C
RP48A
RP51B
RP51D
RP85D
RP85A
RP51A
RP50A
RP50B
RP50D
RP16A
RP16C
RP16B
RP16D
RP10A
RP10B
RP69D
15,19,20,21
15,19,20,21
15,19,20,21
15,19,20,21
15,19,20,21
15,19,20,21
15,19,20
15,19,20,21
V5A_ITH_D
4
C63
LTC1735-1
47pF
V5A_SENSE+
+V3.3S
C54
1000PF
8.2K
R61
3.92k_1%
V5A_SENSEV5A_VOSENSE
R317
R323
16,22,29,34,36 PM_PWROK
16,29,34 PM_RSMRST#
100K
100K
R56
750_1%
17,34 +V3.3ALWAYS_ICH
AOL II LAN SUPPORT
7
FAB REVISION
R307
4.7K
16,17,19,21,34 +V3.3S_ICH
RP84B
10K
2
2
2
R176
NO_STUFF_10K
3
SMLINK0 15,19,20
9,14,20,24,34,41 +V12S
R175
NO_STUFF_10K
R189
10K
+VDC 36,37,38,41
16 ICH_FAB_REV0
16 ICH_FAB_REV1
16 ICH_FAB_REV2
2
1
Q48
BSS138
SMB_CLK 10,14,15,21
R187
10K
6
17,34 +V3.3ALWAYS_ICH
R315
4.7K
RP84C
10K
R186
10K
17,25,26
+V5_ALWAYS
C344
C40
C67
C69
0.1UF
22UF
150uF
0.1UF
R178
NO_STUFF_10K
Q45 and Q48 connect SMLINK
and SMBUS in S0 for SMBus
2.0 compliance.
3
R57
GND_V5A
SMLINK1 15,19,20
3
FAB ID Strapping Table
0
ICH_FAB_REV
2
1
0
9,14,20,24,34,41 +V12S
1
Q45
BSS138
SMB_DATA 10,14,15,21
2
0
0
0
0
1
1
1
1
+V3.3S_ICH
16,17,19,21,34
4
3
2
1
1
J92
0
0
1
1
0
0
1
1
BOARD FAB
1
2
3
4
5
6
7
8
0
1
0
1
0
1
0
1
CON4_HDR
A
B
C
1
Title
Size
A
Date:
+V5_ALWAYS VR, ICH4-M Pullups and Testpoints
Project:
Document Number
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
18
of
E
47
A
B
C
D
20 +V12S_PCI
E
20,41 -V12S
20,41 -V12S
+V12S_PCI 20
+V3.3ALWAYS 5,9,16,17,18,20,24,25,26,29,33,34,36,41
20 +V5S_PCI
20 +V3.3S_PCI
20 +V5_PCI
4
9,15,18,20,21 INT_PIRQB#
15,18,20,21 INT_PIRQD#
C84
0.01UF
SLT1_PRSNT1#
C88
0.01UF
SLT1_PRSNT2#
15,20,21,29,31,34 INT_SERIRQ
14 CLK_PCI_SLOT1
15,18 PCI_REQ1#
15,20,21 PCI_AD31
15,20,21 PCI_AD29
15,20,21 PCI_AD27
15,20,21 PCI_AD25
3
15,20,21 PCI_C/BE3#
15,20,21 PCI_AD23
15,20,21 PCI_AD21
15,20,21 PCI_AD19
15,20,21 PCI_AD17
15,20,21 PCI_C/BE2#
15,18,20,21 PCI_IRDY#
15,18,20,21 PCI_DEVSEL#
15,18,20,21 PCI_LOCK#
15,18,20 PCI_PERR#
15,18,20,21 PCI_SERR#
15,20,21 PCI_C/BE1#
15,20,21 PCI_AD14
15,20,21 PCI_AD12
15,20,21 PCI_AD10
2
15,20,21 PCI_AD8
15,20,21 PCI_AD7
15,20,21 PCI_AD5
15,20,21 PCI_AD3
15,20,21 PCI_AD1
18,20 PCI_ACK64#
20 +V5_PCI
B1
B2
B3
B4
B5
B6
B7
B8
B9
B10
B11
B12
B13
B14
B15
B16
B17
B18
B19
B20
B21
B22
B23
B24
B25
B26
B27
B28
B29
B30
B31
B32
B33
B34
B35
B36
B37
B38
B39
B40
B41
B42
B43
B44
B45
B46
B47
B48
B49
TRST#
-12V
+12V
TCK
TMS
GND1
TDI
TDO
+5V (7)
+5V (1)
INTA#
+5V (2)
INTC#
INTB#
+5V (8)
INTD#
RSV3
PRSNT1#
+5V (9)
RSV1
RSV4
PRSNT2#
GND14
GND2
GND15
GND3
RSV5
RSV2
RST#
GND4
+5V (10)
CLK
GNT#
GND5
GND16
REQ#
PME#
+5V (3)
AD30
AD31
+3.3V (7)
AD29
AD28
GND6
AD26
AD27
GND17
AD25
AD24
+3.3V (1)
IDSEL
C/BE3#
+3.3V (8)
AD23
AD22
GND8
AD20
AD21
GND18
AD19
AD18
+3.3V (2)
AD16
AD17
+3.3V (9)
C/BE2#
FRAME#
GND9
GND19
IRDY#
TRDY#
+3.3V (3)
GND20
DEVSEL#
STOP#
GND10
+3.3V (10)
LOCK#
SDONE
PERR#
SBO#
+3.3V (4)
GND21
SERR#
PAR
+3.3V (5)
AD15
C/BE1#
+3.3V (11)
AD14
AD13
GND11
AD11
AD12
GND22
AD10
AD09
GND12
KEY
B52
B53
B54
B55
B56
B57
B58
B59
B60
B61
B62
C/BE0#
AD08
+3.3V (12)
AD07
AD06
+3.3V (6)
AD04
AD05
GND23
AD03
AD02
GND13
AD00
AD01
+5V (11)
+5V (4)
REQ64#
ACK64#
+5V (12)
+5V (5)
+5V (13)
+5V (6)
J19
+V3.3ALWAYS 5,9,16,17,18,20,24,25,26,29,33,34,36,41
+V5S_PCI 20
20 +V5S_PCI
A1
+V3.3S_PCI 20
A2
20 +V3.3S_PCI
A3
A4
A5
15,18,20,21 INT_PIRQC#
A6
INT_PIRQA# 9,15,18,20,21 9,15,18,20,21 INT_PIRQA#
A7
INT_PIRQC# 15,18,20,21
A8
C350
SLT2_PRSNT1#
A9
PCI_CLKRUN# 20,21
A10
0.01UF
C87 SLT2_PRSNT2#
A11
PCI_GATED_RST# 9,20,29,34
A12
0.01UF
A13
A14
15,20,21,29,31,34 INT_SERIRQ
A15
BUF_PCI_RST# 9,15,20,21,29,30,31,34
A16
14 CLK_PCI_SLOT2
A17
PCI_GNT1# 15
A18
15,18 PCI_REQ2#
A19
PCI_PME# 9,15,20,34
A20
PCI_AD30 15,20,21
15,20,21 PCI_AD31
A21
15,20,21 PCI_AD29
A22
PCI_AD28 15,20,21
A23
PCI_AD26 15,20,21
15,20,21 PCI_AD27
A24
15,20,21 PCI_AD25
A25
PCI_AD24 15,20,21
SLT1_IDSEL
A26
PCI_AD25 15,20,21 15,20,21 PCI_C/BE3#
R91
680
A27
15,20,21 PCI_AD23
A28
PCI_AD22 15,20,21
A29
PCI_AD20 15,20,21
15,20,21 PCI_AD21
A30
15,20,21 PCI_AD19
A31
PCI_AD18 15,20,21
A32
PCI_AD16 15,20,21
15,20,21 PCI_AD17
A33
15,20,21 PCI_C/BE2#
A34
PCI_FRAME# 15,18,20,21
A35
15,18,20,21 PCI_IRDY#
A36
PCI_TRDY# 15,18,20,21
A37
15,18,20,21 PCI_DEVSEL#
A38
PCI_STOP# 15,18,20,21
A39
15,18,20,21 PCI_LOCK#
A40
15,18,20 PCI_PERR#
SMLINK0 15,18,20
A41
SMLINK1 15,18,20
A42
15,18,20,21 PCI_SERR#
A43
PCI_PAR 15,20,21
A44
PCI_AD15 15,20,21
15,20,21 PCI_C/BE1#
A45
15,20,21 PCI_AD14
A46
PCI_AD13 15,20,21
A47
PCI_AD11 15,20,21
15,20,21 PCI_AD12
A48
15,20,21 PCI_AD10
A49
PCI_AD9 15,20,21
B1
B2
B3
B4
B5
B6
B7
B8
B9
B10
B11
B12
B13
B14
B15
B16
B17
B18
B19
B20
B21
B22
B23
B24
B25
B26
B27
B28
B29
B30
B31
B32
B33
B34
B35
B36
B37
B38
B39
B40
B41
B42
B43
B44
B45
B46
B47
B48
B49
TRST#
-12V
+12V
TCK
TMS
GND1
TDI
TDO
+5V (7)
+5V (1)
INTA#
+5V (2)
INTC#
INTB#
+5V (8)
INTD#
RSV3
PRSNT1#
+5V (9)
RSV1
RSV4
PRSNT2#
GND14
GND2
GND15
GND3
RSV5
RSV2
RST#
GND4
+5V (10)
CLK
GNT#
GND5
GND16
REQ#
PME#
+5V (3)
AD30
AD31
+3.3V (7)
AD29
AD28
GND6
AD26
AD27
GND17
AD25
AD24
+3.3V (1)
IDSEL
C/BE3#
+3.3V (8)
AD23
AD22
GND8
AD20
AD21
GND18
AD19
AD18
+3.3V (2)
AD16
AD17
+3.3V (9)
C/BE2#
FRAME#
GND9
GND19
IRDY#
TRDY#
+3.3V (3)
GND20
DEVSEL#
STOP#
GND10
+3.3V (10)
LOCK#
SDONE
PERR#
SBO#
+3.3V (4)
GND21
SERR#
PAR
+3.3V (5)
AD15
C/BE1#
+3.3V (11)
AD14
AD13
GND11
AD11
AD12
GND22
AD10
AD09
GND12
KEY
A52
A53
A54
A55
A56
A57
A58
A59
A60
A61
A62
B52
B53
B54
B55
B56
B57
B58
B59
B60
B61
B62
C/BE0#
AD08
+3.3V (12)
AD07
AD06
+3.3V (6)
AD04
AD05
GND23
AD03
AD02
GND13
AD00
AD01
+5V (11)
+5V (4)
REQ64#
ACK64#
+5V (12)
+5V (5)
+5V (13)
+5V (6)
PCI_C/BE0# 15,20,21
PCI_AD6 15,20,21
PCI_AD4 15,20,21
PCI_AD2 15,20,21
PCI_AD0 15,20,21
PCI_REQ64# 18,20
15,20,21 PCI_AD8
15,20,21 PCI_AD7
15,20,21 PCI_AD5
15,20,21 PCI_AD3
15,20,21 PCI_AD1
18,20 PCI_ACK64#
CON120_PCI
J18
SLOT1
+V5S_PCI 20
A1
A2
20 +V3.3S_PCI
A3
A4
A5
A6
INT_PIRQB# 9,15,18,20,21
A7
INT_PIRQD# 15,18,20,21
A8
A9
PCI_CLKRUN# 20,21
A10
A11
PCI_GATED_RST# 9,20,29,34
A12
A13
A14
9,15,20,21,29,30,31,34
A15
BUF_PCI_RST#
A16
A17
PCI_GNT2# 15
A18
A19
PCI_PME# 9,15,20,34
A20
PCI_AD30 15,20,21
A21
A22
PCI_AD28 15,20,21
A23
PCI_AD26 15,20,21
A24
A25
PCI_AD24 15,20,21
SLT2_IDSEL
A26
R90
680
A27
A28
PCI_AD22 15,20,21
A29
PCI_AD20 15,20,21
A30
A31
PCI_AD18 15,20,21
A32
PCI_AD16 15,20,21
A33
A34
PCI_FRAME# 15,18,20,21
A35
A36
PCI_TRDY# 15,18,20,21
A37
A38
PCI_STOP# 15,18,20,21
A39
A40
SMLINK0 15,18,20
A41
SMLINK1 15,18,20
A42
A43
PCI_PAR 15,20,21
A44
PCI_AD15 15,20,21
A45
A46
PCI_AD13 15,20,21
A47
PCI_AD11 15,20,21
A48
A49
PCI_AD9 15,20,21
4
3
2
A52
A53
A54
A55
A56
A57
A58
A59
A60
A61
A62
PCI_C/BE0# 15,20,21
PCI_AD6 15,20,21
PCI_AD4 15,20,21
PCI_AD2 15,20,21
PCI_AD0 15,20,21
PCI_REQ64# 18,20
CON120_PCI
SLOT2
16,17,18,21,34 +V3.3S_ICH
17,18,20,24,34,40,41
+V5
20 +V5_PCI
R425
8.2K
J51
1
15,16 PCI_GNTA#
1
LEGACY HEADER
FOR ADD-IN
AUDIO CARD
TESTING
5
2
4
6
R362
NO_STUFF_0
PCI_REQA# 15
INT_SERIRQ 15,20,21,29,31,34
1
5Pin_Keyed-HDR
R424
8.2K
Title
16,17,18,21,34 +V3.3S_ICH
Size
A
Date:
A
B
C
PCI Slot 1 & 2
Project:
Document Number
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
19
of
E
47
A
B
C
D
E
1 RP8A
0
8
INT_PIRQC# 15,18,19,21
19,41 -V12S
+V5PCISLT3
19 +V3.3S_PCI
+V5_PCI 19
+V3.3PCISLT3
5,9,16,17,18,19,24,25,26,29,33,34,36,41 +V3.3ALWAYS
+V5PCISLT3
19 +V12S_PCI
R94
0
7,9,15,17,24,27,29,32,34,36,40,41
2 RP8B
0
+V3.3
INT_PIRQE# 15,18
7
INT_PIRQA# 9,15,18,19,21
+V3.3PCISLT3
4
15,18,19,21 INT_PIRQD#
3
15,18 INT_PIRQF#
3
9,15,18,19,21 INT_PIRQB#
4
4
15,18,34 INT_PIRQH#
R73
NO_STUFF_0
RP8C 6
0
RP18C 6
NO_STUFF_0
RP8D 5
0
RP18D 5
NO_STUFF_0
PCI_SLT3INTB#
PCI_SLT3INTD#
C352
0.01UF
19 +V5S_PCI
17,18,19,24,34,40,41
SLT3_PRSNT1#
C89
SLT3_PRSNT2#
0.01UF
R58
0
15,19,21,29,31,34 INT_SERIRQ
+V5
14 CLK_PCI_SLOT3
R51
NO_STUFF_0
15,18 PCI_REQ3#
15,19,21 PCI_AD31
15,19,21 PCI_AD29
15,19,21 PCI_AD27
15,19,21 PCI_AD25
3
15,19,21 PCI_C/BE3#
15,19,21 PCI_AD23
+V5PCISLT3
Place close to slot 3
15,19,21 PCI_AD21
15,19,21 PCI_AD19
C90
C197
C60
C202
C70
22UF
0.1UF
0.1UF
0.1UF
0.1UF
15,19,21 PCI_AD17
15,19,21 PCI_C/BE2#
+V3.3PCISLT3
15,18,19,21 PCI_IRDY#
Place close to slot 3
C175
C156
C99
C187
C130
C183
C169
22UF
22UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
15,18,19,21 PCI_DEVSEL#
15,19,21 PCI_C/BE1#
15,19,21 PCI_AD14
+V5S 9,17,21,24,31,32,33,35,36,37,38,41,42
2
Layout Note:
Place half of these caps by PCI slot 1, the other
half by PCI slot2
R121
0.01_1%
15,19,21 PCI_AD12
15,19,21 PCI_AD10
19 +V5S_PCI
15,19,21 PCI_AD8
15,19,21 PCI_AD7
C208
C81
C66
C195
C50
C203
C93
C95
C94
22UF
22UF
22UF
22UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
15,19,21 PCI_AD5
15,19,21 PCI_AD3
15,19,21 PCI_AD1
18,19 PCI_ACK64#
C58
C59
C198
C85
C96
C74
C196
C194
C68
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
B1
B2
B3
B4
B5
B6
B7
B8
B9
B10
B11
B12
B13
B14
B15
B16
B17
B18
B19
B20
B21
B22
B23
B24
B25
B26
B27
B28
B29
B30
B31
B32
B33
B34
B35
B36
B37
B38
B39
B40
B41
B42
B43
B44
B45
B46
B47
B48
B49
TRST#
-12V
+12V
TCK
TMS
GND1
TDI
TDO
+5V (7)
+5V (1)
INTA#
+5V (2)
INTC#
INTB#
+5V (8)
INTD#
RSV3
PRSNT1#
+5V (9)
RSV1
RSV4
PRSNT2#
GND14
GND2
GND15
GND3
RSV5
RSV2
RST#
GND4
+5V (10)
CLK
GNT#
GND5
GND16
REQ#
PME#
+5V (3)
AD30
AD31
+3.3V (7)
AD29
AD28
GND6
AD26
AD27
GND17
AD25
AD24
+3.3V (1)
IDSEL
C/BE3#
+3.3V (8)
AD23
AD22
GND8
AD20
AD21
GND18
AD19
AD18
+3.3V (2)
AD16
AD17
+3.3V (9)
C/BE2#
FRAME#
GND9
GND19
IRDY#
TRDY#
+3.3V (3)
GND20
DEVSEL#
STOP#
GND10
+3.3V (10)
LOCK#
SDONE
PERR#
SBO#
+3.3V (4)
GND21
SERR#
PAR
+3.3V (5)
AD15
C/BE1#
+3.3V (11)
AD14
AD13
GND11
AD11
AD12
GND22
AD10
AD09
GND12
KEY
A1
A2
A3
A4
A5
A6
A7
A8
A9
A10
A11
A12
A13
A14
A15
A16
A17
A18
A19
A20
A21
A22
A23
A24
A25
A26 SLT3_IDSEL
A27
A28
A29
A30
A31
A32
A33
A34
A35
A36
A37
A38
A39
A40
A41
A42
A43
A44
A45
A46
A47
A48
A49
B52
B53
B54
B55
B56
B57
B58
B59
B60
B61
B62
C/BE0#
AD08
+3.3V (12)
AD07
AD06
+3.3V (6)
AD04
AD05
GND23
AD03
AD02
GND13
AD00
AD01
+5V (11)
+5V (4)
REQ64#
ACK64#
+5V (12)
+5V (5)
+5V (13)
+5V (6)
A52
A53
A54
A55
A56
A57
A58
A59
A60
A61
A62
J17
9,14,18,24,34,41 +V12S
PCI_CLKRUN# 19,21
PCI_GATED_RST# 9,19,29,34
PCIRST#
R365
NO_STUFF_0
R364
0
9,15,19,21,29,30,31,34
BUF_PCI_RST#
S3_PCI_GNT3#
PCI_PME# 9,15,19,34
PCI_AD30 15,19,21
PCI_AD28 15,19,21
PCI_AD26 15,19,21
R98
3
PCI_AD24 15,19,21
PCI_AD27 15,19,21
680
PCI_AD22 15,19,21
PCI_AD20 15,19,21
PCI_AD18 15,19,21
PCI_AD16 15,19,21
19 +V3.3S_PCI
PCI_FRAME# 15,18,19,21
PCI_TRDY# 15,18,19,21
+V3.3PCISLT3
R124
1K
R128
10K
PCI_STOP# 15,18,19,21
SMLINK0 15,18,19
SMLINK1 15,18,19
PCI_PAR 15,19,21
PCI_AD15 15,19,21
PCI_AD13 15,19,21
PCI_AD11 15,19,21
3
Q27
2N3904
1
PCI_AD9 15,19,21
2
2
PCI_GNT3# 15
PCI_C/BE0# 15,19,21
PCI_AD6 15,19,21
PCI_AD4 15,19,21
PCI_AD2 15,19,21
PCI_AD0 15,19,21
PCI_REQ64# 18,19
CON120_PCI
To Power PCI Slot 3 in Suspend
STUFF:
R73,R51,R365
UN-STUFF: R94,R58,R364
(default is no power in suspend)
19 +V12S_PCI
R37
R120
INT_PIRQG# 15,18
PCI_SLT3INTA#
PCI_SLT3INTC#
SLOT3
+V3.3S 5,9,10,14,15,17,18,23,28,30,31,32,33,36,37,38,41,42
4
2 RP18B 7
NO_STUFF_0
V3.3S_PCI_D
15,18,19,21 PCI_LOCK#
15,18,19 PCI_PERR#
15,18,19,21 PCI_SERR#
1
1 RP18A 8
NO_STUFF_0
1
0.01_1%
19 +V3.3S_PCI
0.01_1%
C181
C182
C153
C172
C146
C160
C154
C148
C100
C101
C149
C185
C184
C186
C47
22UF
22UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
10UF
C51
Title
C53
0.1UF
0.1UF
A
B
C
Size
A
Date:
PCI Slot 3 & Decoupling
Project:
Document Number
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
20
of
E
47
A
B
Qbuffers used for isolation during suspend
as well as 5V->3.3V translation
15,19,20 PCI_AD[31:0]
3
9,17,20,24,31,32,33,35,36,37,38,41,42
U24
1
4
PCI_AD22
PCI_AD23
PCI_AD26
PCI_AD27
PCI_AD30
PCI_AD31
PCI_AD29
PCI_AD28
PCI_AD25
PCI_AD24
PCI_AD12
PCI_AD14
PCI_AD15
PCI_AD18
PCI_AD19
PCI_AD21
PCI_AD20
PCI_AD17
PCI_AD16
PCI_AD13
22 DOCK_QPCIEN#
C
NC
+V5S
DOCK_QDEN# 22
+V5S_QSPWR
15
2
3
4
5
6
7
9
10
11
12
13
14
16
18
19
20
21
22
23
24
1A1
1A2
1A3
1A4
1A5
1A6
1A7
1A8
1A9
1A10
2A1
2A2
2A3
2A4
2A5
2A6
2A7
2A8
2A9
2A10
1B1
1B2
1B3
1B4
1B5
1B6
1B7
1B8
1B9
1B10
2B1
2B2
2B3
2B4
2B5
2B6
2B7
2B8
2B9
2B10
46
45
44
43
42
40
39
38
37
36
35
34
33
31
30
29
28
27
26
25
48
47
1OE#
2OE#
GND1
GND2
GND3
GND4
8
17
32
41
E
16,17,18,19,34 +V3.3S_ICH
R117
100K
+V5S_QSPWR
VCC
D
DOCK_AD22
DOCK_AD23
DOCK_AD26
DOCK_AD27
DOCK_AD30
DOCK_AD31
DOCK_AD29
DOCK_AD28
DOCK_AD25
DOCK_AD24
DOCK_AD12
DOCK_AD14
DOCK_AD15
DOCK_AD18
DOCK_AD19
DOCK_AD21
DOCK_AD20
DOCK_AD17
DOCK_AD16
DOCK_AD13
R207
8.2K
2
C92
C388
22UF
0.1UF
U25
1
NC
VCC
15
2
3
4
5
6
7
9
10
11
12
13
14
16
18
19
20
21
22
23
24
1A1
1A2
1A3
1A4
1A5
1A6
1A7
1A8
1A9
1A10
2A1
2A2
2A3
2A4
2A5
2A6
2A7
2A8
2A9
2A10
1B1
1B2
1B3
1B4
1B5
1B6
1B7
1B8
1B9
1B10
2B1
2B2
2B3
2B4
2B5
2B6
2B7
2B8
2B9
2B10
46
45
44
43
42
40
39
38
37
36
35
34
33
31
30
29
28
27
26
25
48
47
1OE#
2OE#
GND1
GND2
GND3
GND4
8
17
32
41
1
Q24
BSS84
3
15 PCI_GNTB#
15 PCI_REQB#
15,19,20,29,31,34 INT_SERIRQ
9,15,18,19,20 INT_PIRQA#
9,15,18,19,20 INT_PIRQB#
15,18,19,20 INT_PIRQC#
15,18,19,20 INT_PIRQD#
15,18,19,20 PCI_SERR#
15,19,20 PCI_PAR
15,18,19,20 PCI_IRDY#
15,18,19,20 PCI_DEVSEL#
15,18,19,20 PCI_STOP#
15,18,19,20 PCI_TRDY#
15,18,19,20 PCI_LOCK#
15,18,19,20 PCI_FRAME#
15,19,20 PCI_C/BE3#
15,19,20 PCI_C/BE2#
15,19,20 PCI_C/BE1#
15,19,20 PCI_C/BE0#
DOCK_QPCIEN#
DOCK_AD[31:0] 22
74CBTD16210
4
C407
DOCK_GNTB# 22
DOCK_REQB# 22
DOCK_SERIRQ 22
DOCK_PIRQA# 22
DOCK_PIRQB# 22
DOCK_PIRQC# 22
DOCK_PIRQD# 22
DOCK_SERR# 22
DOCK_PAR 22
DOCK_IRDY# 22
DOCK_DEVSEL# 22
DOCK_STOP# 22
DOCK_TRDY# 22
DOCK_LOCK# 22
DOCK_FRAME# 22
DOCK_C/BE3# 22
DOCK_C/BE2# 22
DOCK_C/BE1# 22
DOCK_C/BE0# 22
0.1UF
3
74CBTD16210
+V5S_QSPWR
U23
1
PCI_AD2
PCI_AD3
PCI_AD6
PCI_AD7
PCI_AD10
PCI_AD11
PCI_AD9
PCI_AD8
PCI_AD5
PCI_AD4
10,14,15,18 SMB_DATA
PCI_AD1
PCI_AD0
2
10,14,15,18 SMB_CLK
DOCK_QPCIEN#
NC
VCC
15
2
3
4
5
6
7
9
10
11
12
13
14
16
18
19
20
21
22
23
24
1A1
1A2
1A3
1A4
1A5
1A6
1A7
1A8
1A9
1A10
2A1
2A2
2A3
2A4
2A5
2A6
2A7
2A8
2A9
2A10
1B1
1B2
1B3
1B4
1B5
1B6
1B7
1B8
1B9
1B10
2B1
2B2
2B3
2B4
2B5
2B6
2B7
2B8
2B9
2B10
46
45
44
43
42
40
39
38
37
36
35
34
33
31
30
29
28
27
26
25
48
47
1OE#
2OE#
GND1
GND2
GND3
GND4
8
17
32
41
DOCK_AD2
DOCK_AD3
DOCK_AD6
DOCK_AD7
DOCK_AD10
DOCK_AD11
DOCK_AD9
DOCK_AD8
DOCK_AD5
DOCK_AD4
DOCK_AD1
DOCK_AD0
C387
0.1UF
+V5S_QSPWR
QUIET DOCK
QSWITCH
U21
9,15,19,20,29,30,31,34
DOCK_SMBDATA 22
3
4
7
8
11
BUF_PCI_RST#
19,20 PCI_CLKRUN#
DOCK_SMBCLK 22
15 PCI_GNT4#
15,18 PCI_REQ4#
14 CLK_DOCKPCI
29,33,34 DOCK_INTR#
OE#
R92
100
1A1
1A2
1A3
1A4
1A5
14
17
18
21
22
2A1
2A2
2A3
2A4
2A5
1
13
1OE#
2OE#
VCC
24
1B1
1B2
1B3
1B4
1B5
2
5
6
9
10
2B1
2B2
2B3
2B4
2B5
15
16
19
20
23
GND
12
C375
0.1UF
DOCK_RESET# 22
2
DOCK_CLKRUN# 22
DOCK_GNT4# 22
DOCK_REQ4# 22
CLK_DOCKCONNPCI 22
DOCK_DOCKINTR# 22
Bus-Switch-74CBT3384
74CBTD16210
1
1
Title
Size
A
Date:
A
B
C
Docking Q-Switches
Document Number
Project:
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
of
21
E
47
B
C
D
E
200
199
150
149
A
100
101
151
102
152
J38A
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
5049
4
5251 2 1
21 DOCK_SMBDATA
21 DOCK_CLKRUN#
21 DOCK_REQB#
21 DOCK_PIRQC#
21 DOCK_PIRQB#
21 DOCK_GNT4#
GND0
V_DC0
V_DC1
GND1
GND2
RED_RTN
RED
VSYNC
HSYNC
GND3
GND4
NC0
SM_DATA
SYSACT#
CLKRUN#
PC_REQ#
GND5
CD2
NC1
NC2
CD3#/GND
INTD#
INTC#
GND6
GNT#
J38C
REQ#
GND7
PERR#
SERR#
GND8
STOP#
TRDY#
GND9
LOCK#
FRAME#
GND10
C/BE1#
C/BE0#
GND11
AD29
AD28
GND12
AD25
AD24
GND13
AD21
AD20
GND14
V_ACDC0
V_ACDC1
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
DOCK_REQ4# 21
DOCK_SERR# 21
DOCK_AD17
DOCK_AD16
DOCK_STOP# 21
DOCK_TRDY# 21
DOCK_AD13
DOCK_AD12
DOCK_LOCK# 21
DOCK_FRAME# 21
DOCK_AD9
DOCK_AD8
DOCK_C/BE1# 21
DOCK_C/BE0# 21
DOCK_AD5
DOCK_AD4
DOCK_AD29
DOCK_AD28
DOCK_AD1
DOCK_AD0
DOCK_AD25
DOCK_AD24
DOCK_AD21
DOCK_AD20
21 CLK_DOCKCONNPCI
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
200Pin_Docking-Plug
LPT_BUSY
LPT_D5
LPT_D4
GND39
ERROR#
LPT_D1
LPT_D0
GND40
SER_OUT
SER_RTS
SER_CTS
SER_DTR
MS_DATA
MS_CLK
GND41
L_LININ
LIN_GND
R_LININ
NC8
MIDI_SRX
MIDI_STX
USB+
USBGND42
DCKINTR#
3V
GND30
NC7
GND31
AD17
AD16
GND32
AD13
AD12
GND33
AD9
AD8
GND34
AD5
AD4
GND35
AD1
AD0
GND36
PCI_CLK
GND37
SLCTIN#
PLT_AFD#
PLT_PE
GND38
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
4
DOCK_USBP5P 26
DOCK_USBP5N 26
DOCK_DOCKINTR# 21
200Pin_Docking-Plug
3
3
21 DOCK_AD[31:0]
J38B
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
21 DOCK_SMBCLK
21 DOCK_SERIRQ
2
21 DOCK_GNTB#
21 DOCK_PIRQA#
21 DOCK_PIRQD#
V_DC2
V_DC3
GND15
GND16
GRN_RTN
GREEN
BLU_RTN
BLUE
DDC_DAT
DDC_CLK
GND17
GND18
SM_CLK
SERINT
NC3
PC_GNT#
GND19
NC4
NC5
NC6
GND20
INTB#
INTA#
GND21
UNDKRQ#
J38D
UNDKGT#
GND22
PAR
PCI_RST#
GND23
IRDY#
DEVSEL#
GND24
C/BE3#
C/BE2#
GND25
AD31
AD30
GND26
AD27
AD26
GND27
AD23
AD22
GND28
AD19
AD18
GND29
V_ACDC2
V_ACDC3
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
DOCK_PAR 21
DOCK_RESET# 21
DOCK_AD15
DOCK_AD14
DOCK_IRDY# 21
DOCK_DEVSEL# 21
DOCK_AD11
DOCK_AD10
DOCK_C/BE3# 21
DOCK_C/BE2# 21
DOCK_AD7
DOCK_AD6
DOCK_AD31
DOCK_AD30
DOCK_AD3
DOCK_AD2
DOCK_AD27
DOCK_AD26
DOCK_AD23
DOCK_AD22
DOCK_AD19
DOCK_AD18
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
21 DOCK_QDEN#
21 DOCK_QPCIEN#
16,18,29,34,36 PM_PWROK
200Pin_Docking-Plug
5V0
5V1
NC9
GND43
AD15
AD14
GND44
AD11
AD10
GND45
AD7
AD6
GND46
AD3
AD2
GND47
SRBTN#
QDEN#
QPCIEN#
NBPWROK
DPWRSW
NC10
LPT_SLCT
LPT_STB#
CD4#/GND
LPT_ACK#
LPT_D7
LPT_D6
GND48
LPT_INIT#
LPT_D3
LPT_D2
GND49
SER_RD
SER_DSR
SER_RI
SER_DCD
KB_DATA
KB_CLK
NC11
L_INOUT
L_O_GND
R_INOUT
NC12
MICIN
MIC_GND
5V_USB
GND_USB
SUSTAT#
CD1#
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
2
200Pin_Docking-Plug
CR14
1 DOCK_SUSTAT#
3
14,16,29,34,40,41 PM_SLP_S3#
BAR43
There is pull-up on
docking station.
1
1
Title
Size
A
Date:
A
B
C
Docking Connector
Project:
Document Number
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
of
22
E
47
A
B
C
D
E
R337
47
16 IDE_PDD[15:0]
4
5,9,10,14,15,17,18,20,28,30,31,32,33,36,37,38,41,42
+V3.3S
4.7K
IDE_D_PRST#
6,15,28,34,42 PCI_RST#
PRIMARY HDD CONN
J93
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
39
IDE_PDD7
IDE_PDD6
IDE_PDD5
IDE_PDD4
IDE_PDD3
IDE_PDD2
IDE_PDD1
IDE_PDD0
R3005
16 IDE_PDDREQ
16 IDE_PDIOW#
16 IDE_PDIOR#
16 IDE_PIORDY
16 IDE_PDDACK#
15,18,34 INT_IRQ14
16 IDE_PDA1
16 IDE_PDA0
16 IDE_PDCS1#
24,41 IDE_PDACTIVE#
2
4
6
8
10
12
14
16
18
22
24
26
28
30
32
34
36
38
40
IDE_PDD[15:0]
16
4
IDE_PDD8
IDE_PDD9
IDE_PDD10
IDE_PDD11
IDE_PDD12
IDE_PDD13
IDE_PDD14
IDE_PDD15
R305
IDE_PD_CSEL
470
IDE_PATADET 16,34
R525
10K
20x2-HDR
16 IDE_PDCS3#
16 IDE_PDA2
3
3
24 IDE_D_SRST#
SECONDARY HDD CONN
J87
16 IDE_SDD[15:0]
5,9,10,14,15,17,18,20,28,30,31,32,33,36,37,38,41,42
IDE_SDD7
IDE_SDD6
IDE_SDD5
IDE_SDD4
IDE_SDD3
IDE_SDD2
IDE_SDD1
IDE_SDD0
+V3.3S
4.7K
R3006
16 IDE_SDDREQ
16 IDE_SDIOW#
16 IDE_SDIOR#
16 IDE_SIORDY
16 IDE_SDDACK#
15,18,34 INT_IRQ15
16 IDE_SDA1
16 IDE_SDA0
16 IDE_SDCS1#
24 IDE_SDACTIVE#
2
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
39
2
4
6
8
10
12
14
16
18
22
24
26
28
30
32
34
36
38
40
IDE_SDD[15:0]
IDE_SDD8
IDE_SDD9
IDE_SDD10
IDE_SDD11
IDE_SDD12
IDE_SDD13
IDE_SDD14
IDE_SDD15
16
R304
IDE_SD_CSEL
2
470
IDE_SATADET 16,34
R302
10K
20x2-HDR
16 IDE_SDCS3#
16 IDE_SDA2
1
1
Title
Size
A
Date:
A
B
C
IDE 1 of 2
Project:
855PM Platform
Monday, February 24, 2003
D
Document Number
Sheet
Rev
23
of
E
47
B
C
0
SHMIDT3 5
14
U47C
74HC14
TP_OPAMPOUT1
6
1
7
R260
D
E
Secondary IDE
Power
+V5S
U47A
74HC14
IDE_SPWR_EN
2
9,17,20,21,31,32,33,35,36,37,38,41,42
C498
0.1UF
7
14
9,17,20,21,31,32,33,35,36,37,38,41,42
4
R266
1M
U47E
74HC14
10 IDE_SPWR2_D
14
A
31,34 IDE_SPWR_EN#
11
+V5S_IDE_S
+V5S
C293
1
1000PF
R270
IDE_SPWR2
4
3
U46A
SI4925DY
2
U46B
SI4925DY
4
R261
NO_STUFF_0
390K
9,17,20,21,31,32,33,35,36,37,38,41,42
+V5S
9
C509
U47D
74HC14
8
14
14
SHMIDT4
R497
1M
PRIMARY IDE
PWR ON DC-DC
MODULE
7
R272
100K
SHMIDT2
3
U47B
74HC14
SHMIDT5
4
R265
47
7
8
+V12S_IDE_S
V5S_IDE_PD
J78
IDE_D_SRST# 23
0.1UF
R271
0.01_1%
7
7
5
6
+V5S_IDE_S
C546
C305 C545 + C301
0.1UF
22UF 0.1UF 100uF
1
2
3
4
4Pin_PwrConn
+V5S
9,17,20,21,31,32,33,35,36,37,38,41,42
9,14,18,20,34,41 +V12S
13
IDE_SPWR_EN_D
Q39
2N7002
IDE_SPWR_EN
J78 Supports Hot
Swap on 2nd IDE
connector only.
R259
1M
R262
1
C290
3
Q41
SI2307DS
1
1000PF
IDE_SPWR_EN_D2
2
7
R486
0
+V12S_IDE_S
3
SHMIDT_PD1
U47F
74HC14
TP_OPAMPOUT2
12
3
14
3
2
390K
+V3.3 7,9,15,17,20,27,29,32,34,36,40,41
+V5S
9,17,20,21,31,32,33,35,36,37,38,41,42
R339
470
MDC INTERPOSER HEADER
IDE Activity LEDs
7,9,15,17,20,27,29,32,34,36,40,41
+V5
17,18,19,20,34,40,41
R278
470
5,9,16,17,18,19,20,25,26,29,33,34,36,41
J43
PM_SUSLEDGND
PM_SUSLED
2
IDE_PLED
1
2
3
4
J75
CON4_HDR
16 AUDIO_PWRDN
16 AC_SYNC
3
1
Q44
BSS138
DS8
GREEN
R174
R196
R216
PM_SLP_S1# 14,16,41
SDATAIN1_D
SDATAIN0_D
33
33
AC_BITCLK_D
33
AC97_BITCLK has
internal pulldown 20K
resistor enabled when
AC_SHUT bit is set
to 1
23,41 IDE_PDACTIVE#
+V5S_IDE_S
1
3
5
7
9
11
13
15
17
19
2
4
6
8
10
12
14
16
18
20
2
AC_SPKR 16
AC_SDATAOUT_D
R190
SDATAIN2_D
R195 33
33
AC_SDATAOUT 16
AC_SDATAIN2 16
AC_RST# 16
2x10-SHD-HDR
R230
NO_STUFF_10K
2
2
1
1
1
16 AC_SDATAIN1
16 AC_SDATAIN0
Q42
BSS138
2
3
2
DS6
GREEN
29,30 SMC_INITCLK
+V3.3ALWAYS
+V3.3
Layout Note:
Place R174, R196 and R195
0.1 to 0.4 inches from MDC
header based on topology
R321
10K
16 AC_BITCLK
1
1
R303
470
23 IDE_SDACTIVE#
Title
2 IDE_SDACTIVE#_Q
1
DS7
GREEN
A
Size
A
Date:
B
C
IDE 2 of 2 / MDC INTERPOSER
Project:
855PM Platform
Monday, February 24, 2003
D
Document Number
Sheet
Rev
of
24
E
47
A
B
17,18,26
C
D
E
+V5_ALWAYS
C39
5,9,16,17,18,19,20,24,26,29,33,34,36,41
+V3.3ALWAYS
0.1UF
+V5_ALWAYS
1
4
17,18,26
2
4
RP4B
10K
USB_OC3# 16
U12
1
2
3
4
EN1_A
EN2_A
GND
IN
EN1
EN2
8
7
6
5
OC1#
OUT1
OUT2
OC2#
FB17
50OHM
1
2
1
2
8
R43
1K
7
R44
1K
RP4A
10K
USBPWR_CONNE
USBPWR_CONND
USB_OC1# 16
USBE_VCC
USBD_VCC
FB15
50OHM
TPS2052
C334
0.1UF
+ C9
+ C34
C18
100uF
0.1UF
100uF
L12
4
16 USB_PP0
2
3
USBC_VCC
USBCUSBC+
90@100MHz
CR30
CR31
3
Triple
USB
2
2
3
1
1
1
16 USB_PN0
Clamping-Diode
Clamping-Diode
J9
1
2
3
4
VCC1
P#0
P0
GND1
TOP
PORT
USBD_VCC
USBUSB+
5
6
7
8
VCC2
P#1
P1
GND2
MIDDLE
PORT
USBE_VCC
9
10
11
12
VCC3
P#2
P2
GND3
BOTTOM
PORT
4
16 USB_PP1
2
3
1
1
90@100MHz
1
L11
16 USB_PN1
CR27
2
2
CR26
Clamping-Diode
Clamping-Diode
2
4
16 USB_PP3
2
3
CR28
+V3.3ALWAYS
0.1UF
+V5_ALWAYS
2
Clamping-Diode
Clamping-Diode
1
17,18,26
RP6A
10K
1
U11
EN1_B
EN2_B
1
2
3
4
GND
IN
EN1
EN2
OC1#
OUT1
OUT2
OC2#
8
7
6
5
USBPWR_CONNC
USB_OC0# 16
1
FB16
50OHM
1
2
USBC_VCC
OC2#
C337
0.1UF
TPS2052
A
7
R36
1K
RP6B
10K
8
R42
1K
CR29
2
C42
5,9,16,17,18,19,20,24,26,29,33,34,36,41
2
USBEUSBE+
90@100MHz
+V5_ALWAYS
3_stack_USB
2
17,18,26
13
14
15
16
1
L10
1
1
16 USB_PN3
GND4
GND5
GND6
GND7
B
C
+
C32
100uF
Title
Size
A
Date:
USB (1 of 2)
Document Number
Project:
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
of
25
E
47
A
B
C
D
E
DOCKING
UNIVERSAL SERIAL BUS
L7
4
4
1
4
DOCK_USBP5P 22
16 USB_PN5
2
3
DOCK_USBP5N 22
1
90@100MHz
1
16 USB_PP5
CR19
5,9,16,17,18,19,20,24,25,29,33,34,36,41
+V3.3ALWAYS
R49
10K
17,18,25
USB_OC2# 16
U14
C43
3
R47
R50
1K EN1
1K EN2
0.1UF
Clamping-Diode
Clamping-Diode
R46
10K
+V5_ALWAYS
1
2
3
4
2
2
CR18
GND
IN
EN1
EN2
OC1#
OUT1
OUT2
OC2#
8
7
6
5
USBPWR_CONNA
USBPWR_CONNB
1
FB18 50OHM
2
C333
USB_OC4# 16
0.1UF
TPS2052
3
C33 +
100uF
J8B
L14
1
4
16 USB_PP2
2
3
1
90@100MHz
FB3
1
16 USB_PN2
USBA_VCC
USBAUSBA+
CR33
CR32
1
50OHM
2
0.1UF
2
2
C335
VCC2
C22 +
100uF
1
2
3
4
VCC1
P#0
TOP
P0
GND10 PORT
5
6
7
8
VCC2 BOTTOM
P#1
PORT
P1
GND11
STACKED_RJ45_USB
Clamping-Diode
Clamping-Diode
L13
1
4
16 USB_PP4
2
3
USBBUSBB+
2
1
90@100MHz
1
2
16 USB_PN4
CR35
2
2
CR34
Clamping-Diode
Clamping-Diode
5,9,16,17,18,19,20,24,25,29,33,34,36,41
+V3.3ALWAYS
R455
10K
16 USB_OC5#
1
1
Title
Size
A
Date:
A
B
C
USB (2 of 2)
Project:
Document Number
855PM Platform
Monday, February 24, 2003 Sheet
26
D
Rev
of
E
47
A
B
C
D
E
+V3.3 7,9,15,17,20,24,29,32,34,36,40,41
4
4
+V3.3_LAN
R2
Bulk caps should be 4.7uF or higher.
0.01_1%
C5
C26
C25
4.7UF
4.7UF
0.1UF 0.1UF 0.1UF 0.1UF
C23
C2
C3
2
+V3.3_L_LAN
If LAN is enabled,
PM_LANPWROK waits for
PM_PWROK to go high and
stays high in S3.
R346
10K
LAN_RST
LAN_TXD2
LAN_TXD1
LAN_TXD0
LAN_RXD2
LAN_RXD1
LAN_RXD0
TP_LAN_ADV 41
30
28
29
TP_LAN_TOUT
26
LAN_TESTEN
21
3
LAN_TCK
Q2
BSS138
1
ADV10
ISOL_TCK
ISOL_TI
ISOL_EX
TOUT
TESTEN
R344
100
82562EM
2
15,29 PM_LANPWROK
JCLK
JRSTSYNC
JTXD2
JTXD1
JTXD0
JRXD2
JRXD1
JRXD0
Platform LAN
Connect
C7
0.1UF
4.7UF
+V3.3_LAN
J8A
No Stuff
LAN_TDP
LAN_TDN
R7
C1
TDP
TDN
10
11
RDP
RDN
15
16
TDC
NO_STUFF_10PF
Need 124 Ohm 1%
R6
120
100_1%
LAN_RDP
LAN_RDN
R4
619_1%
R3
549_1%
5 LAN_RB100
4 LAN_RB10
ACTLED
SPDLED
LILED
32
31
27
LAN_ACTLED#
LAN_SPDLED#
LAN_LILED#
X2
X1
47
46
LAN_X2
LAN_X1
C24
TDP
TDN
13
12
TDC1
TDC2
11
14
RDP
RDN
LED_PWR
SPEED LED
ACT_LED
LINK_LED
GRN
YLW
RXC
15
GND1
GND2
GND3
GND4
GND5
GND6
GND7
GND8
GND9
28
27
26
25
24
23
22
21
16
3
STACKED_RJ45_USB
Magnetics and
LED resistors
are integrated
into RJ-45
25MHZ
Chassis GND
(should cover part
of magnetics)
C12
22PF
2
9
10
17
18
19
20
Y1
J7
1
Optional cap: C1 value
6pF - 12pF if needed for
magnetics
U2
RBIAS100
RBIAS10
VSS2
VSS3
VSS4
VSS5
VSS1
VSSP_2
VSSP_1
VSSA_2
VSSA2
VSSR1
VSSR2
15
15
15
15
15
15
15
+V3.3_LAN
3
39
42
45
44
43
37
35
34
C4
8
13
18
24
48
33
38
3
6
20
22
15 LAN_JCLK
VCC1
VCC2
VCCP_2
VCCP_1
VCCA_1
VCCA2
VCCT_1
VCCT_2
VCCT_3
VCCT_4
VCCR1
VCCR2
1
25
36
40
2
7
9
12
14
17
19
23
4.7UH
Layout note:
Transmit/Receive pairs
need to be 50 ohms
Layout note:
Place 100 Ohm resistor
close to 82562EM
L1
1
22PF
NO_STUFF
82562EM Testpoint Header
2
2
1
1
Title
Size
A
Date:
A
B
C
LAN Interface (82562EM)
Project:
Document Number
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
27
of
E
47
A
B
C
D
E
4
4
5,9,10,14,15,17,18,20,23,30,31,32,33,36,37,38,41,42
+V3.3S
+V3.3S_FWH
R281
0.01_1%
U44
15 FWH_INIT#
6,15,23,34,42 PCI_RST#
R488
PCI_RST#_D
100
37
12
9
14 CLK_FWHPCI
R481
R506
R493
R495
R499
100
100
100
100
100
INIT#
RST#
CLK
FGPIO4
FGPIO3
FGPIO2
FGPIO1
FGPIO0
7
15
16
17
18
FGPI4
FGPI3
FGPI2
FGPI1
FGPI0
TP_FWH_ID3
TP_FWH_ID2
TP_FWH_ID1
TP_FWH_ID0
21
22
23
24
ID3
ID2
ID1
ID0
TP_FWH_RSVD2
TP_FWH_RSVD1
TP_FWH_RSVD5
TP_FWH_RSVD4
TP_FWH_RSVD3
32
33
34
35
36
RSVD2
RSVD1
RSVD5
RSVD4
RSVD3
29
30
40
GND2
GND1
GNDA
3
FWH
VPP
VCC2
VCC1
VCCA
11
10
31
39
TBL#
WP#
20
19
FWH4
FWH3
FWH2
FWH1
FWH0
38
28
27
26
25
IC
NC1
NC2
NC3
NC4
NC5
NC6
NC7
NC8
2
1
3
4
5
6
8
13
14
C507
0.1UF
C289
C505
0.1UF
4.7UF
TBL# R507
WP# R505
100
100
FWH_TBL# 16,34
FWH_WP# 16,34
LPC_FRAME# 16,29,30,31,34
LPC_AD3 16,29,30,31,34
LPC_AD2 16,29,30,31,34
LPC_AD1 16,29,30,31,34
LPC_AD0 16,29,30,31,34
IC
3
TP_FWH_NC1
TP_FWH_NC2
TP_FWH_NC3
TP_FWH_NC4
TP_FWH_NC5
TP_FWH_NC6
TP_FWH_NC7
TP_FWH_NC8
R479
10K
FWH SKT
2
2
1
1
FWH sits in the
FWH_TSOP_Socket,
Not on the board
A
B
C
Title
Size
A
Date:
FWH
Project:
855PM Platform
Monday, February 24, 2003
D
Document Number
Sheet
Rev
of
28
E
47
B
+V3.3ALWAYS
C
D
R10
J16
C19
C339
C340
C341
C338
22UF
0.1UF
0.1UF
0.1UF
0.1UF
0.01_1%
1
+V3.3ALWAYS 5,9,16,17,18,19,20,24,25,26,33,34,36,41
KSC Testpoint Header
Y2
Program
+V3.3ALWAYS_KBC 30
C77
R34
240
RP7D
10K
U13
KBC_GP_DATA 33
KBC_GP_CLK 33
PA3/CIN11/KIN11#/PS2AD
PA2/CIN10/KIN10#/PS2AC
30
31
KBC_MOUSE_DATA 33
KBC_MOUSE_CLK 33
5
6
MD1
MD0
SMC_XTAL
SMC_EXTAL
2
3
XTAL
EXTAL
PA5/CIN13/KIN13#/PS2BD
PA4/CIN12/KIN12#/PS2BC
P95/CS1#
P94/IOW#
P93/IOR#
20
21
18
19
22
KBC_CAPSLOCK
KBC_SCROLLOCK
KBC_NUMLOCK
SMC_RES#
SMC_STBY#
1
8
7
RES#
STBY#
NMI
P60/FTCI/CIN0/KIN0#
P61/FTOA/CIN1/KIN1#
P62/FTIA/CIN2/KIN2#/TMIY
P63/FTIB/CIN3/KIN3#
P64/FTIC/CIN4/KIN4#
P65/FTID/CIN5/KIN5#
P66/FTOB/CIN6/KIN6#/IRQ6#
P67/CIN7/KIN7#/IRQ7#
26
27
28
29
32
33
34
35
KBC_SCANIN0
KBC_SCANIN1
KBC_SCANIN2
KBC_SCANIN3
KBC_SCANIN4
KBC_SCANIN5
KBC_SCANIN6
KBC_SCANIN7
P27/PW15
P26/PW14
P25/PW13
P24/PW12
P23/PW11
P22/PW10
P21/PW9
P20/PW8
P17/PW7
P16/PW6
P15/PW5
P14/PW4
P13/PW3
P12/PW2
P11/PW1
P10/PW0
60
61
62
63
64
65
66
67
72
73
74
75
76
77
78
79
KBC_SCANOUT15
KBC_SCANOUT14
KBC_SCANOUT13
KBC_SCANOUT12
KBC_SCANOUT11
KBC_SCANOUT10
KBC_SCANOUT9
KBC_SCANOUT8
KBC_SCANOUT7
KBC_SCANOUT6
KBC_SCANOUT5
KBC_SCANOUT4
KBC_SCANOUT3
KBC_SCANOUT2
KBC_SCANOUT1
KBC_SCANOUT0
P30/HDB0/LAD0
P31/HDB1/LAD1
P32/HDB2/LAD2
P33/HDB3/LAD3
P34/HDB4/LFRAME#
P35/HDB5/LRESET#
P36/HDB6/LCLK
P37/HDB7/SERIRQ
P82/CLKRUN#
P83/LPCPD#
82
83
84
85
86
87
88
89
95
96
P85/IRQ4#
P86/IRQ5#/SCL1
P42/TMRI0/SDA1
98
99
51
VSS1
VSS2
VSS3
VSS4
AVSS
15
70
71
92
46
R18
16,18,22,34,36 PM_PWROK
R45 VR_SHUTDOWN_R
TP_NMI_GATE#
0
0
33,34,41
33,34,41
14,16,22,34,40,41
P91/IRQ1# 33,34,41
+V3.3ALWAYS 5,9,16,17,18,19,20,24,25,26,33,34,36,41
SW2
2
7 LIDON
1
RP1B 10K
2
3
SPDT_SLIDE
LID
SWITCH
SMB_SB_CLK
SMB_SB_DATA
PM_SLP_S3#
SMB_SB_ALRT#
34,41 SMC_ONOFF#
SMC_LID
VIRTUAL_BATTERY
16,34,41 PM_SLP_S4#
34,41 AC_PRESENT#
21,33,34 DOCK_INTR#
BT_WAKE
TP_KSC_P76
KBC_DISABLE#
5,9,16,17,18,19,20,24,25,26,33,34,36,41
BT_ON
R5 10K
2
VBATTON 1
SW1
2
3
SPDT_SLIDE
+V3.3ALWAYS_KBC 30
4
VIRTUAL
BATTERY
RP1D
10K
15,27
16,34
34,37
34,35
16,18,22,34,36
16,18,34
5,16,18,34
34,41
15,34
34
2
5
5,34
5,34
16,33,34
16,31,33,34
16,33,34
33,34
1
J1
PM_LANPWROK
PM_PWRBTN#
VR_ON
FAN_ON
PM_PWROK
PM_RSMRST#
PM_THRM#
SMC_SHUTDOWN
H_RCIN#
SMC_RSTGATE#
SMB_THRM_CLK
SMB_THRM_DATA
SMC_RUNTIME_SCI#
SMC_EXTSMI#
SMC_WAKE_SCI#
KBC_A20GATE
34 BAT_SUSPEND
16,33,34 PM_BATLOW#
+V3.3ALWAYS 5,9,16,17,18,19,20,24,25,26,33,34,36,41
+V3.3ALWAYS_KBC 30
BT_DETACH
RP9A
10K
1
RP9B
10K
RP9C
10K
Program
P70/AN0
P71/AN1
P72/AN2
P73/AN3
P74/AN4
P75/AN5
P76/AN6/DA0
P77/AN7/DA1
PA1/CIN9/KIN9#
PA0/CIN8/KIN8#
P40/TMCI0
P41/TMO0
P43/TMCI1/HIRQ11
P44/TMO1/HIRQ1
P45/TMR11/HIRQ12
P46/PWX0
P47/PWX1
PB5/WUE5#
PB4/WUE4#
80
81
90
91
93
94
PB3/CS4#/WUE3#
PB2/CS3#/WUE2#
PB1/HIRQ4/WUE1#/LSCI
PB0/HIRQ3/WUE0#/LSMI#
P80/HA0/PME#
P81/CS2#/GA20
57
58
PB7/WUE7#
PB6/WUE6#
97
P84/IRQ3#
100
H8S/2149F-Z
RESO#
SMC_PROG_RST#
SMC_MD
2
4
6
8
10
12
14
CON14_RECEPT
A
Q11
BSS138
3
1
KBC_SCANIN[7:0]
Q6
BSS138
33
1
Q5
BSS138
Bluetooth
Sideband
+V3.3ALWAYS
KBC_SCANOUT[15:0] 33
LPC_AD0 16,28,30,31,34
LPC_AD1 16,28,30,31,34
LPC_AD2 16,28,30,31,34
LPC_AD3 16,28,30,31,34
LPC_FRAME# 16,28,30,31,34
5,9,16,17,18,19,20,24,25,26,33,34,36,41
J14
BT_WAKE
1
BT_ON
2
BT_DETACH
3
SMB_SB_CLK
4
SMB_SB_DATA 5
6
7
2
8
8Pin_HDR
CLK_SMCPCI 14
INT_SERIRQ 15,19,20,21,31,34
PM_CLKRUN# 16,18,31,34
PM_SUS_STAT# 9,16,31,34
9,15,19,20,21,30,31,34
BUF_PCI_RST#
SMB_SC_INT# 34
SCL1
SDA1
Measurement Point
J13
+V3.3 7,9,15,17,20,24,27,32,34,36,40,41
RP9D
10K
3
2
Q20
BSS138
9,19,20,34 PCI_GATED_RST#
1
SMC_RSTGATE#
GATE OFF PCIRST# during S3
6
1
3
5
7
9
11
13
7
8
38
39
40
41
42
43
44
45
47
48
49
50
52
53
54
55
56
68
69
KSC Keyboard & System
Management Controller
J25
BT_DETACH
P51/RxD0
P50/TxD0
P52/SCK0/SCL0
P97/SDA0
P96/0/EXCL
P92/IRQ0#
P91/IRQ1#
P90/IRQ2#/ADTRG#
3
2
1
TP_KSC_RES0
13
14
12
16
17
23
24
25
1
2
36 VR_SHUT_DOWN#
24,30 SMC_INITCLK
KBC_KB_DATA 33
KBC_KB_CLK 33
DS1
GREEN
2
NO_STUFF_10K
R72
3
3 LED_CAPS
1
3
CON3_HDR
DS3
GREEN
2
SMC_MD
SMC_MD
2
3
1
2
DS4
GREEN
4
5
10
11
RST_HDR#1
5,9,16,17,18,19,20,24,25,26,33,34,36,41
+V3.3ALWAYS
PA7/CIN15/KIN15#/PS2CD
PA6/CIN14/KIN14/PS2CC
5
4
74AHC1G08
+V3.3ALWAYS
VCC
VCL
VCCB
AVREF
AVCC
2
SMC_PROG_RST#
59
9
4
36
37
J12
1
30 SMC_RST#
6
U6
R14
240
1
5
+V3.3ALWAYS_KBC 30
R25
240
+V3.3ALWAYS_KBC 30
2 LEDD3
RP7C
10K
P91/IRQ1#
4
2
1
18pF
30 +V3.3ALWAYS_KBC
LED_NUM
10MHZ
18pF
J1
No Shunt (Default)
Shunt
3
C79
1
3
NO_STUFF_10K
J21
Decode KBC Addresses
Enable 60h & 64h
Disable
2 LEDD2
R19
4
4
P90-P92 needs to be at VCC for boot mode
programming. They are already pulled up in
the design. MD0, MD1 needs to be at Vss.
Jumper for J21 needs to be populated.
System needs to supply +V3ALWAYS to
flash connector.
J12
1-2 (Default)
2-3
1
Measurement Point
KSC
Enable
Disable
LED_SCROLL
2
VR_SHUTDOWN_R
E
Boot Mode
Programming Straps
30 +V3.3ALWAYS_KBC
3
5,9,16,17,18,19,20,24,25,26,33,34,36,41
2 LEDD1
A
J4
TP_KSC_RES0 1
Note: for flash progamming, must use
TX1 and RX1, which are pin97 and pin98.
B
TP_NMI_GATE# 3
Title
2 TP_KSC_P76
NO_STUFF_CON3_HDR
C
Size
A
Date:
System Management and Keyboard Controller
Project:
855PM Platform
Monday, February 24, 2003
D
Document Number
Sheet
Rev
29
of
E
47
A
B
C
D
E
Circuitry provides an interrupt to the SMC
every 1s while in suspend (this allows
the SMC to complete housekeeping
functions while suspended)
29 +V3.3ALWAYS_KBC
1 Hz Clock J6
Enable No Shunt
29 +V3.3ALWAYS_KBC
4
14
R9
0
VCCMAX809
Disable Shunt
R15
1M
SMC_INIT_CLK1 3
14
4
7
SMC_INIT_CLK2 5
U7B
74HC04
C27
1
2
7
2
U7A
74HC04
Q10
BSS138
1
0
INVD1
11
10
U7E
74HC04
7
SMC_RST# 29
1
16 KSC_VPPEN#
3
29 +V3.3ALWAYS_KBC
14
2
3
R24
NOTE: Stuff J6 for SMC Programming
Q4
BSS138
1
MAX809
SMC_RST
1
R8
4.7K
29 +V3.3ALWAYS_KBC
14
3
SMC_RST#_D
2
2
R30
100K
J6
14
RST#
7
SMC_INITCLK 24,29
SMC_INIT_CLK4
3
Q1
8
U7D
74HC04
4.7uF
0.1UF
VCC
3
SMC_INIT_CLK3 9
U7C
74HC04
29 +V3.3ALWAYS_KBC
C17
GND
6
7
4
14
R17
0
INVD2
13
12
U7F
74HC04
7
SMC SUSPEND TIMER
PORT 80 DISPLAY
5,9,10,14,15,17,18,20,23,28,31,32,33,36,37,38,41,42
5,9,10,14,15,17,18,20,23,28,31,32,33,36,37,38,41,42
CR10
LPC_FRAME# 16,28,29,31,34
+V3.3S
LED1_INPUT1
LED1_INPUT2
LED1_INPUT3
LED1_INPUT4
LED1_INPUT5
LED1_INPUT6
LED1_INPUT7
U29
2
14 CLK_PCI_PORT80
9,15,19,20,21,29,31,34 BUF_PCI_RST#
OE#_PORT80
9
17
29
41
VCC1
VCC2
VCC3
VCC4
37
39
GCLK
GCLR#
38
40
OE#1
OE#2
IO32
IO31
IO30
IO29
IO28
IO27
IO26
IO25
IO24
IO23
IO22
IO21
IO20
IO19
IO18
IO17
IO16
IO15
IO14
IO13
IO12
IO11
IO10
IO9
IO8
IO7
IO6
IO5
IO4
IO3
IO2
IO1
R403
100
38,41,42
1
+V3.3S
C438
0.1UF
C426
0.1UF
C450
0.1UF
4
16
24
36
GND1
GND2
GND3
GND4
44
43
42
35
34
33
32
31
30
28
27
26
25
23
22
21
20
19
18
15
14
13
12
11
10
8
7
6
5
3
2
1
5
6
7
5
7
6
8
LED1_INPUT1_R
LED1_INPUT2_R
LED1_INPUT3_R
LED1_INPUT4_R
LED1_INPUT5_R
LED1_INPUT6_R
LED1_INPUT7_R
1
10
8
5
4
2
3
7
A
B
C
D
E
F
G
DP
6
9
AN1
AN2
2
LEFT
5,9,10,14,15,17,18,20,23,28,31,32,33,36,37,38,41,42
CR9
LED2_INPUT1
LED2_INPUT2
LED2_INPUT3
LED2_INPUT4
LED2_INPUT5
LED2_INPUT6
LED2_INPUT7
RP13D4
RP13C3
RP13A1
RP14C3
RP14B2
RP14D4
RP13B2
150
150
150
150
150
150
150
5
6
8
6
7
5
7
LED2_INPUT1_R
LED2_INPUT2_R
LED2_INPUT3_R
LED2_INPUT4_R
LED2_INPUT5_R
LED2_INPUT6_R
LED2_INPUT7_R
1
10
8
5
4
2
3
7
A
B
C
D
E
F
G
DP
AN1
AN2
+V3.3S
6
9
7-SEG-LED-DISPLAY
LPC_AD3
LPC_AD2
LPC_AD1
LPC_AD0
16,28,29,31,34
16,28,29,31,34
16,28,29,31,34
16,28,29,31,34
1
RIGHT
Title
Size
A
Date:
B
150
150
150
150
150
150
150
7-SEG-LED-DISPLAY
EPM7032AE
A
RP12D4
RP12C3
RP12B2
RP11D4
RP11B2
RP11C3
RP11A1
+V3.3S
C
SMC Suspend Timer and Port 80 LEDs
Document Number
Project:
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
of
30
E
47
A
B
C
D
E
BUF_PCI_RST# 9,15,19,20,21,29,30,34
+V5S 9,17,20,21,24,32,33,35,36,37,38,41,42
PPT_PNF# 32
J52
SIO
Enable
Disable
+V3.3S_SIO
1
+V3.3S_SIO
RP35A
8 10K
1
R185
R180
100
100
RP20C
RP20B
RP20A
RP17D
SER_DCDA# 32
SER_DSRA# 32
SER_SINA 32
SER_RTSA# 32
SER_SOUTA 32
SER_CTSA# 32
SER_DTRA# 32
SER_RIA# 32
XCNF1/XWR# RP35C 6
R143
RP19B
RP19C
RP19D
RP21A
4
7
6
5
8
2
3
4
1
RP21B
RP21C
RP21D
RP19A
2
3
4
1
RP15B 7
4.7K
1
C224
330PF
2
3
2
1
4
33
33
33
33
6
7
8
5
PPT_PD7
PPT_PD6
PPT_PD5
PPT_PD4
32
32
32
32
RP17C 3
RP17B 2
RP17A 1
R411
33
33
33
6
7
8
33
PPT_PD3
PPT_PD2
PPT_PD1
PPT_PD0
32
32
32
32
3
1
1
C245 C244 C226 C454
1
680PF 680PF 330PF 330PF C457
2
2
330PF
2
3 10K
10K
1
1
1
1
1
C458 C236 C239 C466 C240
330PF 330PF 330PF 330PF 330PF
2
2
2
2
2
+V3.3S 5,9,10,14,15,17,18,20,23,28,30,32,33,36,37,38,41,42
2
R531
330
R530
330
R529
330
R528
330
R527
330
VID5_LED
VID4_LED
VID3_LED
VID2_LED
VID1_LED
VID0_LED
DS10
GREEN
DS11
GREEN
DS12
GREEN
DS13
GREEN
DS14
GREEN
2
2
2
1
1
DS9
GREEN
R526
330
1
65
2
NC
RP15A 8
4.7K
85
84
83
82
5
1
GPIO30
GPIO31
GPIO32
GPIO33
GPIO34
R150
4.7K
87
86
RP15C 6
4.7K
GPIO26
GPIO27
3
95
94
93
92
91
BUSY/WAIT#
ACK#
PD7
PD6
PD5
PD4
PD3
PD2
PD1
PD0
1
C225
PPT_SLCT 32
PPT_PE 32
330PF
PPT_BUSY/WAIT# 32
2
PPT_ACK# 32
2
GPIO10
GPIO11
GPIO12
GPIO13
GPIO14
GPIO15
GPIO16
GPIO17
GPIO20
GPIO21
GPIO22
GPIO23
GPIO24
33 ohm can be 5%
1
81
80
79
78
77
76
75
74
GPIOs
XCNF1/XWR#
XCNF2
4
90
33
33
2
Serial
Port
FDC
2
GPIO0
GPIO1
GPIO2
GPIO3
GPIO4
GPIO5
GPIO6
GPIO7
55
56
57
58
59
60
61
62
R145
R144
AFD#/DSTRB#
STB#/WRITE#
1
Parallel
Port
IR
Straps
3
2
1
100
99
98
97
96
DCD1#
DSR1#
SIN1
RTS1#
SOUT1/XCNF0
CTS1#
DTR1#
RI1#
RP15D 5
4.7K
DSKCHG#
HDSEL#
RDATA#
WP#
TRK0#
WGATE#
WDATA#
STEP#
DIR#
DR0#
MTR0#
INDEX#
DENSEL
DRATE0
DR1#
MTR1#
32 FLP_DSKCHG#
32 FLP_HDSEL#
32 FLP_RDATA#
32 FLP_WP#
32 FLP_TRK0#
32 FLP_WGATE#
32 FLP_WDATA#
32 FLP_STEP#
32 FLP_DIR#
32 FLP_DR0#
32 FLP_MTR0#
32 FLP_INDEX#
32 FLP_DENSEL#
32 FLP_DRATE0
35
36
37
40
41
42
43
44
45
46
48
50
52
4
21
22
23
24
25
26
27
28
29
30
31
32
33
34
72
73
32 IR_TXD
3
PNF
SLCT
PE
BUSY/WAIT#
ACK#
PD7
PD6
PD5
PD4
PD3
PD2
PD1
PD0
RP22C 6
4.7K
IRRX1
IRRX2_IRSL0
IRSL1
IRSL2A/DR1B/XIORDB
IRSL3/PWUREQ
IRTX
IR_RXD
IR_SEL
IR_MD0
IR_MD1
3
69
68
67
71
66
70
32
32
32
32
Clock
PPT_SLIN#/ASTRB# 32
PPT_INIT# 32
PPT_ERR# 32
PPT_AFD#/DSTRB# 32
PPT_STB#/WRITE# 32
2
CLKIN
47
49
51
53
54
1
20
14 CLK_SIO14
SLIN#/ASTRB#
INIT#
ERR#
AFD#/DSTRB#
STB#/WRITE#
RP22D 5
4.7K
SERIRQ
SMI#
LPCPD#
CLKRUN#
4
10
19
7
6
14
39
63
88
13
38
64
89
RP22A 8
4.7K
RP22B 7
4.7K
15,19,20,21,29,34 INT_SERIRQ
16,29,33,34 SMC_EXTSMI#
9,16,29,34 PM_SUS_STAT#
16,18,29,34 PM_CLKRUN#
VDD1
VDD2
VDD3
VDD4
VSS5
VSS6
VSS7
VSS8
2
LAD0
LAD1
LAD2
LAD3
LCLK
LDRQ#
LFRAME#
LRESET#
Bus
Interface
15
16
17
18
8
11
12
9
1
+V5S_DIODE
16,28,29,30,34 LPC_AD0
16,28,29,30,34 LPC_AD1
16,28,29,30,34 LPC_AD2
16,28,29,30,34 LPC_AD3
14 CLK_SIOPCI
16,34 LPC_DRQ#0
16,28,29,30,34 LPC_FRAME#
PWR &
GND
U31
4
3
CR21
BAR43
1K
1K
1K
1K
CON3_HDR
J52
1-2 (Default)
2-3
7
6
5
8
2 SIO_RST#
3
1K
1K
1K
1K
1
PC87393
SIO_LED_VID4
SIO_LED_VID3
SIO_LED_VID2
SIO_LED_VID1
SIO_LED_VID0
SIO_LED_VID5
+V3.3S 5,9,10,14,15,17,18,20,23,28,30,32,33,36,37,38,41,42
+V3.3S_SIO
1
42
42
42
42
42
42
IDE_SPWR_EN# 24,34
R220
0.01_1%
C471
C467
C221
0.1UF
0.1UF
22UF
1
Title
Size
A
Date:
A
B
C
Super I/O Controller
Document Number
Project:
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
of
31
E
47
A
B
7
9
11
13
15
17
19
21
23
25
27
29
31
33
RP53D 4
1K
RP53C 3
1K
RP52C 3
1K
5
6
6
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
RP52A 1
1K
1
3
8
J80
4
RP53A 1
1K
FLOPPY CONNECTOR
D
+V5S
8
9,17,20,21,24,31,33,35,36,37,38,41,42
C
E
J10
6
5
8
7
60OHM@100MHZ
FB7C
PPT_L_PE
FB7D
PPT_L_BUSY/WAIT#
FB10A
PPT_L_ACK#
FB10B
PPT_L_PD7
3
4
2
3
6
5
7
6
60OHM@100MHZ
FB10C
FB10D
FB6B
FB6C
1
4
1
2
8
5
8
7
60OHM@100MHZ
FB6A
PPT_L_SLIN#
FB6D
PPT_L_PD2
FB4A
PPT_L_INIT#
FB4B
PPT_L_PD1
3
4
1
2
6
5
8
7
60OHM@100MHZ
FB4C
PPT_L_ERR#
FB4D
PPT_L_PD0
FB5A
PPT_L_AFD#/DSTRB#
FB5B
PPT_L_STB#/WRITE#
3
4
1
2
31 PPT_PE
31 PPT_BUSY/WAIT#
31 PPT_ACK#
31 PPT_PD7
PARALLEL PORT
60OHM@100MHZ
PPT_L_PNF#
8 FB7A
PPT_L_SLCT
7 FB7B
1
2
31 PPT_PNF#
31 PPT_SLCT
13
25
12
24
11
23
10
22
9
21
8
20
7
19
6
18
5
17
4
16
3
15
2
14
1
FLP_DENSEL# 31
FLP_DRATE0 31
FLP_INDEX# 31
FLP_MTR0# 31
PPT_L_PD6
FLP_DR0# 31
31
31
31
31
FLP_DIR# 31
FLP_STEP# 31
FLP_WDATA# 31
FLP_WGATE# 31
FLP_TRK0# 31
FLP_WP# 31
FLP_RDATA# 31
FLP_HDSEL# 31
FLP_DSKCHG# 31
PPT_PD6
PPT_PD5
PPT_PD4
PPT_PD3
31 PPT_SLIN#/ASTRB#
31 PPT_PD2
31 PPT_INIT#
31 PPT_PD1
17x2_HDR
3
31 PPT_ERR#
31 PPT_PD0
31 PPT_AFD#/DSTRB#
31 PPT_STB#/WRITE#
5,9,10,14,15,17,18,20,23,28,30,31,33,36,37,38,41,42
PPT_L_PD5
PPT_L_PD4
PPT_L_PD3
4
26
GND0
27
GND1
28
GND2
PARALLEL
3
INFRARED PORT
+V3.3S
+V3.3S_IR
+V3.3S 5,9,10,14,15,17,18,20,23,28,30,31,33,36,37,38,41,42
R341
NO_STUFF_2.2
+V3.3 7,9,15,17,20,24,27,29,34,36,40,41
31 IR_TXD
31 IR_RXD
3
Q43
BSS138
1
SERBUF_C1- 24
C16
0.1UF
2
16 SER_EN
C1+
26
27
SERBUF_V+
C15
1
2
31 SER_CTSA#
31 SER_RIA#
31 SER_SINA
31 SER_DSRA#
31 SER_DCDA#
20
19
18
17
16
15
31 SER_DTRA#
31 SER_SOUTA
31 SER_RTSA#
14
13
12
T1IN
T2IN
T3IN
23
22
21
FORCEON
FORCEOFF#
INVALID#
SER_ON
TP_INVALID
2
NO_STUFF_0.1UF NO_STUFF_10UF
C2+
SER_RIA
11
NO_STUFF_HSDL-3600#017
C332
0.1UF
C1-
SERBUF_C2-
1K
V+
C331
SERBUF_C2+
R1
1
SERBUF_C1+ 28
31 IR_MD1
31 IR_MD0
31 IR_SEL
VCC
C14
0.1UF
0.1UF
U3
V-
SERBUF_V-
3
C13
Caps must be placed
as close as possible to
pins 1,2
0.1UF
C2R2OUTB
R1OUT
R2OUT
R3OUT
R4OUT
R5OUT
R1IN
R2IN
R3IN
R4IN
R5IN
T1OUT
T2OUT
T3OUT
GND
4
5
6
7
8
SERIAL PORT
SERBUF_CTSA
SERBUF_RIA
SERBUF_SINA#
SERBUF_DSRA
SERBUF_DCDA
3
4
3
1
9 SERBUF_DTRA
10 SERBUF_SOUTA#
11 SERBUF_RTSA
25
2
4
1
2
6
5
6
8
7
5
8
7
60OHM@100MHZ
FB5C
SERPRT_DCDA
FB5D
SERPRT_DSRA
FB8C
SERPRT_SINA#
FB8A
SERPRT_RTSA
60OHM@100MHZ
SERPRT_SOUTA#
FB8B
SERPRT_CTSA
FB8D
SERPRT_DTRA
FB9A
SERPRT_RIA
FB9B
J5
1
6
2
7
3
8
4
9
5
11
GND0
16,18,34 PM_RI#
C336
22UF
LEDA
TXD
RXD
GND
NC
MOD1
MOD0
FIR_SEL
AGND
VDD
MNT
GND1
2
C6
U1
10
9
8
7
6
5
4
3
2
1
10
1
SERIAL
MAX3243
R2OUTB is enabled even in suspend.
SER_RIA# is routed to allow the system to
wake up in Suspend To RAM.
R345
1K
Size
A
Date:
Note: FORCEOFF# overrides FORCEON.
A
B
Title
C
Floppy, Parallel, Serial, and IR Ports
Document Number
Project:
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
of
32
E
47
A
B
C
D
9,17,20,21,24,31,32,35,36,37,38,41,42
E
+V5S
KBC_SCANOUT[15:0] 29
CBTD has integrated
diode for 5V to 3.3V
voltage translation
J32
4
KBC_SCANOUT0
KBC_SCANOUT2
KBC_SCANOUT4
KBC_SCANOUT6
KBC_SCANOUT8
KBC_SCANOUT10
KBC_SCANOUT12
KBC_SCANOUT14
KBC_SCANIN0
KBC_SCANIN2
KBC_SCANIN4
KBC_SCANIN6
1
3
5
7
9
11
13
15
2
4
6
8
10
12
14
16
17
19
21
23
18
20
22
24
KBC_SCANOUT1
KBC_SCANOUT3
KBC_SCANOUT5
KBC_SCANOUT7
KBC_SCANOUT9
KBC_SCANOUT11
KBC_SCANOUT13
KBC_SCANOUT15
U10
29 KBC_GP_DATA
29 KBC_GP_CLK
29 KBC_MOUSE_DATA
29 KBC_MOUSE_CLK
29 KBC_KB_DATA
KBC_SCANIN1
KBC_SCANIN3
KBC_SCANIN5
KBC_SCANIN7
29 KBC_KB_CLK
15 H_A20GATE
NO_STUFF_24Pin_ZIF-HDR
OE#_PS2
Scan Matrix Key Board
KBC_SCANIN[7:0]
9,17,20,21,24,31,32,35,36,37,38,41,42
C21
0.1UF
3
4
7
8
11
1A1
1A2
1A3
1A4
1A5
14
17
18
21
22
2A1
2A2
2A3
2A4
2A5
1
13
1OE#
2OE#
29
4
VCC
24
1B1
1B2
1B3
1B4
1B5
2
5
6
9
10
GP_DATA
GP_CLK
MOUSE_DATA
MOUSE_CLK
KBD_DATA
2B1
2B2
2B3
2B4
2B5
15
16
19
20
23
KBD_CLK
GND
12
KBC_A20GATE 29,34
5,9,10,14,15,17,18,20,23,28,30,31,32,36,37,38,41,42
3 RP48C 6
8.2K
Bus-Switch-74CBT3384
R16
100
+V5S
9,17,20,21,24,31,32,35,36,37,38,41,42
+V5S
2
1
5,9,16,17,18,19,20,24,25,26,29,34,36,41
RP5A
4.7K
RP35D
RP56A
RP56B
RP56D
RP69A
RP49B
RP49C
RT1
1.1A
3
6
FB9C
60OHM@100MHZ
6
9,17,20,21,24,31,32,35,36,37,38,41,42
CP1C
47PF
+V5S
2
3
PS2_PWR_L +1
8
GP_CLK
+V3.3ALWAYS
RP2B
4.7K
4
1
2
4
1
2
3
R12
FB2
60ohm@100MHz
1
2
1
FB12
31Ohm@100MHz
L_GPDATA
10K
10K
10K
10K
10K
10K
10K
5
8
7
5
8
7
6
3
SMC_EXTSMI# 16,29,31,34
SMC_RUNTIME_SCI# 16,29,34
SMC_WAKE_SCI# 16,29,34
PM_BATLOW# 16,29,34
SMB_SB_DATA 29,34,41
SMB_SB_CLK 29,34,41
SMB_SB_ALRT# 29,34,41
10K
DOCK_INTR# 21,29,34
7
3
+V3.3S
GP_DATA
2
9,17,20,21,24,31,32,35,36,37,38,41,42
+V5S
C11
3
+V5S 9,17,20,21,24,31,32,35,36,37,38,41,42
L_PS2_PWR
4
47pF
RP2C
4.7K
RP2D
4.7K
KBD_CLK
J2
1
8
L_GPCLK
6 4 2
L_KBD_CLK
5
1
13
14
15
CP1A
47PF
FB1
60ohm@100MHz
L_KBD_DATA1
2
2
6
FB13
60ohm@100MHz
1
2
5
2
KBD_DATA
C10
3
47pF
16
17
9,17,20,21,24,31,32,35,36,37,38,41,42
10
12
8
7
11
MOUSE_CLK
CP1B
47PF
+V5S
3
FB11
60ohm@100MHz
2
4
7
5
B
C
0.1UF
1
MOUSE_DATA
2
CP1D
47PF
Title
Size
A
Date:
A
C30
22UF
If a PS/2 "breakout" connector is used,the keyboard PS/2
connector can be used for both a PS/2 keyboard and a
second PS/2 mouse. Otherwise, the keyboard PS/2
connector will only support a PS/2 keyboard.
RP5C
4.7K
1
C29
6
FB14
60ohm@100MHz
1
2
8
1
DUAL_PS2
L_MOUSE_DATA
RP2A
4.7K
9,17,20,21,24,31,32,35,36,37,38,41,42
9
L_MOUSE_CLK
+V5S
1
9,17,20,21,24,31,32,35,36,37,38,41,42
+V5S
Keyboard and Mouse Connectors
Project:
Document Number
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
33
of
E
47
A
B
9,14,18,20,24,41 +V12S
C
D
E
LPC POWERED ON SUSPEND RAIL FOR ADD-IN H8 CARD
+V3.3_LPCSLOT
J69
16,17,18,19,21 +V3.3S_ICH
+V3.3_LPCSLOT
LPC Debug Slot
16 PM_SUS_CLK
9,16,17,18,19,20,24,25,26,29,33,36,41
+V3.3ALWAYS
15,29 H_RCIN#
29,33 KBC_A20GATE
16,29,31,33 SMC_EXTSMI#
12V1
SUSCLK
GND1
LREQ
VCC3_1
LCNTL0
GND3
LDC
LD5
GND4
LD3
LD1
GND6
3V_STBY
LPS
KBRESTE#
A20GATE#
GND8
LSMI#
+V5_LPCSLOT
3
12V2
NEG_12V
GND2
BP_CLK
VCC3_2
LCNTL1
GND5
LD6
LD4
GND7
LD2
LD0
VCC5_2
SCLK
GND10
SERIRQ
CLKRUN#
GND12
LINK_ON
A1
A2
A3
A4
A5
A6
A7
A8
A9
A10
A11
A12
A13
A14
A15
A16
A17
A18
A19
8
4
15,18
SMB_ALERT#
3,15
H_NMI
3,15
H_SMI#
1
2
3
4
16 ICH_GPIO7
16 ICH_GPIO42
16 ICH_GPIO43
J97
CON4_HDR
B20
B21
B22
B23
B24
B25
B26
B27
B28
B29
B30
16,28,29,30,31 LPC_AD2
16,28,29,30,31 LPC_AD0
14 CLK_LPC14
H_INIT# 3,15
H_INTR 3,15
PCI_RST# 6,15,23,28,42
H_STPCLK# 3,15
H_CPUSLP# 3,15
1
2
3
4
5
6
3,6,15 H_DPSLP#
16,36,38 PM_DPRSLPVR
R331
4
J70
14,16 PM_STPPCI#
16,41 PM_SLP_S5#
17,18 +V3.3ALWAYS_ICH
+V5_LPCSLOT
6Pin_HDR
4.7K
J98
1
3
5
7
9
SMBus Debug Header
15 TP_HUB_PD11
INT_SERIRQ 15,19,20,21,29,31
PM_CLKRUN# 16,18,29,31
15,18,20 INT_PIRQH#
16 ICH_MFG_MODE
9,15,19,20 PCI_PME#
2
4
6
8
10
ICH_GPIO28 16
IDE_PATADET 16,23
IDE_SATADET 16,23
2X5-Header
KEY
16 LPC_DRQ#1
16,28,29,30,31 LPC_FRAME#
2
4
6
8
10
12
14
16
2X8_HDR
6
J41
B1
B2
B3
B4
B5
B6
B7
B8
B9
B10
B11
B12
B13
B14
B15
B16
B17
B18
B19
3,15
H_PWRGD
15,18 SM_INTRUDER#
16,18,32
PM_RI#
RP87A 1
10K
RP87C 3
10K
7 RP87B 2
10K
9,14,18,20,24,41 +V12S
1
3
5
7
9
11
13
15
ICH4-M Testpoint Header
VCC5_3
LDRQ0#
GND14
LAD3
LAD1
GND15
PCICLK
LPCPD#
GND16
PME#
VCC3_4
VCC5_1
LDRQ1#
LFRAME1#
GND9
LAD2
LAD0
GND11
PCIRST#
GND13
OSC
VCC3_3
A20
A21
A22
A23
A24
A25
A26
A27
A28
A29
A30
J85
LPC_DRQ#0 16,31
1
3
5
7
9
11
13
15
14,16,36,38 PM_STPCPU#
LPC_AD3 16,28,29,30,31
LPC_AD1 16,28,29,30,31
9,16 PM_C3_STAT#
CLK_LPCPCI 14
PM_SUS_STAT# 9,16,29,31
16,36 VR_PWRGD_ICH
PCI_PME# 9,15,19,20
2
4
6
8
10
12
14
16
3
INT_IRQ14 15,18,23
INT_IRQ15 15,18,23
PM_CLKRUN# 16,18,29,31
PM_SLP_S4# 16,29,41
2X8_HDR
60Pin_CardCon
LPC_RST#
R222
NO_STUFF_0
9,19,20,29 PCI_GATED_RST#
J68
Layout Note:
Line up LPC slot
with PCI Slot 3
R225
0
1
3
5
7
41 IDE_PPWR_EN
24,31 IDE_SPWR_EN#
NOTE:
Route Processor Test
signals stubless to
headers
BUF_PCI_RST# 9,15,19,20,21,29,30,31
2
4
6
8
FWH_WP# 16,28
FWH_TBL# 16,28
8Pin HDR
SIO Sidebands
TEST HEADER
J84
2
5,16,18,29
16,29
29,41
29,37
16,18,22,29,36
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
PM_THRM#
PM_PWRBTN#
SMC_ONOFF#
VR_ON
PM_PWROK
16,18,29 PM_RSMRST#
29,41 AC_PRESENT#
14,16,22,29,40,41 PM_SLP_S3#
29,41
29
29
21,29,33
SMC_SHUTDOWN
BAT_SUSPEND
SMC_RSTGATE#
DOCK_INTR#
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
1
3
5
7
16,29,31,33 SMC_EXTSMI#
36 IMVP_PWRGD
16 PM_GMUXSEL
J33
SMC_RUNTIME_SCI# 16,29,33
SMC_WAKE_SCI# 16,29,33
FAN_ON 29,35
SMB_THRM_CLK 5,29
SMB_THRM_DATA 5,29
2
4
6
8
2
PM_CPUPERF# 16
PM_SUS_CLK 16
AGP_SUSPEND# 16
8Pin HDR
SMB_SB_CLK 29,33,41
SMB_SB_DATA 29,33,41
SMB_SB_ALRT# 29,33,41
PM_BATLOW# 16,29,33
NO STUFF
GROUND HEADERS
SMB_SC_INT# 29
J96
15x2_HDR
1
J40
2
1
SMC Sidebands for LPC Power Management
J49
2
1
2
1
J95
1
J82
2
1
2
1
J11
J15
2
1
2
1
J34
2
J39
2
1
1
17,18,19,20,24,40,41
+V5
+V5_LPCSLOT
R210
A
+V3.3 7,9,15,17,20,24,27,29,32,36,40,41
0.01_1%
R233
+V3.3_LPCSLOT
0.01_1%
C270
C261
C287
C218
C220
C276
Title
22UF
0.1UF
22UF
0.1UF
0.1UF
0.1UF
Size
A
Date:
B
C
LPC Slot & Debug Headers
Document Number
Project:
855PM Platform
Monday, February 24, 2003
D
Sheet
Rev
of
34
E
47
A
B
C
D
E
Fan Power Control
4
4
9,17,20,21,24,31,32,33,36,37,38,41,42 +V5S
3 FAN_ON_Q
1000PF
3
C199
0.1UF
22UF
CR15
1N4148
1
2
FAN_ON_D
CONN2_HDR
J20
3
Q28
BSS138
1
2
29,34 FAN_ON
R127
100K
U27
SI3457DV
C200
3
C205
3
R125
1M
+V5_FAN
+
1
6
5
2
1
4
2
2
1
1
Title
Fan Circuit
Size Project:
A
855PM Platform
Date:
Monday, February 24, 2003
A
B
C
D
Document Number
Sheet
of
35
E
Rev
47
14
U17A
4
ON_BOARD_VR_PWRGD
1
INTERPOSER_PRES#
2
74HC00
PWRGD1
3
4
74HC00
6
2
4
MAIN_PWROK
2
+V3.3ALWAYS
+V3.3
U8
1
DDR_VR_PWRGD
74AHC1G08
4
8
PWRGD3
13
9
74HC00
34
Q38
2N3904
2
PWRGD2
+V3.3S
R363
100K
IMVP_PWRGD_D 1
IMVP_PWRGD
VR_PWRGD_CK408# 14
3
R254
10K_1%
11
12
7
4
3
14U17D
16,18,22,29,34
R255
10K
74AHC1G08
14
U17C
PM_PWROK
2
18 V5A_PWRGD
+V3.3S
1
4
5
40
7
74HC00
V1.5_PWRGD
5,9,16,17,18,19,20,24,25,26,29,33,34,41
IMVP_PWRGD 34
7
10
PWR_PWROK
17
U9
74AHC1G08
5
7,9,15,17,20,24,27,29,32,34,40,41
41
5,9,10,14,15,17,18,20,23,28,30,31,32,33,37,38,41,42
U4
3
38
14
U17B
1
E
5,9,16,17,18,19,20,24,25,26,29,33,34,41
5
+V3.3
D
+V3.3ALWAYS
5
7,9,15,17,20,24,27,29,32,34,40,41
C
3
B
VR PWRGD CIRCUIT
MAIN2_PWROK
A
5,9,10,14,15,17,18,20,23,28,30,31,32,33,37,38,41,42
5,9,10,14,15,17,18,20,23,28,30,31,32,33,37,38,41,42
+V3.3S 5,9,10,14,15,17,18,20,23,28,30,31,32,33,37,38,41,42
+V3.3S
7
OFF_BOARD_VR_PWRGD
VDD+
OPAMP_N
3
2
R268
10K
10
U43A
TLV2463
OPAMP_P
2
Processor VID TABLE
3
2
1
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
VCC
Core 5
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
1.708
1.692
1.676
1.660
1.644
1.628
1.612
1.596
1.580
1.564
1.548
1.532
1.516
1.500
1.484
1.468
1.452
1.436
1.420
1.404
1.388
1.372
1.356
1.340
1.324
1.308
1.292
1.276
1.260
1.244
1.228
1.212
A
VID
4
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
3
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
2 1 0
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
Q36
BSS84
1
C288
1uF
20%
VR_PWRGD_ICH_D
OPAMP_EN
+V3.3S
1
OFF_BOARD_VR_ON
2
5,9,10,14,15,17,18,20,23,28,30,31,32,33,37,38,41,42
U19
4
ON_BOARD_VR_ON 38
3
74AHC1G08
+
R256
10K
GND
4
R251
2K_1%
CR23
VCC
Core
3
3
1
VR_PWRGD_ICH
16,34
BAT54
1.196
1.180
1.164
+V3.3S 5,9,10,14,15,17,18,20,23,28,30,31,32,33,37,38,41,42
1.148
1.132
+V5S 9,17,20,21,24,31,32,33,35,37,38,41,42
+V3.3S 5,9,10,14,15,17,18,20,23,28,30,31,32,33,37,38,41,42
1.116
1.100
+V3.3S 5,9,10,14,15,17,18,20,23,28,30,31,32,33,37,38,41,42
1.084
J29
1
2
1.068
38,42 VR_VID0
VR_VID3 38,42
+V5S 9,17,20,21,24,31,32,33,35,37,38,41,42
3
4
38,42
VR_VID1
VR_VID4 38,42
1.052
5
6
38,42 VR_VID2
VR_VID5 38,42
1.036
7
8
9
10
1.020
U18
J30
11
12
1.004
OFF_BOARD_VR_PWRGD
INTERPOSER_PRES#
1
1
2
13
14
37 CORE_VR_ON
PM_STPCPU# 14,16,34,38
OFF_BOARD_VR_ON
4
3
4
15
16
0.988
PM_DPRSLPVR 16,34,38
2
5
6 NC5_D
17
18
29 VR_SHUT_DOWN#
0.972
TP_NC_5
3
R52
7
8
19
20
Connector 2
0.956
74AHC1G08
0
9
10
21
22
(rows C,D)
11
12
23
24
0.940
13
14
25
26
0.924
15
16
27
28
0.908
17
18
29
30
19
20
31
32
Connector 1
0.892
21
22
33
34
+V3.3S
+VDC 18,37,38,41
(rows A,B)
0.876 5,9,10,14,15,17,18,20,23,28,30,31,32,33,37,38,41,42
23
24
35
36
25
26
37
38
10
0.860
VDD+
U43B
27
28
39
40
0.844
TLV2463
29
30
U43_TP1
20x2_Header
0.828
8
31
32
U43_TP2
33
34
0.812
9
35
36
0.796
6
37
38
R3007
R3008
7
39
40
0.780
+
1K
1K
0.764
Title
20x2_Header
Processor Voltage Regulator Module
GND
0.748
4
0.732
Size Project:
Document Number
Rev
Custom
855PM Platform
0.716
VR Interposer Headers
0.700
Date:
Monday, February 24,
Sheet
2003
36
of 47
2
5
VID
4
IMVP_PWRGD
1
5
INTERPOSER_PRES#
3
34
3
5
R366
1M
R250
1.58K
1%
3
R269
10K
B
C
D
E
1
5
4
3
2
1
855PM Core and Processor
IO VR's (+VCCP)
D
C
+V5S
D
C
9,17,20,21,24,31,32,33,35,36,41
+VDC 18,36,41
+VCCP 3,4,5,7,15,16,17,39
+V1.2S_MCH
29,34 VR_ON
7,39
IMVP-IV
CORE_VR_ON 36
B
B
A
A
Title
855PM VR AND VCCP
Size Project:
C
855PM Platform
Date:
Monday, February 24, 2003
5
4
3
2
Document Number
Sheet
1
37
of
Rev
47
5
4
3
2
1
IMVP-IV Core VR
D
D
C
C
+V3.3S 5,9,10,14,15,17,18,20,23,28,30,31,32,33,36,41
+V5S
9,17,20,21,24,31,32,33,35,36,41
+VDC 18,36,41
+VCC_CORE
4,39
14,16,34,36 PM_STPCPU#
36 ON_BOARD_VR_ON
16,34,36
PM_DPRSLPVR
IMVP-IV
ON_BOARD_VR_PWRGD 36
B
B
A
A
Title
IMVP-IV VR Controller
Size Project:
C
855PM Platform
Date:
Monday, February 24, 2003
5
4
3
2
Document Number
Sheet
1
38
of
Rev
47
5
4
3
2
1
VCore HF and Bulk Decoupling
This solution will allow any of the
decoupling options. All caps should NOT
be stuffed at the same time.
D
4,38 +VCC_CORE
D
NO_STUFF_10UF
NO_STUFF_10UF
C362
C372
C365
C356
NO_STUFF_10UF
C360
C359
C355
C373
C374
C124
NO_STUFF_10UF
NO_STUFF_10UF
C125
C111
C371
C127
NO_STUFF_10UF
C109
C361
NO_STUFF_10UF
NO_STUFF_10UF
C357
C366
C358
C126
NO_STUFF_10UF
NO STUFF
NO_STUFF_10UF
NO_STUFF_10UF
NO_STUFF_10UF
NO_STUFF_10UF
NO_STUFF_10UF
NO_STUFF_10UF
NO_STUFF_10UF
NO_STUFF_10UF
NO_STUFF_10UF
NO_STUFF_10UF
NO_STUFF_10UF
NO_STUFF_10UF
NO_STUFF_10UF
NO_STUFF_10UF
4,38 +VCC_CORE
NO_STUFF_10UF
NO_STUFF_10UF
NO_STUFF_10UF
NO_STUFF_10UF
NO_STUFF_10UF
NO_STUFF_10UF
C
C
C370
C364
C114
NO_STUFF_10UF
C122
C108
C369
C110
C123
C113
C120
C118
C117
NO_STUFF_10UF
NO_STUFF_10UF
NO_STUFF_10UF
NO_STUFF_10UF
NO_STUFF_10UF
C138
150UF
C105
150UF
C135
150UF
C132
150UF
C131
150UF
C119
C116
NO_STUFF_10UF
C121
C112
NO_STUFF_10UF
C363
C115
NO_STUFF_10UF
C368
C367
NO_STUFF_10UF
NO STUFF
NO_STUFF_10UF
4,38 +VCC_CORE
C140
150UF
C139
150UF
C137
150UF
C136
150UF
C134
150UF
C133
150UF
Bulk decoupling values are tuned
to Intels IMVP-IV 2Phase VR design.
Circuits using other converter topologies
may have different requirements.
C104
150UF
B
B
4,38 +VCC_CORE
C376
C378
C379
C380
C389
C390
C391
C392
C384
C377
C381
C382
C383
C385
C386
2.2uF
2.2uF
2.2uF
2.2uF
2.2uF
2.2uF
2.2uF
2.2uF
2.2uF
2.2uF
2.2uF
2.2uF
2.2uF
2.2uF
2.2uF
3,4,5,7,15,16,17,37,42
+VCCP
3,4,5,7,15,16,17,37,42
Place near 855PM
+VCCP
Place near CPU
C167
C400
C399
C422
C413
C402
C410
C412
C435
C165
C3900
C171
C395
C401
C406
C393
C403
C394
C398
C409
C405
C408
C396
150UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
NO_STUFF_150UF
NO_STUFF_150UF
150UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
0.1UF
NO_STUFF_150UF
Note:
C417 is 0805
7,37 +V1.2S_MCH
A
Note:
2.2uF Caps are
0612 geometry
C164
C166
C163
C417
NO_STUFF_150UF
150UF
150UF
2.2UF
A
1
2
C431
C433
C425
C434
C432
0.22uF
0.047UF
0.022uF
0.01UF
0.015uF
Title
Decoupling
Size Project:
B
855PM Platform
Date:
Monday, February 24, 2003
5
4
3
2
Document Number
Sheet
1
39
of
Rev
47
5
4
3
2
1
17,18,19,20,24,34,41 +V5
BOOT_1
C273
C272
150uF
C274
150uF
0.1UF
C263
47pF
D
VSENSE_1
2
COMP_1
3
C473
COMP_1_D 1
R429
2
25.5k_1%
5600pF
4
5
RT_1
28
27
SS/ENA_1
J55
R199
NO_STUFF_10K
C250
0.01UF
3
1
CON3_HDR
V2.5_DDR_D
VIN0
VIN1
VIN2
VIN3 TPS54610
VIN4
VSENSE
NC/Comp
PWRGD
6
7
8
9
10
11
12
13
14
PH0
PH1
PH2
PH3
PH4
PH5
PH6
PH7
PH8
Single point
sense
near load
13 +V2.5
L8
PH_1 1
BOOT
RT
2
C248
D
4.7uH
0.1UF
7,8 +V2.5_MCH
1
AGND
R200
19
PGND0
18
PGND1
17
PGND2
SS/ENA
16
PGND3
25
15
PGND4
VBAIS
Note for layout: This part has
special pad on it's underside
FSEL
0.01_1%
26
R227
5.49k_1%
VBIAS_1
2
R423
NO_STUFF_10K_1%
10,13 +V2.5_DDR
0.022uF
U34
24
23
22
21
20
PwrPad
C271
R426
10K_1%
17,18,19,20,24,34,41 +V5
C249
17,18,19,20,24,34,41 +V5
0.1UF
VSENSE_1_D 1
R427
221_1%
2
C472
8200pF
10
7,8 +V2.5_MCH
8
-
U40B
TLV2463
GND_DDR
R459
10K
C280
0.1UF
VDD+
Do Not Stuff
J54
1
2
R428
5.49k_1%
R226
0
R236
OPAMP1_P 7
0
J58
2
1
C286
7,8 +V2.5_MCH
C
9
6
SM_VREF_DIMM 10
OPAMP1_EN
+
GND
4
3
R456
NO_STUFF_10K
C
NO_STUFF_0.01UF
NO_STUFF_CON3_HDR
VR divider resistors
should be 0.1% tolerant
7,9,15,17,20,24,27,29,32,34,36,41 +V3.3
R466
10K_1%
7,8 +V2.5_MCH
R23
10K
R232
NO_STUFF_0
17,18,19,20,24,34,41 +V5
DDR_VR_PWRGD 36
J57
R480
10K_1%
C488
0.01UF
C277
2
2
3
NO_STUFF_0.01UF
NO_STUFF_CON3_HDR
Do Not Stuff
OPAMP2_P
1
J56
1
Note:
DO NOT STUFF R223
if both OP-AMPS
are enabled
VDD+
17,18,19,20,24,34,41 +V5
2
3
C295
C299
150uF
150uF
0.1UF
NO_STUFF_0
VSENSE_2
2
COMP_2
C292
220PF
3
4
C494
BOOT_2
COMP_2_D
5
RT_2
0.082uF
28
FSEL
27
VBIAS_2
100K
VIN0
VIN1
VIN2
VIN3 TPS54672
VIN4
VSENSE
NC/Comp
STATUS
BOOT
RT
PH0
PH1
PH2
PH3
PH4
PH5
PH6
PH7
PH8
6
7
8
9
10
11
12
13
14
J53
1
OPAMP2_EN
0
2
Do Not Stuff
+
R458
10K
SM_VREF_MCH 6
AGND
B
Vtt Sense
Single point
sense
near load
L9
PH_2
1
+VDDR
2
4.7uH
6,12,13,42 +V1.25S
R274
0.01_1%
1
19
PGND0
18
PGND1
17
PGND2
16
PGND3
25
15
PGND4
VBAIS
Note for layout: This part has
special pad on it's underside
26
R263
R223
U45
24
23
22
21
20
B
R487
4.99k_1%
U40A
TLV2463
1
5
-
GND
4
R489
PwrPad
C294
R457
NO_STUFF_10K
10
REFIN_2
ENA
C304
C330
C309
C296
C303
REFIN
150uF
150uF
150uF
150uF
0.1UF
C291
0.1UF
R476
3.92k_1%
C298
VSENSE_2_D
R474
267_1%
C491
1
2
0.022uF
8200pF
R484
NO_STUFF_4.99k_1%
14,16,22,29,34,41 PM_SLP_S3#
Vtt Sense
R258
0
R475
NO_STUFF_0
FSEL
Vtt Sense
A
A
17,41 DC_SLP_S5#
DDR VR
5
4
Title
DDR_VR
Size Project:
C
855PM Platform
Date:
Monday, February 24, 2003
3
2
Document Number
Sheet
1
40
of
Rev
47
5
4
3
HDM Connector Assembly (base board)
2
1
HDM conn. is a modulized conn. design in 2 parts.
3 pin power recepticle and a 72 pin recepticle.
The 2 parts will be arranged as shown on this
schematic page.
J20
A1
A2
A3
A4
18,36,37,38 +VDC
19,20 -V12S
D1
D2
D3
D4
D
C8
22UF
35V
F1
F2
F3
F4
3Pin_RECEPTICLE
16,34 PM_SLP_S5#
1
16,29,34 PM_SLP_S4#
2
CON3,RCPTL,TH,700000-667.Normal
4,7,8,17 +V1.8S
J22
9,14,18,20,24,34
+V12S
U52
4
C28
22UF
35V
DC_SLP_S5# 17,40
74AHC1G08
9,17,20,21,24,31,32,33,35,36,37,38,42
3
A1
A2
A3
A4
4,6,7,9,17
+V5S
+V1.5S
C210
D1
D2
D3
D4
+V3.3S 5,9,10,14,15,17,18,20,23,28,30,31,32,33,36,37,38,42
R74
V3.3S_TURNER
22UF
F1
F2
F3
F4
0.002
1%
C91
22UF
+V3.3ALWAYS
5
5,9,16,17,18,19,20,24,25,26,29,33,34,36
17,18,19,20,24,34,40
+V5
C189
9,17,20,21,24,31,32,33,35,36,37,38,42
+V5S
22UF
3Pin_RECEPTICLE
C
D
C
CON3,RCPTL,TH,700000-667.Normal
29,34 AC_PRESENT#
29,34 SMC_SHUTDOWN
29,34 SMC_ONOFF#
29,33,34 SMB_SB_CLK
29,33,34 SMB_SB_DATA
29,33,34 SMB_SB_ALRT#
34 IDE_PPWR_EN
14,16,22,29,34,40 PM_SLP_S3#
14,16,24 PM_SLP_S1#
36 PWR_PWROK
A1
A2
A3
A4
A5
A6
A7
A8
A9
A10
A11
A12
B1
B2
B3
B4
B5
B6
B7
B8
B9
B10
B11
B12
C1
C2
C3
C4
C5
C6
C7
C8
C9
C10
C11
C12
DC_SLP_S5#
PS_ON_SW#
19,20 -V12S
-V12S_TURNER
R83
+V3.3ALWAYS
0.01_1%
5,9,16,17,18,19,20,24,25,26,29,33,34,36
V3.3A_TURNER
B
R113
0.01_1%
C176
22UF
72Pin_RECEPTICLE(male)
J23
V5S_TURNER
F12
F11
F10
F9
F8
F7
F6
F5
F4
F3
F2
F1
E12
E11
E10
E9
E8
E7
E6
E5
E4
E3
E2
E1
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
R111
0.01_1%
9,14,18,20,24,34
+V12S
V12S_TURNER
R104
0.01_1%
9,17,20,21,24,31,32,33,35,36,37,38,42
+V5S
9,17,20,21,24,31,32,33,35,36,37,38,42
R333
330
+V5 17,18,19,20,24,34,40
FRONT1
5,9,10,14,15,17,18,20,23,28,30,31,32,33,36,37,38,42
+V3.3S
1
3
5
7
9
11
13
15
23,24 IDE_PDACTIVE#
RST_PUSH#
C327 C329 C326
470PF 470PF 470PF
R338
10K
U51
SW4
3
4
1
2
Push button
C323
0.1UF
RST_PUSH#
1
GND
VCC
4
2
IN
OUT
3
C325
C328
470PF
470PF
PS_ON_SW#
B
16
Front Panel
+V3.3ALWAYS
5
17,18,19,20,24,34,40
+V5
5,9,16,17,18,19,20,24,25,26,29,33,34,36
U30
1
4
3,5 ITP_DBRESET#
PM_SYSRST# 16
74AHC1G08
R115
0.01_1%
3
D1
D2
D3
D4
2
V5_TURNER
A
F1
F2
F3
F4
Title
3Pin_RECEPTICLE
CON3,RCPTL,TH,700000-667.Normal
DC/DC Card Connector
Size Project:
B
855PM Platform
Date:
Monday, February 24, 2003
5
1
2
Push button
RESET
+V3.3 7,9,15,17,20,24,27,29,32,34,36,40
V3.3_TURNER
POWER
SW3
3
4
MASTER_RESET#
MAX6816
A1
A2
A3
A4
0.01_1%
FRONT2
2
4
6
8
10
12
HDR_2x8
J31
R118
R336
330
J99
CON72,RCPTL,TH,700000-668.Normal
A
+V5S
4
3
2
Document Number
Sheet
1
41
of
Rev
47
A
B
C
D
E
4
4
3
3
PAGE INTENTIONALLY LEFT BLANK
2
2
1
1
Title
DEBUG LOGIC
Size Project:
A
855PM Platform
Date:
Monday, February 24, 2003
A
B
C
D
Document Number
Sheet
of
42
E
Rev
47
A
B
C
D
E
Power On Sequence
6
+V5S
6
+V5
6
+V12S
6
-V12S
1
POWER
4
PG 15,16
PG 41
U4
7
6
2
+V3A
U49
PG 17
+V1.5A
MAIN_PWROK
MAIN2_PWROK
PG 36
8
U9
PM_PWROK
U8
CPU
SMC
2
VR_PWRGD_CK408#
9
SMC_PROG_RST#
SMC_RST#
RST_HDR
U6
VR_ON
+V2.5
+V1.25S
PG 3
PG 29
PG 29
+V5A VR
15
CK-408
PG 14
2
+V5_ALWAYS
INTERPOSER_PRES#
ON_BOARD_VR_ON
14
3
18
PG 38
+V3A
2
PG 36
PG 38
16
PG 36
MAX809
PG 30
Core VR
PG 6,7
3 3
DDR VR
PG 18
MCH
PG 36
SMC_ONOFF#
PG 40
4
PS_ON_SW#
PWR_PWROK
PG 41
3
PM_SLP_S3#
17
H_CPURST#
+V3.3S
ICH4
H_PWRGD
6
4
VR_PWRGD_ICH
+V3.3
PM_SLP_S5#
PCI_RST#
IMVP_PWRGD
6
U52
PG 41
4
PM_RSMRST#
+V1.5S
5
DC_SLP_S5#
17
PM_SLP_S4#
PM_PWRBTN#
6
V5A_PWRGD
+V1.8S
DC/DC
DDR_VR_PWRGD
6
V1.5_PWRGD
4
+VDC
VR_SHUTDOWN
U19
U18
13
12
PG 36
PG 36
ON_BOARD_VR_PWRGD
855PM &
VCCP VR
VCCP_PGD
CORE_VR_ON
U20
11
PG 37
855PM_PGD
PG 37
10
IMVP_PWRGD
PG 36
1
1
Title
Power On Checklist
Size Project:
A
855PM Platform
Monday, February 24, 2003
Date:
A
B
C
D
Document Number
Sheet
43
of
E
Rev
47