Pentium® III Xeon™ Processor at 500 and
550 MHz
Datasheet
Product Features
n
n
n
n
n
n
n
Binary compatible with applications
running on previous members of the Intel
microprocessor family
Optimized for 32-bit applications running
on advanced 32-bit operating systems
Dynamic Execution micro architecture
Dual Independent Bus architecture:
Separate dedicated external 100MHz
System Bus and dedicated internal cache
bus operating at full processor core speed
Power Management capabilities
— System Management mode
— Multiple low-power states
SMBus interface to advanced
manageability features
Intel® processor serial number
n
n
n
n
n
n
Single Edge Contact (S.E.C.) cartridge
packaging technology; the S.E.C. cartridge
delivers high performance processing and
bus technology in mid-range to high-end
servers and workstations
100 MHz system bus speeds data transfer
between the processor and the system
Integrated high performance16K
instruction and 16K data, nonblocking,
level-one cache
Available in 512K, 1 M, or 2 M unified,
nonblocking level-two cache
Enables systems which are scaleable up to
four processors and 64 GB of physical
memory
Streaming SIMD Extensions for enhanced
video, sound and 3D performance
The Intel® Pentium® III Xeon™ processor is designed for mid-range to high-end servers and workstations, and is binary
compatible with previous Intel Architecture processors. The Pentium III Xeon processor provides the best performance
available for applications running on advanced operating systems such as Windows* 95, Windows NT, and UNIX*. The
Pentium III Xeon processor is scalable to four processors in a multiprocessor system and extends the power of the
Pentium® Pro processor with new features designed to make this processor the right choice for powerful workstation,
advanced server management, and mission-critical applications. Pentium III Xeon processor-based workstations offer
the memory architecture required by the most demanding workstation applications and workloads. Specific features of
the Pentium III Xeon processor address platform manageability to meet the needs of a robust IT environment, maximize
system up time and ensure optimal configuration and operation of servers. The Pentium III Xeon processor enhances the
ability of server platforms to monitor, protect, and service the processor and its environment.
Order Number: 245094-002
February 2000
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.
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 Pentium® III Xeon™ processor 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.
Copies of documents which have an ordering number and are referenced in this document, or other Intel literature may be obtained by calling 1-800548-4725 or by visiting Intel's website at http://www.intel.com.
Copyright © Intel Corporation, 2000
*Third-party brands and names are the property of their respective owners.
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Contents
1.0
Introduction.........................................................................................................................9
1.1
1.2
2.0
Electrical Specifications....................................................................................................11
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
2.10
2.11
2.12
3.0
3.3
System Bus Clock Signal Quality Specifications.................................................33
AGTL+ Signal Quality Specifications ..................................................................33
3.2.1 AGTL+ Ringback Tolerance Specifications............................................34
3.2.2 AGTL+ Overshoot/Undershoot Guidelines.............................................34
Non-AGTL+ Signal Quality Specifications...........................................................35
3.3.1 2.5 V Tolerant Buffer Overshoot/Undershoot Guidelines .......................35
3.3.2 2.5 V Tolerant Buffer Ringback Specification.........................................35
3.3.3 2.5 V Tolerant Buffer Settling Limit Guideline ........................................36
Processor Features ..........................................................................................................36
4.1
4.2
4.3
Datasheet
The Pentium® III Xeon™ Processor System Bus and VREF ...............................11
Power and Ground Pins ......................................................................................12
Decoupling Guidelines ........................................................................................12
2.3.1 Pentium® III Xeon™ Processor VCCCORE ..............................................13
2.3.2 Level 2 Cache Decoupling .....................................................................13
2.3.3 System Bus AGTL+ Decoupling.............................................................13
System Bus Clock and Processor Clocking ........................................................13
2.4.1 Mixing Processors ..................................................................................15
Voltage Identification ...........................................................................................16
System Bus Unused Pins and Test Pins.............................................................17
System Bus Signal Groups .................................................................................18
2.7.1 Asynchronous vs. Synchronous for System Bus Signals.......................19
Test Access Port (TAP) Connection....................................................................19
Maximum Ratings................................................................................................20
Processor DC Specifications...............................................................................20
AGTL+ System Bus Specifications .....................................................................24
System Bus AC Specifications ............................................................................25
Signal Quality ...................................................................................................................32
3.1
3.2
4.0
Terminology...........................................................................................................9
1.1.1 S.E.C. Cartridge Terminology ................................................................10
References ..........................................................................................................10
Functional Redundancy Checking Mode.............................................................36
Low Power States and Clock Control..................................................................37
4.2.1 Normal State— State 1 ..........................................................................37
4.2.2 Auto Halt Power Down State — State 2 .................................................37
4.2.3 Stop-Grant State — State 3 ...................................................................38
4.2.4 Halt/Grant Snoop State — State 4 .........................................................39
4.2.5 Sleep State — State 5............................................................................39
4.2.6 Clock Control..........................................................................................39
System Management Bus (SMBus) Interface .....................................................40
4.3.1 Processor Information ROM...................................................................41
4.3.2 Scratch EEPROM...................................................................................42
3
Pentium® III Xeon™ Processor at 500 and 550 MHz
4.3.3
4.3.4
4.3.5
4.3.6
4.3.7
5.0
Thermal Specifications and Design Considerations.........................................................49
5.1
5.2
6.0
7.3
Introduction .........................................................................................................71
Mechanical Specifications...................................................................................71
7.2.1 Boxed Processor Heatsink Dimensions ................................................. 73
7.2.2 Boxed Processor Heatsink Weight.........................................................73
7.2.3 Boxed Processor Retention Mechanism ................................................ 73
Thermal Specifications........................................................................................74
7.3.1 Boxed Processor Cooling Requirements ...............................................74
7.3.2 Optional Auxiliary Fan Attachment .........................................................74
7.3.2.1 Clearance Recommendations for Auxiliary Fan ........................ 76
7.3.2.2 Fan Power Recommendations for Auxiliary Fan ....................... 77
7.3.2.3 Thermal Evaluation for Auxiliary Fan ........................................ 78
Integration Tools ..............................................................................................................78
8.1
4
Weight .................................................................................................................60
Cartridge to Connector Mating Details ................................................................60
Pentium® III Xeon™ Processor Substrate Edge Finger Signal Listing ............... 62
Boxed Processor Specifications.......................................................................................71
7.1
7.2
8.0
Thermal Specifications........................................................................................50
5.1.1 Power Dissipation ..................................................................................50
5.1.2 Plate Flatness Specification ...................................................................51
Processor Thermal Analysis ...............................................................................51
5.2.1 Thermal Solution Performance...............................................................51
5.2.2 Thermal Plate to Heat Sink Interface Management Guide..................... 52
5.2.3 Measurements for Thermal Specifications............................................. 53
5.2.3.1 Thermal Plate Temperature Measurement ............................... 53
5.2.3.2 Cover Temperature Measurement Guideline ............................ 54
Mechanical Specifications................................................................................................55
6.1
6.2
6.3
7.0
Processor Information ROM and Scratch EEPROM Supported
SMBus Transactions ..............................................................................43
Thermal Sensor......................................................................................43
Thermal Sensor Supported SMBus Transactions..................................44
Thermal Sensor Registers......................................................................46
4.3.6.1 Thermal Reference Registers ................................................... 46
4.3.6.2 Thermal Limit Registers ............................................................46
4.3.6.3 Status Register..........................................................................46
4.3.6.4 Configuration Register...............................................................47
4.3.6.5 Conversion Rate Register .........................................................47
SMBus Device Addressing.....................................................................48
In-Target Probe (ITP) for Pentium® III Xeon™ Processors................................. 78
8.1.1 Primary Function ....................................................................................79
8.1.2 Debug Port Connector Description.........................................................79
8.1.3 Debug Port Signal Descriptions .............................................................80
8.1.4 Debug Port Signal Notes........................................................................82
8.1.4.1 General Signal Quality Notes .................................................... 83
8.1.4.2 Signal Note: DBRESET#...........................................................83
8.1.4.3 Signal Note: TDO and TDI ........................................................83
8.1.4.4 Signal Note: TCK.......................................................................83
8.1.5 Using Boundary Scan to Communicate to the Processor ...................... 85
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
8.2
9.0
Appendix ..........................................................................................................................86
9.1
Datasheet
Integration Tool (Logic Analyzer) Considerations ...............................................86
Alphabetical Signals Reference ..........................................................................86
9.1.1 A[35:03]# (I/O)........................................................................................86
9.1.2 A20M# (I)................................................................................................86
9.1.3 ADS# (I/O)..............................................................................................87
9.1.4 AERR# (I/O) ...........................................................................................87
9.1.5 AP[1:0]# (I/O) .........................................................................................87
9.1.6 BCLK (I)..................................................................................................87
9.1.7 BERR# (I/O) ...........................................................................................87
9.1.8 BINIT# (I/O) ............................................................................................88
9.1.9 BNR# (I/O)..............................................................................................88
9.1.10 BP[3:2]# (I/O) .........................................................................................88
9.1.11 BPM[1:0]# (I/O) ......................................................................................88
9.1.12 BPRI# (I).................................................................................................88
9.1.13 BR0# (I/O), BR[3:1]# (I) ..........................................................................88
9.1.14 CPU_SENSE..........................................................................................89
9.1.15 D[63:00]# (I/O)........................................................................................89
9.1.16 DBSY# (I/O) ...........................................................................................90
9.1.17 DEFER# (I).............................................................................................90
9.1.18 DEP[7:0]# (I/O).......................................................................................90
9.1.19 DRDY# (I/O) ...........................................................................................90
9.1.20 EMI .........................................................................................................90
9.1.21 FERR# (O) .............................................................................................90
9.1.22 FLUSH# (I) .............................................................................................90
9.1.23 FRCERR (I/O) ........................................................................................91
9.1.24 HIT# (I/O), HITM# (I/O) ..........................................................................91
9.1.25 IERR# (O)...............................................................................................91
9.1.26 IGNNE# (I)..............................................................................................91
9.1.27 INIT# (I) ..................................................................................................92
9.1.28 INTR - see LINT0 ...................................................................................92
9.1.29 LINT[1:0] (I) ............................................................................................92
9.1.30 LOCK# (I/O) ...........................................................................................92
9.1.31 L2_SENSE .............................................................................................93
9.1.32 NMI - See LINT1 ....................................................................................93
9.1.33 PICCLK (I) ..............................................................................................93
9.1.34 PICD[1:0] (I/O)........................................................................................93
9.1.35 PM[1:0]# (O) ...........................................................................................93
9.1.36 PRDY# (O) .............................................................................................93
9.1.37 PREQ# (I)...............................................................................................93
9.1.38 PWREN[1:0] (I).......................................................................................93
9.1.39 PWRGOOD (I)........................................................................................93
9.1.40 REQ[4:0]# (I/O) ......................................................................................94
9.1.41 RESET# (I) .............................................................................................94
9.1.42 RP# (I/O) ................................................................................................95
9.1.43 RS[2:0]# (I) .............................................................................................95
9.1.44 RSP# (I)..................................................................................................95
9.1.45 SA[2:0] (I) ...............................................................................................95
9.1.46 SELFSB[1:0] (I/O) ..................................................................................96
5
Pentium® III Xeon™ Processor at 500 and 550 MHz
9.2
9.1.47 SLP# (I) ..................................................................................................96
9.1.48 SMBALERT# (O)....................................................................................96
9.1.49 SMBCLK (I) ............................................................................................96
9.1.50 SMBDAT (I/O) ........................................................................................96
9.1.51 SMI# (I) ..................................................................................................96
9.1.52 STPCLK# (I)...........................................................................................97
9.1.53 TCK (I)....................................................................................................97
9.1.54 TDI (I) .....................................................................................................97
9.1.55 TDO (O) .................................................................................................97
9.1.56 TEST_25_A62 (I) ...................................................................................97
9.1.57 TEST_VCC_CORE_XXX (I)...................................................................97
9.1.58 THERMTRIP# (O) ..................................................................................97
9.1.59 TMS (I) ...................................................................................................98
9.1.60 TRDY# (I) ...............................................................................................98
9.1.61 TRST# (I) ...............................................................................................98
9.1.62 VID_L2[4:0], VID_CORE[4:0](O)............................................................98
9.1.63 WP (I) .....................................................................................................98
Signal Summaries ...............................................................................................98
Figures
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
26
27
28
6
Timing Diagram of Clock Ratio Signals...............................................................15
Logical Schematic for Clock Ratio Pin Sharing................................................... 15
I-V Curve for nMOS Device.................................................................................23
BCLK, PICCLK, TCK Generic Clock Waveform.................................................. 29
SMBCLK Clock Waveform ..................................................................................29
Valid Delay Timings ............................................................................................29
Setup and Hold Timings......................................................................................30
FRC Mode BCLK to PICCLK Timing...................................................................30
System Bus Reset and Configuration Timings.................................................... 31
Power-On Reset and Configuration Timings.......................................................31
Test Timings (Boundary Scan)............................................................................32
Test Reset Timings .............................................................................................32
BCLK, TCK, PICCLK Generic Clock Waveform at the Processor Core Pins...... 33
Low to High AGTL+ Receiver Ringback Tolerance............................................. 34
Non-AGTL+ Overshoot/Undershoot, Settling Limit, and Ringback ..................... 35
Stop Clock State Machine...................................................................................38
Logical Schematic of SMBus Circuitry ................................................................40
Thermal Plate View .............................................................................................50
Plate Flatness Reference....................................................................................51
Interface Agent Dispensing Areas and Thermal Plate Temperature
Measurement Points ...........................................................................................53
Technique for Measuring TPLATE with 0° Angle Attachment ............................... 54
Technique for Measuring TPLATE with 90° Angle Attachment ............................. 54
Guideline Locations for Cover Temperature (TCOVER) Thermocouple
Placement ...........................................................................................................55
Isometric View of Pentium® III Xeon™ Processor S.E.C. Cartridge ................... 56
S.E.C. Cartridge Cooling Solution Attach Details (Notes follow Figure 27) ........ 57
S.E.C. Cartridge Retention Enabling Details (Notes follow Figure 27) ............... 58
S.E.C. Cartridge Retention Enabling Details.......................................................59
Side View of Connector Mating Details...............................................................60
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
Top View of Cartridge Insertion Pressure Points ................................................61
Front View of Connector Mating Details..............................................................61
Boxed Pentium® III Xeon™ Processor................................................................71
Side View Space Requirements for the Boxed Processor ..................................72
Front View Space Requirements for the Boxed Processor .................................73
Front Views of the Boxed Processor with Attached Auxiliary Fan
(Not Included with Boxed Processor) ..................................................................75
Front View of Boxed Processor Heatsink with Fan Attach Features
(Fan Not Included)...............................................................................................75
Cross-sectional View of Grommet Attach Features in the Heatsink
(Grommet Shown) ...............................................................................................76
Side View Space Recommendation for the Auxiliary Fan ...................................76
Front View Space Recommendations for the Auxiliary Fan ................................77
Boxed Processor Fan/Heatsink Power Cable Connector Description.................77
Hardware Components of an ITP........................................................................79
AGTL+ Signal Termination ..................................................................................82
TCK with Individual Buffering Scheme ................................................................84
System Preferred Debug Port Layout .................................................................85
PWRGOOD Relationship at Power-On ...............................................................94
Tables
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
Datasheet
Core Frequency to System Bus Multiplier Configuration.....................................14
Core and L2 Voltage Identification Definition ......................................................16
Pentium® III Xeon™ Processor System Bus Pin Groups....................................18
Pentium® III Xeon™ Processor Absolute Maximum Ratings ..............................20
Voltage Specifications ........................................................................................21
Current Specifications .........................................................................................22
AGTL+ Signal Groups, DC Specifications at the Processor Core.......................23
CMOS, TAP, Clock and APIC Signal Groups, DC Specifications at the
Processor Core ...................................................................................................24
SMBus Signal Group, DC Specifications at the Processor Core ........................24
Pentium® III Xeon™ Processor Internal Parameters for the AGTL+ Bus............25
System Bus AC Specifications (Clock) at the Processor Core............................25
AGTL+ Signal Groups, System Bus AC Specifications at the Processor Core...26
CMOS, TAP, Clock and APIC Signal Groups, AC Specifications at the
Processor Core ...................................................................................................26
System Bus AC Specifications (Reset Conditions) .............................................27
System Bus AC Specifications (APIC Clock and APIC I/O) at the Processor
Core.....................................................................................................................27
System Bus AC Specifications (TAP Connection) at the Processor Core ..........28
SMBus Signal Group, AC Specifications at the Edge Fingers ............................28
BCLK Signal Quality Specifications for Simulation at the Processor Core..........33
AGTL+ Signal Groups Ringback Tolerance Specifications at the Processor
Core.....................................................................................................................34
AGTL+ Overshoot/Undershoot Guidelines at the Processor Core......................35
2.5 V Tolerant Signal Overshoot/Undershoot Guidelines at the Processor Core35
Signal Ringback Specifications for 2.5V Tolerant Signal Simulation at the
Processor Core ...................................................................................................36
Processor Information ROM Format ...................................................................41
Current Address Read SMBus Packet ................................................................43
Random Address Read SMBus Packet ..............................................................43
7
Pentium® III Xeon™ Processor at 500 and 550 MHz
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
51
8
Byte Write SMBus Packet ...................................................................................43
Write Byte SMBus Packet ...................................................................................45
Read Byte SMBus Packet...................................................................................45
Send Byte SMBus Packet ...................................................................................45
Receive Byte SMBus Packet ..............................................................................45
ARA SMBus Packet ............................................................................................45
Command Byte Bit Assignments.........................................................................45
Thermal Sensor Status Register .........................................................................47
Thermal Sensor Configuration Register..............................................................47
Thermal Sensor Conversion Rate Register ........................................................48
Thermal Sensor SMBus Addressing on the Pentium® III Xeon™ Processor...... 49
Memory Device SMBus Addressing on the Pentium® III Xeon™ Processor ...... 49
Thermal Design Power .......................................................................................51
Example Thermal Solution Performance at Thermal Plate Power of 50 Watts... 52
Signal Listing in Order by Pin Number ................................................................62
Signal Listing in Order by Pin Name ...................................................................66
Boxed Processor Heatsink Dimensions ..............................................................73
Fan/Heatsink Power and Signal Specifications................................................... 78
Debug Port Pinout Description and Requirements ............................................. 80
BR[3:0]# Signals Rotating Interconnect, 4-Way System..................................... 89
BR[3:0]# Signals Rotating Interconnect, 2-Way System..................................... 89
Agent ID Configuration........................................................................................89
Output Signals ....................................................................................................98
Input Signals1 .....................................................................................................99
I/O Signals (Single Driver).................................................................................100
I/O Signals (Multiple Driver) ..............................................................................100
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
1.0
Introduction
The Pentium III Xeon processor is a follow-on to the Pentium Pro and Pentium® II Xeon
processors. The Pentium III Xeon processor, like the Pentium Pro and Pentium II Xeon processors,
implements a Dynamic Execution micro-architecture — a unique combination of multiple branch
prediction, data flow analysis, and speculative execution. This enables Pentium III Xeon processors
to deliver higher performance than the Pentium® processor, while maintaining binary compatibility
with all previous Intel Architecture processors. The Pentium III Xeon processor is available in
512K, 1MB, and 2MB L2 cache options.
The Pentium III Xeon processor, like the Pentium II Xeon processor, executes MMX technology
instructions for enhanced media and communication performance. In addition, the Pentium® III
processor executes Streaming SIMD Extensions for enhanced floating point and 3-D application
performance.The Pentium III Xeon processor also utilizes the Single Edge Contact Cartridge
(S.E.C.C.) package technology first introduced on the Pentium® II processor. This packaging
technology allows Pentium III Xeon processors to implement the Dual Independent Bus
Architecture and have up to 2-MBytes of level 2 cache. Like the Pentium Pro and Pentium II Xeon
processors, level 2 cache communication occurs at the full speed of the processor core. The
Pentium III Xeon processor extends the concept of processor identification with the addition of a
processor serial number. Refer to the Intel® Processor Serial Number for more detailed
information on the implementation of the Intel processor serial number. A significant feature of the
Pentium III Xeon processor, from a system perspective, is the built-in direct multiprocessing
support. For systems with up to four processors, it is important to consider the additional power
burdens and signal integrity issues of supporting multiple loads on a high-speed bus. The Pentium
III Xeon processor supports both uniprocessor and multiprocessor implementations with up to four
processor on each local processor bus, or system bus.
The Pentium III Xeon processor system bus operates using GTL+ signaling levels with a new type
of buffer utilizing active negation and multiple terminations. This new bus logic is called Assisted
Gunning Transistor Logic, or AGTL+. The Pentium III Xeon processors also deviate from the
Pentium Pro processor in implementing an S.E.C. cartridge package supported by the 330-Contact
Slot Connector (SC330). (See Section 6.0 for the processor mechanical specifications.) This
document provides information to allow the user to design a system using Pentium III Xeon
processors.
1.1
Terminology
In this document, a ‘#’ symbol after a signal name refers to an active low signal. This means that a
signal is in the active state (based on the name of the signal) when driven to a low level. For
example, when FLUSH# is low, a flush has been requested. When NMI is high, a nonmaskable
interrupt has occurred. In the case of lines where the name does not imply an active state but
describes part of a binary sequence (such as address or data), the ‘#’ symbol implies that the signal
is inverted. For example, D[3:0] = ‘HLHL’ refers to a hex ‘A’, and D [3:0] # = ‘LHLH’ also refers
to a hex ‘A’ (H= High logic level, L= Low logic level).
The term ‘system bus’ refers to the interface between the processor, system core logic and other
bus agents. The system bus is a multiprocessing interface to processors, memory and I/O. The term
‘cache bus’ refers to the interface between the processor and the L2 cache. The cache bus does
NOT connect to the system bus, and is not accessible by other agents on the system bus. Cache
coherency is maintained with other agents on the system bus through the MESI cache protocol as
supported by the HIT# and HITM# bus signals.
Datasheet
9
Pentium® III Xeon™ Processor at 500 and 550 MHz
The term “Pentium III Xeon processor” refers to the cartridge package which interfaces to a host
system board through a SC330 Connector. Pentium III Xeon processors include a processor core, a
level 2 cache, system bus termination and various system management features. The Pentium III
Xeon processor includes a thermal plate for cooling solution attachment and a protective cover.
1.1.1
S.E.C. Cartridge Terminology
The following terms are used often in this document and are explained here for clarification:
• Cover — The processor casing on the opposite side of the thermal plate.
• Pentium® III Xeon™ processor — The 100 MHz SC330 product including internal
components, substrate, thermal plate and cover.
• L1 cache — Integrated static RAM used to maintain recently used information. Due to code
locality, maintaining recently used information can significantly improve system performance
in many applications. The L1 cache is integrated directly on the processor core.
• L2 cache —The L2 cache increases the total cache size significantly through the use of
multiple components.
• Processor substrate — The structure on which components are mounted inside the S.E.C.
cartridge (with or without components attached).
• Processor core — The processor’s execution engine.
• S.E.C. cartridge — The processor packaging technology used by the Pentium III Xeon
processor. S.E.C. is short for “Single Edge Contact” cartridge.
• Thermal plate — The surface used to connect a heatsink or other thermal solution to the
processor.
Additional terms referred to in this and other related documentation:
• Slot 2 — Former nomenclature for the connector that the S.E.C. cartridge plugs into, just as
the Pentium® Pro processor uses Socket . Now called 330-Contact Slot Connector (SC330).
• Retention mechanism — A mechanical component designed to hold the processor in a
SC330 connector.
• SC330 — Abbreviation for the 330-Contact Slot Connector that the S.E.C. cartridge plugs
into, just as the Pentium Pro processor uses Socket .
1.2
References
The reader of this specification should also be familiar with material and concepts presented in the
following documents:
• AP-586, Pentium® II Processor Thermal Design Guidelines (Order Number 243331)
• CPU-ID Instruction application note (Order Number 241618)
• Pentium® III Xeon™ Processor I/O Buffer Models, Viewlogic* XTK* (formally Quad) Format
(Electronic Form)
• Pentium® III Xeon™ Processor Power Distribution Guidelines (Order Number 245095)
• Pentium® III Xeon™ Processor Specification Update (Order Number 244460)
10
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
• Pentium® II Xeon™ Processor Support Component Vendor List (http://developer.intel.com/
design/pentiumii/xeon/components/)
• Intel Architecture Software Developer's Manual (Order Number 243193)
— Volume I: Basic Architecture (Order Number 243190)
— Volume II: Instruction Set Reference (Order Number 243191)
— Volume III: System Programming Guide (Order Number 243192)
•
•
•
•
•
330-Contact Slot Connector (SC330) Design Guidelines (Order Number 244428)
VRM 8.2 DC–DC Converter Design Guidelines (www.developer.intel.com)
VRM 8.3 DC–DC Converter Design Guidelines, rev 1.0 (Order Number 243870)
Intel® Pentium® III Processor Bus Terminator Design Guidelines (Order Number 245099)
Pentium® III Xeon™ Processor/Intel ® 450NX PCIset AGTL+ Layout Guidelines (Order
Number 245097)
• 100 MHz 2-Way SMP Pentium ® III Xeon™ Processor/Intel ® 440GX AGPset AGTL+ Layout
Guidelines (Order Number 245096)
• P6 Family of Processors Hardware Developer's Manual (Order Number 244001)
• Pentium® II Processor Developer’s Manual (Order Number 243502)
• Pentium® III Xeon™ Processor SMBus Thermal Reference Guidelines (Order Number
245098)
• Intel® Processor Serial Number (Order Number 245119)
Most or all of this documentation can be found on Intel’s developer’s world wide web site:
www.developer.intel.com.
2.0
Electrical Specifications
2.1
The Pentium® III Xeon™ Processor System Bus and V REF
Most Pentium III Xeon processor signals use a variation of the Pentium Pro processor GTL+
signaling technology. The Pentium III Xeon processor differs from the Pentium Pro processor in its
output buffer implementation. The buffers that drive most of the system bus signals on the Pentium
III Xeon processor are actively driven to CCCORE for one clock cycle after the low to high
transition to improve rise-times and reduce noise. These signals should still be considered opendrain and require termination to a supply that provides the high signal level. Because this
specification is different from the GTL+ specification, it is referred to as Assisted Gunning
Transistor Logic (AGTL+) in this document. AGTL+ logic and GTL+ logic are compatible with
each other and may both be used on the same system bus. Also refer to the Pentium® II Processor
Developer’s Manual for the GTL+ buffer specification.
AGTL+ inputs use differential receivers which require a reference signal (VREF). VREF is used by
the receivers to determine if a signal is a logical 0 or a logical 1. The Pentium III Xeon processor
generates its own version of VREF. VREF must be generated on the baseboard for other devices on
the AGTL+ system bus. Termination is used to pull the bus up to the high voltage level and to
control signal integrity on the transmission line. The processor contains termination resistors that
Datasheet
11
Pentium® III Xeon™ Processor at 500 and 550 MHz
provide termination for each Pentium III Xeon processor. These specifications assume the
equivalent of 6 AGTL+ loads and termination resistors to ensure the proper timings on rising and
falling edges. See test conditions described with each specification.
Due to the existence of termination on each of up to 4 processors in a Pentium III Xeon processor
system, the AGTL+ bus is typically not a daisy chain topology as in previous P6 family processor
systems. Also new to Pentium III Xeon processors, timing specifications are defined to points
internal to the processor packaging. Analog signal simulation of the system bus is required when
developing Pentium III Xeon processor based systems to ensure proper operation over all
conditions. Pentium® III Xeon™ Processor I/O Buffer Models are available for simulation.
The 100 MHz 2-Way SMP Pentium® III Xeon™ Processor/Intel® 440GX AGPset AGTL+ Layout
Guidelines and Pentium® III Xeon™ Processor/Intel® 450NX PCIset AGTL+ Layout Guidelines
contain information on possible layout topologies and other information for analog simulation.
2.2
Power and Ground Pins
The operating voltage of the processor core and of the L2 cache die differ from each other. There
are two groups of power inputs on the Pentium III Xeon processor package to support this voltage
difference between the components in the package. There are also five pins defined on the package
for core voltage identification (VID_CORE), and five pins defined on the package for L2 cache
voltage identification (VID_L2). These pins specify the voltage required by the processor core and
L2 cache respectively. These have been added to cleanly support voltage specification variations on
current and future Pentium III Xeon processors.
For signal integrity improvement and clean power distribution within the S.E.C. package, Pentium
III Xeon processors have 67 VCC (power) and 56 VSS (ground) inputs. The 67 VCC pins are further
divided to provide the different voltage levels to the components. VCCCORE inputs for the processor
core account for 35 of the VCC pins, while 8 VTT inputs (1.5 V) are used to provide an AGTL+
termination voltage to the processor and 20 VCCL2 inputs are for use by the L2 cache. One
VCCSMBUS pin is provided for use by the SMBus and one VCCTAP for the test access port.
VCCSMBUS, VCCL2, and VCCCORE must remain electrically separated from each other. On the
circuit board, all VCCCORE pins must be connected to a voltage island and all VCCL2 pins must be
connected to a separate voltage island (an island is a portion of a power plane that has been divided,
or an entire plane). Similarly, all VSS pins must be connected to a system ground plane.
2.3
Decoupling Guidelines
Due to the large number of transistors and high internal clock speeds, the processor is capable of
generating large average current swings between low and full power states. This causes voltages on
power planes to sag below their nominal values if bulk decoupling is not adequate. Care must be
taken in the board design to ensure that the voltage provided to the processor remains within the
specifications listed in Table 5. Failure to do so can result in timing violations or a reduced lifetime
of the component.
2.3.1
Pentium® III Xeon™ Processor VCCCORE
Regulator solutions must provide bulk capacitance with a low Effective Series Resistance (ESR)
and the system designer must also control the interconnect resistance from the regulator (or VRM
pins) to the SC330 connector. Simulation is required. Bulk decoupling for the large current swings
12
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
when the part is powering on, or entering/exiting low power states, is provided on the voltage
regulation module (VRM) defined in the VRM 8.2 DC–DC Converter Design Guidelines and the
VRM 8.3 DC–DC Converter Design Guidelines. The input to VCCCORE should be capable of
delivering a recommended minimum dICCCORE/dt defined in Table 6 while maintaining the
required tolerances defined in Table 5. See the Pentium® III Xeon™ Processor Power Distribution
Guidelines.
2.3.2
Level 2 Cache Decoupling
Regulator solutions need to provide bulk capacitance with a low Effective Series Resistance (ESR)
in order to meet the tolerance requirements for VCCL2. Use similar design practices as those
recommended for VCCCORE. See the Pentium® III Xeon™ Processor Power Distribution
Guidelines.
2.3.3
System Bus AGTL+ Decoupling
The Pentium III Xeon processor contains high frequency decoupling capacitance on the processor
substrate; bulk decoupling must be provided for by the system baseboard for proper AGTL+ bus
operation. High frequency decoupling may be necessary at the SC330 connector to further improve
signal integrity if noise is picked up at the connector interface. See the Pentium® III Xeon™
Processor Power Distribution Guidelines.
2.4
System Bus Clock and Processor Clocking
The BCLK input directly controls the operating speed of the system bus interface. All system bus
timing parameters are specified with respect to the rising edge of the BCLK input, measured at the
processor core. The Pentium III Xeon processor core frequency must be configured during Reset by
using the A20M#, IGNNE#, LINT[1]/NMI, and LINT[0]/INTR pins (see Table 1). The value on
these pins during Reset determines the multiplier that the Phase Lock Loop (PLL) will use for the
internal core clock. See the P6 Family of Processors Hardware Developer's Manual for the
definition of these pins during reset and the operation of the pins after reset.
Note:
The frequency multipliers supported are shown in Table 1; other combinations will not be validated
nor supported by Intel. Also, each multiplier is only valid for use on the product of the frequency
indicated in Table 1.
Clock multiplying within the processor is provided by the internal PLL, requiring a constant
frequency BCLK input. The BCLK frequency ratio cannot be changed dynamically during normal
operation or any low power modes. The BCLK frequency ratio can be changed when RESET# is
active, assuming that all Reset specifications are met.
Table 1.
Datasheet
Core Frequency to System Bus Multiplier Configuration
Multiplication of Processor
Core Frequency to System
Bus Frequency
Product Supported
on
LINT[1]
LINT[0]
A20M#
IGNNE#
1/2
Reset only
L
L
L
L
1/3
Not Supported
L
L
L
H
1/4
Not Supported
L
L
H
L
1/5
500, 550 MHz
L
L
H
H
13
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 1.
Core Frequency to System Bus Multiplier Configuration
Multiplication of Processor
Core Frequency to System
Bus Frequency
Product Supported
on
LINT[1]
LINT[0]
A20M#
IGNNE#
2/5
Not Supported
L
H
L
L
2/7
Not Supported
L
H
L
H
2/9
Not Supported
L
H
H
L
2/11
550 MH
L
H
H
H
1/6
Not Supported
H
L
L
L
1/7
Not Supported
H
L
L
H
1/8
Not Supported
H
L
H
L
Reserved
Not Supported
H
L
H
H
2/13
Not Supported
H
H
L
L
2/15
Not Supported
H
H
L
H
2/3
Not Supported
H
H
H
L
1/2
Reset Only
H
H
H
H
See Figure 1 for the timing relationship between the system bus multiplier signals, RESET#, and
normal processor operation. Using CRESET# (CMOS Reset) and the timing shown in Figure 1, the
circuit in Figure 2 can be used to share these configuration signals. The component used as the
multiplexer must not have outputs that drive higher th an 2.5V in order to meet the processor’s
2.5 V tolerant buffer specifications. The multiplexer output current should be limited to 200mA
maximum, in case the VCCCORE supply to the processor ever fails.
As shown in Figure 2, the pull-up resistors between the multiplexer and the processor (1 kΩ) force
a “safe” ratio into the processor in the event that the processor powers up before the multiplexer
and/or core logic. This prevents the processor from ever seeing a ratio higher than the final ratio.
If the multiplexer were powered by CC2.5, a pull-down resistor could be used on CRESET#
instead of the four pull-up resistors between the multiplexer and the Pentium III Xeon processors.
In this case, the multiplexer must be designed such that the compatibility inputs are truly ignored,
as their state is unknown.
In any case, the compatibility inputs to the multiplexer must meet the input specifications of the
multiplexer. This may require a level translation before the multiplexer inputs unless the inputs and
the signals driving them are already compatible.
For FRC mode operation, these inputs to the processor must be synchronized using BCLK to meet
setup and hold times to the processors. This may require the use of high-speed programmable
logic.
14
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Figure 1. Timing Diagram of Clock Ratio Signals
BCLK
RESET#
CRESET#
≤ Final Ratio
Ratio Pins#
Compatibility
Final Ratio
Figure 2. Logical Schematic for Clock Ratio Pin Sharing
2.5 V
2.5 V
1K Ω
Mux
A20M#
1-4
Processors
IGNNE#
LINT1/NMI
LINT0/INTR
Set Ratio:
CRESET#
Note:
2.4.1
Signal Integrity issues may require this circuit to be modified.
Mixing Processors
Mixing components of different internal clock frequencies is not supported and has not been
validated by Intel. Operating system support for MP with mixed frequency components should also
be considered.
Also, Intel does not support or validate operation of processors with different cache sizes. Intel
only supports and validates multi-processor configurations where all processors operate with the
same system bus and core frequencies and have the same L1 and L2 cache sizes. Pentium III Xeon
processors with different cache components, but the same cache size are validated and supported.
Similarly, Intel does not support or validate the mixing of Pentium III Xeon processors and Pentium
II Xeon processors in the same system bus, regardless of frequency or L2 cache sizes.
Datasheet
15
Pentium® III Xeon™ Processor at 500 and 550 MHz
2.5
Voltage Identification
The Pentium III Xeon processor contains five voltage identification pins for core voltage selection
and five voltage identification pins for L2 cache voltage selection. These pins may be used to
support automatic selection of both power supply voltages. VID_CORE[4:0] controls the voltage
supply to the processor core and VID_L2[4:0] controls the voltage supply to the L2 cache. Both
use the same encoding as shown in Table 2. They are not driven signals, but are either an open
circuit or a short circuit to VSS. The combination of opens and shorts defines the voltage required
by the processor core and L2 cache. The VID pins support variations in processor core voltage
specifications and in L2 cache implementations among processors in the Pentium III Xeon
processor family. Table 2 shows the recommended range of values to support for both the processor
core and the L2 cache. A ‘1’ in this table refers to an open pin and ‘0’ refers to a short to ground.
The definition provided below is a superset of the definition previously defined for the Pentium Pro
processor (VID4 was not used by the Pentium Pro processor) and is common to the Pentium II,
Pentium II Xeon processor, and Pentium III Xeon processors. The power supply must supply the
voltage that is requested or it must disable itself.
To ensure the system is ready for all Pentium III Xeon processors, a system should support those
voltages indicated with a bold x in Table 2. Supporting a smaller range will risk the ability of the
system to migrate to possible higher performance processors in the future. Support for a wider
range provides more flexibility and is acceptable.
Table 2.
Core and L2 Voltage Identification Definition 1, 2 (Sheet 1 of 2)
Processor Pins
Core3
L23
1.80
x
x
0
1.85
x
x
1
1
1.90
x
x
0
1
0
1.95
x
x
0
0
1
2.00
x
x
0
0
0
0
2.05
x
x
1
1
1
1
0
2.1
x
x
1
1
1
0
1
2.2
x
1
1
1
0
0
2.3
x
1
1
0
1
1
2.4
x
1
1
0
1
0
2.5
x
1
1
0
0
1
2.6
x
1
1
0
0
0
2.7
x
1
0
1
1
1
2.8
x
1
0
1
1
0
2.9
1
0
1
0
1
3.0
1
0
1
0
0
3.1
1
0
0
1
1
3.2
1
0
0
1
0
3.3
VID4
VID3
VID2
VID1
VID0
0
0
1
0
1
0
0
1
0
0
0
0
0
0
0
0
0
00110b - 01111b
16
VCC
Reserved
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 2.
Core and L2 Voltage Identification Definition
1, 2
(Sheet 2 of 2)
Processor Pins
VID4
VID3
VID2
VID1
VID0
VCC
1
0
0
0
1
3.4
1
0
0
0
0
3.5
1
1
1
1
1
no core
Core3
L23
NOTES
1. 0 = Processor pin connected to VSS, 1 = Open on processor; may be pulled up to TTL VIH on baseboard. See
the VRM 8.2 DC–DC Converter Design Guidelines and/or the VRM 8.3 DC–DC Converter Design
Guidelines.
2. VRM output should be disabled for V CCCORE values less than 1.80V.
3. x = Required
Note:
The ‘11111’ (all opens) ID can be used to detect the absence of a processor core in a given slot as
long as the power supply used does not affect these lines. Detection logic and pull-ups should not
affect VID inputs at the power source. (See Section 9.0.)
The VID pins should be pulled up to a TTL-compatible level with external resistors to the power
source of the regulator only if required by the regulator or external logic monitoring the VID[4:0]
signals. The power source chosen must be guaranteed to be stable whenever the supply to the
voltage regulator is stable. This will prevent the possibility of the processor supply going above
VCCCORE in the event of a failure in the supply for the VID lines. In the case of a DC-to-DC
converter, this can be accomplished by using the input voltage to the converter for the VID line
pull-ups. A resistor of greater than or equal to 10 kΩ may be used to connect the VID signals to the
converter input. See the VRM 8.2 DC–DC Converter Design Guidelines and/or VRM 8.3 DC–DC
Converter Design Guidelines for further information.
2.6
System Bus Unused Pins and Test Pins
All RESERVED_XXX pins must remain unconnected. Connection of RESERVED_XXX pins to
VCCCORE, VCCL2, VSS, VTT, to each other, or to any other signal can result in component
malfunction or incompatibility with future members of the Pentium III Xeon processor family. See
Section 6.0 for a pin listing of the processor edge connector for the location of each reserved pin.
The TEST_25_A62 pin must be connected to 2.5V via a pull-up resistor of between 1 kΩ and 10
kΩ. TEST_VCC_CORE must each be connected individually to VCCCORE through a ~10 kΩ
(approximately) resistor. TEST_VTT pins must each be connected individually to VTT with a
~150Ω resistor. TEST_VSS pins must each be connected individually to SS with a ~1kΩ resistor.
PICCLK must always be driven with a valid clock input, and the PICD[1:0] lines must be pulled-up
to 2.5 V even when the APIC will not be used. A separate pull-up resistor to 2 .5V (keep trace
short) is required for each PICD line.
For reliable operation, always connect unused inputs to an appropriate signal level. Unused
AGTL+ inputs should be left as no connects; AGTL+ termination on the processor provides a high
level. Unused active low CMOS inputs should be connected to 2.5V with a ~10 kΩ resistor.
Unused active high CMOS inputs should be connected to ground (VSS). Unused outputs may be
left unconnected. A resistor must be used when tying bi-directional signals to power or ground.
Datasheet
17
Pentium® III Xeon™ Processor at 500 and 550 MHz
When tying any signal to power or ground, a resistor will also allow for system testability. For
correct operation when using a logic analyzer interface, refer to Section 8.0 for design
considerations.
2.7
System Bus Signal Groups
In order to simplify the following discussion, the system bus signals have been combined into
groups by buffer type. All system bus outputs should be treated as open drain and require a high
level source provided externally by the termination or pull-up resistor.
AGTL+ input signals have differential input buffers, which use 2/3 V TT as a reference level.
AGTL+ output signals require termination to 1.5V. I nthis document, the term “AGTL+ Input”
refers to the AGTL+ input group as well as the AGTL+ I/O group when receiving. Similarly,
“AGTL+ Output” refers to the AGTL+ output group as well as the AGTL+ I/O group when driving.
The AGTL+ buffers employ active negation for one clock cycle after assertion to improve rise
times.
The CMOS, Clock, APIC, and TAP inputs can each be driven from ground to 2.5V. The CMOS,
APIC, and TAP outputs are open drain and should be pulled high to 2.5V.This ensures not only
correct operation for current Pentium III Xeon processors, but compatibility for future Pentium III
Xeon processor products as well. There is no active negation on CMOS outputs. ~150Ω resistors
are expected on the PICD[1:0] lines. Timings are specified into the load resistance as defined in the
AC timing tables. See Section 8.0 for design considerations for debug equipment.
The SMBus signals should be driven using standard 3.3 V CMOS logic levels.
Table 3.
Pentium® III Xeon™ Processor System Bus Pin Groups
Group Name
AGTL+ Input
BPRI#, BR[3:1]#1, DEFER#, RESET#, RS[2:0]#, RSP#, TRDY#
AGTL+ Output
PRDY#
AGTL+ I/O
A[35:03]#, ADS#, AERR#, AP[1:0]#, BERR#, BINIT#, BNR#, BP[3:2]#, BPM[1:0]#, BR0#1,
D[63:00]#, DBSY#, DEP[7:0]#, DRDY#, FRCERR, HIT#, HITM#, LOCK#, REQ[4:0]#, RP#
CMOS Input
A20M#, FLUSH#, IGNNE#, INIT#, LINT0/INTR, LINT1/NMI, PREQ#, PWRGOOD2, SMI#,
SLP#2, STPCLK#
CMOS Output
FERR#, IERR#, THERMTRIP#2
System Bus
Clock
bclk
APIC Clock
picclk
APIC I/O
3
picd[1:0]
TAP Input
TAP Output
tck, tdi, tms, trst#
3
TDO
SMBus Interface
Power/Other
18
Signals
4
SMBDAT, SMBCLK, SMBALERT#, WP
VCCCORE, VCCL2, VCCTAP, V CCSMBUS, VID_L2[4:0], VID_CORE[4:0], VTT , VSS,
TEST_25_A62, TEST_VCC_CORE, TEST_VSS, PWR_EN[1:0] 2, RESERVED_XXX,
SA[2:0], SELFSB[1:0]
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
NOTES
1. The BR0# pin is the only BREQ# signal that is bi-directional. The internal BREQ# signals are mapped onto
BR# pins based on a processor’s agent ID. See Section 9.0 for more information.
2. For information on these signals, see Section 9.0.
3. These signals are specified fo r 2.5V operation.
4. VCCCORE is the power supply for the Pentium® III Xeon™ processor core.
VCCL2 is the power supply for the L2 cache memory.
VID_CORE[4:0], and VID_L2[4:0] pins are described in Table 2.
VTT is used for the AGTL+ termination.
VSS is system ground.
VCCTAP is theTAP supply.
VCCSMBUS is the SM bus supply.
Reserved pins must be left unconnected. Do not connect to each other.
Test Pins are described in Section 2.6.
Other signals are described in Section 9.0.
2.7.1
Asynchronous vs. Synchronous for System Bus Signals
All AGTL+ signals are synchronous to BCLK. All of the CMOS, Clock, APIC, and TAP signals
can be applied asynchronously to BCLK, except when running two processors as an FRC pair.
Synchronization logic is required on signals going to both processors in order to run in FRC mode.
The TAP logic can not be used while a processor is running in an FRC pair, and the TAP signals
should therefore be at the appropriate inactive levels for FRC operation.
Also note the timing requirements for FRC mode operation. With FRC enabled, PICCLK must be
1/4 the frequency of BCLK, synchronized with respect to BCLK, and must always lag BCLK as
specified in Table 15 and Figure 8.
All APIC signals are synchronous to PICCLK. All TAP signals are synchronous to TCK. All
SMBus signals are synchronous to SMBCLK. TCK and SMBCLK may always be asynchronous to
all other clocks.
2.8
Test Access Port (TAP) Connection
Depending on the voltage levels supported by other components in the Test Access Port (TAP)
logic, it is recommended that the Pentium III Xeon processors be first in the TAP chain and
followed by any other components within the system. A voltage translation buffer should be used to
drive the next device in the chain unless a 3 .3V o r 5V component is used that is capable of
accepting a 2.5V input. Similar considerations must be made for TCK, TMS, and TRST#.
Multiple copies of each TAP signal may be required if multiple voltage levels are needed within a
system.
Note:
TDI is pulled up to V CCTAP with ~150Ω on the Pentium III Xeon processor cartridge. An open
drain signal driving this pin must be able to deliver sufficient current to drive the signal low. Also,
no resistor should exist in the system design on this pin as it would be in parallel with this resistor
A Debug Port is described in Section 8.0. The Debug Port must be placed at the start and end of the
TAP chain with TDI to the first component coming from the Debug Port and TDO from the last
component going to the Debug Port. In an MP system, be cautious when including an empty
SC330 connector in the scan chain. All connectors in the scan chain must have a processor or
termination card installed to complete the chain between TDI and TDO or the system must support
a method to bypass the empty connectors; SC330 terminator substrates should tie TDI directly to
TDO. (See Section 8.0 for more details.)
Datasheet
19
Pentium® III Xeon™ Processor at 500 and 550 MHz
2.9
Maximum Rating
Table 4 contains Pentium III Xeon processor stress ratings. Functional operation at the absolute
maximum and minimum is not implied nor guaranteed. The processor should not receive a clock
while subjected to these conditions. Functional operating conditions are given in the AC and DC
tables. Extended exposure to the maximum ratings may affect device reliability. Furthermore,
although the processor contains protective circuitry to resist damage from static electric discharge,
one should always take precautions to avoid high static voltages or electric fields.
Table 4.
Pentium® III Xeon™ Processor Absolute Maximum Ratings
Symbol
Parameter
Min
Max
Unit
Notes
TSTORAGE
Processor storage temperature
–40
85
°C
VCCCORE
Processor core supply voltage with
respect to VSS
–0.5
Operating
voltage + 1.0
V
1
VCCL2
Any processor L2 supply voltage with
respect to VSS
–0.5
Operating
voltage + 1.0
V
1
VSMBUS
Any processor SM supply voltage with
respect to VSS
-0.3
Operating
voltage + 1.0
V
VCCTAP
Any processor TAP supply voltage with
respect to VSS
-0.3
3.3
V
1
VCCL2 –
VCCCORE
L2 supply voltage with respect to core
voltage.
-(Core
Operating
Voltage
L2 Operating
Voltage
V
1, 2
VinGTL
AGTL+ buffer DC input voltage with
respect to VSS
–0.3
VCCCORE +
0.7
V
VinCMOS
CMOS & APIC buffer DC input voltage
with respect to VSS
–0.3
3.3
V
VinSMBus
SMBus buffer DC input voltage with
respect to VSS
-0.1
6.0
V
IPWR_EN
Max PWR_EN[1:0] pin current
100
mA
IVID
Max VID pin current
5
mA
NOTES:
1. Operating voltage is the voltage to which the component is designed to operate. See Table 5.
2. This parameter specifies that the processor will not be immediately damaged by either supply being disabled.
2.10
Processor DC Specifications
The voltage and current specifications provided in Table 5 and Table 6 are defined at the processor
edge fingers. The processor signal DC specifications in Table 7, Table 8, and Table 9 are defined at
the Pentium III Xeon processor core. Each signal trace between the processor edge finger and the
processor core carries a small amount of current and has a finite resistance. The current produces a
voltage drop between the processor edge finger and the core. Simulations should therefore be run
versus these specifications to the processor core.
See Section 9.0 for the processor edge finger signal definitions and Table 3 for the signal grouping.
20
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Most of the signals on the Pentium III Xeon processor system bus are in the AGTL+ signal group.
These signals are specified to be terminated to VTT. The DC specifications for these signals are
listed in Table 7.
To ease connection with other devices, the Clock, CMOS, APIC, SMBus and TAP signals are
designed to interface at non-AGTL+ levels. The DC specifications for these pins are listed in Table
8 and Table 9.
Note:
Unless otherwise noted, each specification applies to all Pentium III Xeon processors. Where
differences exist between Pentium III Xeon processors, look for the table entries identified by
“FMB” in order to design a Flexible Mother Board (FMB) capable of accepting all types of
Pentium III Xeon processors.
Specifications are only valid while meeting specifications for case temperature, clock frequency
and input voltages. Care should be taken to read all notes associated with each parameter
Table 5.
Voltage Specifications 1
Symbol
VCCCORE
Parameter
Min
VCC for processor core FMB
Typ
Max
1.8-2.1
2.00
All products
Unit
Notes
V
2, 3, 4
2, 3, 4
VCCCORE
Tolerance,
Static
Processor core voltage static
tolerance at edge fingers
-0.085
0.085
V
7
VCCCORE
Tolerance,
Transient
Processor core voltage transient
tolerance at edge fingers
-0.130
0.130
V
7
VCCL2
VCC for second level cache FMB
1.8-2.8
V
3, 5
50 0MHz ,5 12KB
50 0MHz , 1MB
50 0MHz , 2MB
55 0MHz ,5 12KB
55 0MHz , 1MB
55 0MHz , 2MB
2.7
2.7
2.0
2.0
2.0
2.0
3, 5
3, 5
3, 5
3, 5
3, 5
3, 5
VCCL2
Tolerance,
Static
Static tolerance at edge fingers of
second level cache supply
-0.085
0.085
V
7
VCCL2
Tolerance,
Transient
Transient tolerance at edge fingers
of second level cache supply
-0.125
0.125
V
7
VTT
AGTL+ bus termination voltage
1.365
1.50
1.635
V
6
VCCSMBUS
SMBus supply voltage
3.135
3.3
3.465
V
3.3 V±5%
VCCTAP
TAP supply voltage
2.375
2.50
2.625
V
2.5 V±5%
NOTES
1. Unless otherwise noted, all specifications in this table apply to all processor frequencies and cache sizes.
“FMB” is a suggested design guideline for flexible baseboard design.
2. VCCCORE supplies the processor core. FMB refers to the range of possible set points to expect for future
Pentium® III Xeon™ processors.
3. These voltages are targets only. A variable voltage source should exist on systems in the event that a
different voltage is required. See Section 2.5 for more information.
4. Use the Typical Voltage specification along with the Tolerance specifications to provide correct voltage
regulation to the processor.
5. VCCL2 supplies the L2 cache. This parameter is measured at the processor edge fingers.
6. VTT must be held to 1.5V ±9%. It is recommended that VTT be held t o 1.5V ±3% while the Pentium III Xeon
processor system bus is idle. This parameter is measured at the processor edge fingers. The SC330
Datasheet
21
Pentium® III Xeon™ Processor at 500 and 550 MHz
connector is specified to have a pin self-inductance of 6.0 nH maximum, a pin-to-pin capacitance of 2 pF
(maximum at 1 MHz), and an average contact resistance over the 6 V TT pins of 15 mΩ maximum.
7. These are the tolerance requirements, ac ross a 20MHz bandwidth, at the processor edge fingers. The
requirements at the processor edge fingers account for voltage drops (and impedance discontinuities) at the
processor edge fingers and to the processor core. Voltage must return to within the static voltage
specification within 100 us after the transient event. The SC330 connector is specified to have a pin selfinductance of 6.0 nH maximum, a pin-to-pin capacitance of 2 pF (maximum at 1 MHz), and an average
contact resistance of 15 mΩ maximum in order to function with the Intel specified voltage regulator module
(VRM 8.2 or VRM 8.3). Contact Intel for testing details of these parameters. Not 100% tested. Specified by
design characterization.
1
Table 6.
Current Specifications 1
Symbol
ICCCORE
Parameter
ICC for processor core FMB
Min
Typ
1
50 0MHz
55 0MHz
ICCL2
Max
Unit
Notes
16.0
A
2, 5, 6, 7
14.0
15.4
ICC for second level cache FMB1
9.4
50 0MHz, 5 12KB
50 0MHz, 1MB
50 0MHz, 2MB
55 0MHz ,5 12KB
55 0MHz , 1MB
55 0MHz , 2MB
3.4
6.8
6.0
3.5
3.5
6.3
IVTT
Termination voltage supply current
ISGnt
ICC Stop Grant for processor core
ICCSLP
ICC Sleep for processor core
dlccCORE/dt
Core ICC slew rate
(at the SC330 connector pins
dlccL2/dt
Second level cache I CC slew rate
(at the SC330 connector pins
0
0.3
0
Termination current slew rate
(at the SC330 connector pins
ICCTAP
ICC for TAP power supply
ICCSMBUS
ICC for SMBus power supply
A
3, 6, 7
3, 6, 7
3, 6, 7
3, 6, 7
3, 6, 7
3, 6, 7
3, 6, 7
1.2
A
8
0.8
A
6, 9
0.2
A
6
20
A/µs
10, 11
A/µs
10
10
50 0MHz
55 0MHz
dlCCVTT/dt
2, 5, 6, 7
2, 5, 6, 7
5
3
10, 11
10, 11
A/µs
100
mA
10
mA
4, 11
NOTES:
1. Unless otherwise noted, all specifications in this table apply to all processor frequencies and cache sizes.
“FMB” is a suggested design guideline for flexible baseboard design.
2. ICCCORE supplies the processor core.
3. Use theTypical Voltage specification with the Tolerance specifications to provide correct voltage regulation to
the processor.
4. VTT must be held t o 1.5V ±9%. It is recommended that V TT be held t o 1.5V ±3% while the Pentium ® III
Xeon™ processor system bus is idle. This is measured at the processor edge fingers.
5. The typical ICCCORE measurements are an average current draw during the execution of Winstone* 96 under
the Windows* 95 operating system. These numbers are meant as a guideline only, not a guaranteed
specification. Actual measurements will vary based upon system environmental conditions and configuration.
6. Max ICC measurements are measured at V CC nominal voltage under maximum signal loading conditions.
7. Voltage regulators may be designed with a minimum equivalent internal resistance to ensure that the output
voltage, at maximum current output, is no greater than the nominal (i.e., typical) voltage level of V CCCORE
(VCCCORE_TYP). In this case, the maximum current level for the regulator, I CCCOR_REG, can be reduced from
the specified maximum current I CCCORE_MAX and is calculated by the equation:
ICCCORE_REG = ICCCORE_MAX × VCCCORE_TYP / (VCCCORE_TYP+ VCCCORE static tolerance)
8. This is the current required for a single Pentium III Xeon processor. A similar current is drawn through the
termination resistors of each load on the AGTL+ bus. V TT is decoupled on the S.E.C. cartridge such that
22
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
negative current flow due to the active pull-up to VCCCORE in the Pentium III Xeon processor will not be seen
at the processor fingers.
9. The current specified is also for AutoHALT state.
10.Maximum values are specified by design/characterization at nominal V CC and at the SC330 connector pins.
11.Based on simulation and averaged over the duration of any change in current. Use to compute the maximum
inductance tolerable and reaction time of the voltage regulator. This parameter is not tested.
Table 7.
AGTL+ Signal Groups, DC Specifications at the Processor Core
Symbol
Parameter
Min
Max
Unit
Notes
VIL
Input Low Voltage
-0.3
2/3 VTT -0.1 V
V
5
VIH
Input High Voltage
2/3 VTT +0.1 V
VCCCORE
V
1, 2, 5
RONN
nMOS On Resistance
12.5
W
6, 7
RONP
pMOS On Resistance
85
W
6
VOHTS
Output High Voltage Tri-state
VTT
V
1, 5
IL
Leakage Current
±100
µA
3
ILO
Output Leakage Current
±15
µA
4
NOTES
1. Processor core parameter correlated into a 25Ω resistor to a VTT of 1.5 V.
2. Excursions above VTT to VCCCORE are allowed.
3. (0 ≤ VIN ≤ VCCCORE + 5%).
4. (0 ≤ VOUT ≤ VCCCORE + 5%).
5. The processor core drives high for only one clock cycle. It then drives low or tri-states its outputs. V TT is
specified in Table 5.
6. Not 100% tested. Specified by design characterization.
7. This RON specification corresponds to a OL_MAX of 0.49 V when taken into an effective 25 ohm load to V TT
of 1.5 V.
Figure 3. I-V Curve for nMOS Device
0.12
0.1
IOL (A)
0.08
0.06
0.04
0.02
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
1.1
1.2
1.3
1.4
1.5
Vout (V)
Datasheet
23
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 8.
CMOS, TAP, Clock and APIC Signal Groups, DC Specifications at the Processor
Core
Symbol
Parameter
Min
Max
Unit
V
Notes
VIL
Input Low Voltage
-0.3
0.7
VIH
Input High Voltage
1.7
2.625
V
2.5 V + 5% maximum
VOL
Output Low Voltag
0.5
V
Measured at 24mA
VOH
Output High Voltage
2.625
V
All outputs are open-drai n to 2.5V + 5%
IOL
Output Low Current
24
mA
ILI
Input Leakage Current
±100
µA
1
ILO
Output Leakage
Current
±30
µA
2
NOTES:
1. (0 ≤ VIN ≤ 2.62 5V).
2. (0 ≤ VOUT ≤ 2.62 5V).
Table 9.
SMBus Signal Group, DC Specifications at the Processor Core
Symbol
Parameter
Min
Max
Unit
Notes
VIL
Input Low Voltage
-0.3
0.3 x
VCCSMBUS
V
VIH
Input High Voltage
0.7 x VCCSMBUS
3.465
V
VOL
Output Low Voltage
0.4
V
IOL
Output Low Current
3
mA
Except SMBALERT#
IOL2
Output Low Current
mA
SMBALERT#
ILI
Input Leakage Current
10
µA
ILO
Output Leakage
Current
10
µA
6
3.3 V + 5% maximum
†
† SMBALERT# is an open drain signal.
2.11
AGTL+ System Bus Specifications
Table 10 below lists parameters controlled within the Pentium III Xeon processor to be taken into
consideration during simulation. The valid high and low levels are determined by the input buffers
using a reference voltage (VREF) which is generated internally in the processor cartridge from VTT.
VREF should be set to the same level for other AGTL+ logic using a voltage divider on the
baseboard. It is important that the baseboard impedance be specified and held to a ±10% tolerance,
and that the intrinsic trace capacitance for the AGTL+ signal group traces is known and wellcontrolled. For more details on AGTL+, see the 100 MHz 2-Way SMP Pentium ® III Xeon™
Processor/Intel® 440GX AGPset AGTL+ Layout Guidelines and Pentium® III Xeon™ Processor/
Intel® 450NX PCIset AGTL+ Layout Guidelines. Also refer to the Pentium® II Processor
Developer’s Manual for the GTL+ buffer specification.
24
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 10. Pentium® III Xeon™ Processor Internal Parameters for the AGTL+ Bus
Symbol
Parameter
RTT
Termination Resistor
VREF
Bus Reference Voltage
Min
Typ
Max
Units
Notes
150
W
1
2/3 VTT
V
2
NOTES
1. The Pentium ® III Xeon™ processor contains 1% AGTL+ termination resistors at the end of the signal trace on
the processor substrate.
2. VREF is generated on the processor substrate.
2.12
System Bus AC Specifications
The system bus timings specified in this section are defined at the Pentium III Xeon processor core
pins unless otherwise noted. Timings are tested at the processor core during manufacturing.
Timings at the processor edge fingers are specified by design characterization. Information
regarding signal characteristics between the processor core pins and the processor edge fingers is
found in the Pentium® III Xeon™ Processor I/O Buffer Models, Viewlogic* XTK* Format. See
Section 9.0 for the Pentium III Xeon processor edge connector signal definitions.
Note:
Timing specifications T45-T49 are reserved for future use.
All system bus AC specifications for the AGTL+ signal group are relative to the rising edge of the
BCLK input. All AGTL+ timings are referenced to 2/3 VTT for both ‘0’ and ‘1’ logic levels unless
otherwise specified.
Table 11. System Bus AC Specifications (Clock) at the Processor Core
T#
Parameter
Min
Nom
Max
Unit
System Bus Frequency
90.00
100.0
100.20
MHz
1, 2, 3
System Bus Frequency
90.00
100.00
MHz
1, 2, 4
T1:
BCLK Period
9.98
11.11
ns
4
3, 5
T1:
BCLK Period
10.00
11.11
ns
4
4, 5
T2:
BCLK Period Stability
150
ps
4
6, 7, 8
T3:
BCLK High Time
2.5
ns
4
@>2.0 V
T4:
BCLK Low Time
2.5
ns
4
@<0.5 V
T5:
BCLK Rise Time
0.5
1.5
ns
4
(0.5 V–2.0 V) 9
T6:
BCLK Fall Time
0.5
1.5
ns
4
(2.0 V–0.5 V) 9
10.0
Figure
Notes
NOTES
1. Table 1 shows the supported ratios for each processor.
2. Minimum System Bus Frequency is not 100% tested. Specified by design characterization to allow lowe
speed system bus operation for up to 6 load systems.
3. Applies to 500MHz products.
4. Applies to 550MHz product.
5. The BCLK period allows a +0.3 ns tolerance for clock driver and routing variation. BCLK must be within
specification whenever PWRGOOD is asserted.
6. It is recommended that a clock driver be used that is designed to meet the period stability specification into a
test load of 10 to 20 pF. Cycle-to-cycle jitter should be measured on adjacent rising edges of BCLK crossing
1.25 V at the processor core. This cycle-to-cycle jitter present must be accounted for as a component of flight
time between the processor(s) and/or core logic components. Positive or negative jitter of up to 150 ps is
Datasheet
25
Pentium® III Xeon™ Processor at 500 and 550 MHz
allowed between adjacent cycles. Positive or negative jitter of up to 250 ps is tolerated, but will result in up to
100 ps of AGTL+ I/O and CMOS timing degradation (i.e., timing parameters T7-9 and T11-13 will all increase
by 100 ps). Thus a system with jitter of 250 ps would need flight times that are 300 ps (100 ps additional jitter
+ 100 ps I/O timing degradation for both the source and receiver) better than a system with jitter of 150 ps.
7. The clock driver's closed loop jitter bandwidth should be less than 500 kHz (at -20dB). The bandwidth must
be set low to allow cascade connected PLL-based devices to track clock drivers with the specified jitter.
Therefore the bandwidth of the clock driver's output frequency-attenuation plot should be less than 500 kHz
measured at the -20 dB attenuation point. The test load should be 10 to 20 pF.
8. See the 100 MHz 2-Way SMP Pentium® III Xeon™ Processor/Intel® 440GX AGPset AGTL+ Layout
Guidelines or the Pentium® III Xeon™ Processor/Intel ® 450NX PCIset AGTL+ Layout Guidelines for
additional recommendations.
9. Not 100% tested. Specified by design characterization as a clock driver requirement.
Table 12. AGTL+ Signal Groups, System Bus AC Specifications at the Processor Core 1
RL = 25Ω Terminated to 1.5 V
T#
Parameter
Min
Max
Unit
Figure
Notes
T7:
AGTL+ Output Valid Delay
-0.07
2.7
ns
6
2
T8:
AGTL+ Input Setup Time
1.75
ns
7
3, 4, 5
T9:
AGTL+ Input Hold Time
0.62
ns
7
5
T10:
RESET# Pulse Width
1.00
ms
10
6
NOTES:
1. These specifications are tested during manufacturing.
2. Valid delay timings for these signals at the processor core are correlated into 25 W ter mination to 1.5V and
with VTT set to 1 .5V.
3. A minimum of 3 clocks must be guaranteed between two active-to-inactive transitions of TRDY#.
4. RESET# can be asserted (active) asynchronously, but must be deasserted synchronously.
5. The signal at the processor core must transition monotonically through the overdrive region (2/3 V TT ±
200mV).
6. After the bus ratio on A20M#, IGNNE# and LINT[1:0] are stable, V CCCORE, VCCL2 and BCLK are within
specification, and PWRGOOD is asserted. See Figure 10.
Table 13. CMOS, TAP, Clock and APIC Signal Groups, AC Specifications at the Processor
Core 1, 2
T#
Parameter
Min
Max
Unit
Figure
T11:
CMOS Output Valid Delay
1
8
ns
6
3
T12:
CMOS Input Setup Time
4
ns
7
4, 5
T13:
CMOS Input Hold Tim
1
ns
7
4
T14:
CMOS Input Pulse Width, except
PWRGOOD and LINT[1:0]
2
BCLKs
6
Active and Inactive states
6
BCLKs
5
6
BCLKs
6
11
7, 8
T14B: LINT[1:0] Input Pulse Width
T15:
PWRGOOD Inactive Pulse Width
10
Notes
NOTES:
1. These specifications are tested during manufacturing.
2. These signals may be driven asynchronously but must be driven synchronously in FRC mode
3. Valid delay timings for these signals are specified int o100W to 2.5V.
4. To ensure recognition on a specific clock, the setup and hold times with respect to BCLK must be met.
5. INTR and NMI are only valid when the local APIC is disabled. LINT[1:0] are only valid when the local APIC is
enabled.
6. This specification only applies when the APIC is enabled and the LINT1 or LINT0 pin is configured as an
edge triggered interrupt with fixed delivery, otherwise specification T14 applies.
7. When driven inactive or after V CCCORE, VCCL2 and BCLK become stable. PWRGOOD must remain below
VIL_MAX from Table 8 until all the voltage planes meet the voltage tolerance specifications i Table 5 and
26
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
BCLK has met the BCLK AC specifications in Table 11 for at least 10 clock cycles. PWRGOOD must rise
glitch-free and monotonica l y to 2.5V.
8. If the BCLK signal meets its AC specification withi n 150ns of turning on then the PWRGOOD Inactive Pulse
Width specification is waived and BCLK may start after PWRGOOD is asserted. PWRGOOD must still
remain below VIL_MAX until all the voltage planes meet the voltage tolerance specifications.
Table 14. System Bus AC Specifications (Reset Conditions)
T#
Parameter
Min
T16:
Reset Configuration Signals (A[14:05]#,
BR0#, FLUSH#, INIT#) Setup Time
4
T17:
Reset Configuration Signals (A[14:05]#,
BR0#, FLUSH#, INIT#) Hold Time
2
T18:
Reset Configuration Signals (A20M#,
IGNNE#, LINT[1:0]) Setup Time
1
T19:
Reset Configuration Signals (A20M#,
IGNNE#, LINT[1:0]) Delay Time
T20:
Reset Configuration Signals (A20M#,
IGNNE#, LINT[1:0]#) Hold Time
2
Max
Unit
Figure
Notes
BCLKs
10
Before deassertion of
RESET
BCLKs
10
After clock that
deasserts RESET#
ms
10
Before deassertion of
RESET#
5
BCLKs
10
After assertion of
RESET# †
20
BCLKs
10
11
After clock that
deasserts RESET#
20
† For a Reset, the clock ratio defined by these signals must be a safe value (their final or lower multiplier) within
this delay unless PWRGOOD is being driven inactive.
Table 15. System Bus AC Specifications (APIC Clock and APIC I/O) at the Processor Core
T#
Parameter
Min
Max
Unit
T21:
PICCLK Frequency
2.0
33.3
MHz
T21B: FRC Mode BCLK to PICCLK Offset
1.0
4.0
ns
T22:
PICCLK Period
30.0
500.0
ns
4
T23:
PICCLK High Time
12.0
ns
4
T24:
PICCLK Low Time
12.0
ns
4
T25:
PICCLK Rise Tim
0.25
3.0
ns
4
T26:
PICCLK Fall Time
0.25
3.0
ns
4
T27:
PICD[1:0] Setup Time
8.0
ns
7
3
T28:
PICD[1:0] Hold Time
2.5
ns
7
3
T29:
PICD[1:0] Valid Delay
1.5
ns
6
3, 4, 5
10.0
Figure
1
Notes
2
8
2
NOTE:
1. These specifications are tested during manufacturing.
2. With FRC enabled PICCLK must be 1/4 of BCLK and synchronized with respect to BCLK.
3. Referenced to PICCLK rising edge.
4. For open drain signals, valid delay is synonymous with float delay.
5. Valid delay timings for these signals are specif i ed to 2.5V.
Datasheet
27
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 16. System Bus AC Specifications (TAP Connection) at the Processor Core
Min
Max
Unit
16.667
MHz
1
T#
Parameter
Figure
Notes
T30:
TCK Frequency
T31:
TCK Period
60.0
ns
4
T32:
TCK High Time
25.0
ns
4
@1.7 V 2
T33:
TCK Low Time
25.0
ns
4
@0.7 V 2
T34:
TCK Rise Time
3.0
5.0
ns
4
(0.7 V–1. 7V) 2, 3
T35:
TCK Fall Time
3.0
5.0
ns
4
(1.7 V–0. 7V) 2, 3
T36:
TRST# Pulse Width
40.0
ns
12
Asynchronous
T37:
TDI, TMS Setup Time
5.0
ns
11
4
T38:
TDI, TMS Hold Tim
14.0
ns
11
4
T39:
TDO Valid Delay
1.0
10.0
ns
11
5, 6
25.0
ns
11
2, 5, 6
25.0
ns
11
5, 7, 8
25.0
ns
11
2, 5, 7, 8
T40:
TDO Float Dela
T41:
All Non-Test Outputs Valid Delay
T42:
All Non-Test Inputs Setup Time
T43:
All Non-Test Inputs Setup Time
5.0
ns
11
4, 7, 8
T44:
All Non-Test Inputs Hold Time
13.0
ns
11
4, 7, 8
2.0
2
NOTES:
1. Unless otherwise noted, these specifications are tested during manufacturing.
2. Not 100% tested. Specified by design characterization.
3. 1 ns can be added to the maximum TCK rise and fall times f or every 1MHz below 16.667MHz.
4. Referenced to TCK rising edge.
5. Referenced to TCK falling edge.
6. Valid delay timing for this signal is spec ified to 2.5V.
7. Non-Test Outputs and Inputs are the normal output or input signals (besides TCK, TRST#, TDI, TDO and
TMS). These timings correspond to the response of these signals due to TAP operations.
8. During Debug Port operation, use the normal specified timings rather than the TAP signal timings.
Table 17. SMBus Signal Group, AC Specifications at the Edge Fingers
†
28
T#
Parameter
Min
Max
Unit
100
KHz
Figure
T50:
SMBCLK Frequency
T51:
SMBCLK Period
10
µs
5
T52:
SMBCLK High Time
4.0
µs
5
T53:
SMBCLK Low Time
4.7
µs
5
T54:
SMBCLK Rise Time
1.0
µs
5
T55:
SMBCLK Fall Time
0.3
µs
5
T56:
SMBus Output Valid Delay
1.0
µs
6
T57:
SMBus Input Setup Time
ns
7
T58:
SMBus Input Hold Time
0
ns
7
T59:
Bus Free Time
4.7
µs
250
Notes
†
Minimum time allowed between request cycles.
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Figure 4 through Figure 12 are to be used in conjunction with the DC specification and AC timings
tables.
Figure 4. BCLK, PICCLK, TCK Generic Clock Waveform
Tr
Th
2.0 V
1.25 V
Clock
0.5 V
Tf
Tl
Tp
Tr = T5, T25, T34 (Rise Time)
Tf = T6, T26, T36 (Fall Time)
Th = T3, T23, T32 (High Time)
Tl = T4, T24, T33 (Low Time)
Tp = T1, T22, T31 (BCLK, PICCLK, TCK, Period)
Figure 5. SMBCLK Clock Waveform
Th
Tr
2.97V
2.46V
0.84V
SCLK
0.84V
Tf
Tl
Tr = T54
Tf = T55
Th = T52
Tl = T53
Figure 6. Valid Delay Timings
Clock
Tx
Signal
Tx
V
Valid
Valid
Tpw
Tx
= T7, T11, T29 (Valid Delay)
Tpw = T14, T15 (Pulse Wdith)
V
Datasheet
= 2/3 V
TT
for GTL+ signal group; 1.25V for CMOS, and APIC signal groups
29
Pentium® III Xeon™ Processor at 500 and 550 MHz
Figure 7. Setup and Hold Timings
Clock
Vclk
Ts
Signal
Th
V Valid
Ts = T8, T12, T27 (Setup Time)
Th = T9, T13, T28 (Hold Time)
V = 2/3 VTT for the AGTL+ signal group; 1.25V for the CMOS, and APIC signal groups
Vclk = 1.25V for BCLK, and PICCLK
Figure 8. FRC Mode BCLK to PICCLK Timing
BCLK
1.25 V
Lag
PICCLK
1.25 V
Lag = T21B (FRC Mode BCLK to PICCLK offset)
30
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Figure 9. System Bus Reset and Configuration Timings
BCLK
Tu
Tt
RESET#
Tv
Configuration
(A20M#, IGNNE#,
LINT[1:0])
Ty
Tz
Tx
Safe
Valid
Tw
Configuration
(A[14:5]#, BR0#,
FLUSH#, INIT#)
Valid
Tt = T9 (GTL+ Input Hold Time)
Tu = T8 (GTL+ Input Setup Time)
Tv = T10 (RESET# Pulse Width)
Tw = T16 (Reset Configuration Signals (A[14:5]#, BR0#, FLUSH#, INIT#) Setup Time)
Tx = T17 (Reset Configuration Signals (A[14:5]#, BR0#, FLUSH#, INIT#) Hold Time)
T20 (Reset Configuration Signals (A20M#, IGNNE#, LINT[1:0]) Hold Time)
Ty = T19 (Reset Configuration Signals (A20M#, IGNNE#, LINT[1:0]) Delay Time)
Tz = T18 (Reset Configuration Signals (A20M#, IGNNE#, LINT[1:0]) Setup Time)
Figure 10. Power-On Reset and Configuration Timings
BCLK
VCC
CORE
VTT
VCC
L2
VCC
2.5
PWRGOOD
Ta
Tb
RESET#
Tc
Configuration
(A20M#, IGNNE#,
LINT[1:0])
Valid Ratio
Ta = T15 (PWRGOOD Inactive Pulse Width)
Tb = T10 (RESET# Pulse Width)
Tc = T20 (Reset Configuration Signals (A20M#, IGNNE#, LINT[1:0]) Hold Time)
Datasheet
31
Pentium® III Xeon™ Processor at 500 and 550 MHz
Figure 11. Test Timings (Boundary Scan)
1.25V
TCK
Tv
Tw
Tr
Ts
1.25V
TDI, TMS
Non-Test
Input
Signals
Tx
Tu
Ty
Tz
TDO
Non-Test
Output
Signals
Tr = T43 (All Non-Test Inputs Setup Time)
Ts = T44 (All Non-Test Inputs Hold Time)
Tu = T40 (TDO Float Delay)
Tv = T37 (TDI, TMS Setup Time)
Tw = T38 (TDI, TMS Hold Time)
Tx = T39 (TDO Valid Delay)
Ty = T41 (All Non-Test Outputs Valid Delay)
Tz = T42 (All Non-Test Outputs Float Delay)
Figure 12. Test Reset Timings
1.25V
TRST#
Tq
Tq = T36 (TRST# Pulse Width)
3.0
Signal Quality
Signals driven on the Pentium III Xeon processor system bus should meet signal quality
specifications to ensure that the components read data properly and to ensure that incoming signals
do not affect the long term reliability of the component. Specifications are provided for simulation
at the processor core. Meeting the specifications at the processor core in Table 18 through Table 22
ensures that signal quality effects will not adversely affect processor operation.
32
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
3.1
System Bus Clock Signal Quality Specifications
Table 18 describes the signal quality specifications at the processor core pad for the Pentium III
Xeon processor system bus clock (BCLK) signal. Figure 13 shows the signal quality waveform for
the system bus clock at the processor core pads. Please see Table 11 for the definition of T numbers
and Table 18 for the definition of V numbers.
Table 18. BCLK Signal Quality Specifications for Simulation at the Processor Core
V#
Parameter
Min
V1:
BCLK VIL
V2:
BCLK VIH
1.7
V3:
VIN Absolute Voltage Range
–0.7
V4:
Rising Edge Ringback
1.7
V5:
Falling Edge Ringback
Nom
1
Max
Unit
Figure
0.7
V
13
V
13
V
13
V
13
2
V
13
2
3.3
0.7
Notes
NOTES
1. Unless otherwise noted, all specifications in this table apply to all Pentium® III Xeon™ processor frequencies
and cache sizes.
2. The rising and falling edge ringback voltage specified is the minimum (rising) or maximum (falling) absolute
voltage the BCLK signal can dip back to after passing the V IH (rising) or VIL (falling) voltage limits. This
specification is an absolute value.
Figure 13. BCLK, TCK, PICCLK Generic Clock Waveform at the Processor Core Pins
T3
V3
V4
V2
V1
V5
T6
3.2
V3
T4
T5
AGTL+ Signal Quality Specifications
Many scenarios have been simulated to generate a set of AGTL+ layout guidelines which are
available in the 100 MHz 2-Way SMP Pentium® III Xeon™ Processor/Intel ® 440GX AGPset
AGTL+ Layout Guidelines and Pentium® III Xeon™ Processor/Intel ® 450NX PCIset AGTL+
Layout Guidelines. Also refer to the Pentium® II Processor Developer’s Manual for the
specification for the GTL+ buffer specification.
Datasheet
33
Pentium® III Xeon™ Processor at 500 and 550 MHz
3.2.1
AGTL+ Ringback Tolerance Specifications
Table 19 provides the AGTL+ signal quality specifications for Pentium III Xeon processors for use
in simulating signal quality at the processor core pads. Figure 14 describes the signal quality
waveform for AGTL+ signals at the processor core pads. For more information on the AGTL+
interface, see the Pentiu ® II Processor Developer’s Manual.
Table 19. AGTL+ Signal Groups Ringback Tolerance Specifications at the Processor Core
1, 2, 3
T#
Parameter
Min
Unit
Figure
α:
Overshoot
100
mV
14
τ:
Minimum Time at High
0.50
ns
14
ρ:
Amplitude of Ringback
–20
mV
14
φ:
Final Settling Voltage
20
mV
14
δ:
Duration of Squarewave Ringback
N/A
ns
14
Notes
4, 5
NOTES:
1. Unless otherwise noted, all specifications in this table apply to all Pentium® III Xeon™ processor frequencies
and cache sizes.
2. Specifications are for the edge rate of 0.3 - 0.8 V/ns.
3. All values specified by design characterization.
4. Ringback below 2/3 VTT + 20 mV is not supported.
5. Intel recommends performing simulations using a r (rho) of -100 mV to allow margin for other sources of
system noise.
Figure 14. Low to High AGTL+ Receiver Ringback Tolerance
τ
α
2/3V TT +0.2
φ
2/3V TT
ρ
2/3V TT -0.2
δ
1.25V Clk Ref
Vstart
Clock
Time
Note: High to Low case is analogous.
3.2.2
AGTL+ Overshoot/Undershoot Guidelines
The overshoot/undershoot guideline limits transitions beyond V CC or VSS due to fast signal edge
rates. (Overshoot shown in Figure 15 for non-AGTL+ signals can also be applied to AGTL+
signals.) The processor can be damaged by repeated overshoot or undershoot events if great
enough. The overshoot/undershoot guideline is shown in Table 20.
34
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 20. AGTL+ Overshoot/Undershoot Guidelines at the Processor Core
3.3
Guideline
Transition
Signal Must Maintain
Unit
Figure
Overshoot
Undershoot
0→1
< 2.7
V
15
1→0
> -0.7
V
15
Non-AGTL+ Signal Quality Specifications
There are three signal quality parameters defined for non-AGTL+ signals: overshoot/undershoot,
ringback, and settling limit. All three signal quality parameters are shown in Figure 15 for the nonAGTL+ signal group at the processor core pads.
Figure 15. Non-AGTL+ Overshoot/Undershoot, Settling Limit, and Ringback
Overshoot
Settli ng L i mi t
V HI = V CC
2.5
Ri si ng-Edge
Ri ngback
V oltage
Fal l ing-Edge
Ri ngback
Settli ng L i mi t
VL O
VSS
T ime
U ndershoot
3.3.1
2.5 V Tolerant Buffer Overshoot/Undershoot Guidelines
The overshoot/undershoot guideline limits transitions beyond V CC or VSS due to fast signal edge
rates. (See Figure 15 for non-AGTL+ signals.) The processor can be damaged by repeated
overshoot or undershoot events on 2. 5V tolerant buffers if great enough. The overshoot/undershoot
guideline is shown in Table 21.
Table 21. 2.5 V Tolerant Signal Overshoot/Undershoot Guidelines at the Processor Core
3.3.2
Guideline
Transition
Signal Must Maintain
Unit
Figure
Overshoot
0→1
< 3.2
V
15
Undershoot
1→0
> -0.3
V
15
2.5 V Tolerant Buffer Ringback Specification
The ringback specification is the voltage at a receiving pin that a signal rings back to after
achieving its maximum absolute value. (See Figure 15 for an illustration of ringback.) Excessive
ringback can cause false signal detection or extend the propagation delay. Violations of the signal
ringback specification are not allowed for 2 .5V tolerant signals.
Table 22 shows signal ringback specifications for the 2 .5V tolerant signals to be used for
simulations at the processor core.
Datasheet
35
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 22. Signal Ringback Specifications fo r 2.5V Tolerant Signal Simulation at the
Processor Core
3.3.3
Input Signal Group
Transition
Maximum Ringback
(with Input Diodes Present)
Unit
Figure
Non-AGTL+ Signals
0→1
1.7
V
15
Non-AGTL+ Signals
1→0
0.7
V
15
2.5 V Tolerant Buffer Settling Limit Guideline
Settling limit defines the maximum amount of ringing at the receiving pin that a signal must reach
before its next transition. The amount allowed is 10% of the total signal swing (VHI – VLO) above
and below its final value. A signal should be within the settling limits of its final value, when either
in its high state or low state, before it transitions again.
Violation of the settling limit guideline is acceptable if simulations of 5 to 10 successive transitions
do not show the amplitude of the ringing increasing in the subsequent transitions.
4.0
Processor Feature
4.1
Functional Redundancy Checking Mode
Two Pentium III Xeon processor agents may be configured as an FRC (functional redundanc
checking) pair. In this configuration, one processor acts as the master and the other acts as a
checker, and the pair operates as a single processor. If the checker agent detects a mismatch
between its internally sampled outputs and the master processor’s outputs, the checker asserts
FRCERR. FRCERR observation can be enabled at the master processor with software. The master
enters machine check on an FRCERR provided that Machine Check Execution is enabled.
For proper synchronization of signals when operating in FRC mode, see Section 9.1.23. ITP
operation is not supported in FRC mode.
Systems configured to implement FRC mode must write all of the processors’ internal MSRs to
deterministic values before performing either a read or read-modify-write operation using these
registers. The following is a list of MSRs that are not initialized by the processors’ reset sequences.
1. All fixed and variable MTRRs,
2. All Machine Check Architecture (MCA) status registers,
3. Microcode Update signature register, and
4. All L2 Cache initialization MSRs.
36
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
4.2
Low Power States and Clock Control
The Pentium III Xeon processor allows the use of Auto HALT, Stop-Grant, and Sleep states to
reduce power consumption by stopping the clock to specific internal sections of the processor,
depending on each particular state. There is no Deep Sleep state on the Pentium III Xeon processor.
Refer to for the following sections on low power states for the Pentium III Xeon processor.
For the processor to fully realize the low current consumption of the Stop Grant, and Sleep states,
an MSR bit must be set. For the MSR at 02AH (Hex), bit 26 must be set to a ‘1’ (power on default
is a ‘0’) for the processor to stop all internal clocks during these modes. For more information, see
the Intel Architecture Software Developer’s Manual, Volume III: System Programming Guide.
Due to not being able to recognize bus transactions during Sleep state, SMP systems are not
allowed to have one or more processors in Sleep state and other processors in Normal or Stop Grant
states simultaneously.
4.2.1
Normal State— State 1
This is the normal operating state for the processor
4.2.2
Auto Halt Power Down State — State 2
Auto HALT is a low power state entered when the Pentium III Xeon processor executes the HALT
instruction. The processor will issue a normal HALT bus cycle on BE[7:0]# and REQ[4:0]# when
entering this state. The processor will transition to the Normal state upon the occurrence of SMI#,
BINIT#, INIT#, or LINT[1:0] (NMI, INTR). RESET# will cause the processor to immediately
initialize itself.
SMI# will cause the processor to execute the SMI handler. The return from the SMI handler can be
to either Normal Mode or the Auto HALT Power Down state. See Chapter 11 in the Intel
Architecture Software Developer’s Manual, Volume III: System Programming Guide.
FLUSH# will be serviced during Auto HALT state. The on-chip first level caches and external
second level cache will be flushed and the processor will return to the Auto HALT state.
A20M# will be serviced during Auto HALT state; the processor will mask physical address bit 20
(A20#) before any look-up in either the on-chip first level caches or external second level cache,
and before a read/write transaction is driven on the bus.
The system can generate a STPCLK# while the processor is in the Auto HALT Power Down state.
The processor will generate a Stop Grant bus cycle when it enters the Stop Grant state from the
HALT state. If the processor enters the Stop Grant state from the Auto HALT state, the STPCLK#
signal must be deasserted before any interrupts are serviced (see below). When the system
deasserts the STPCLK# interrupt signal, the processor will return execution to the HALT state. The
processor will not generate a new HALT bus cycle when it re-enters the HALT state from the Stop
Grant state.
Datasheet
37
Pentium® III Xeon™ Processor at 500 and 550 MHz
Figure 16. Stop Clock State Machine
HALT Instruction and
HALT Bus Cycle Generated
2. Auto HALT Power Down State
BCLK running.
Snoops and interrupts allowed.
INIT#, BINIT#, INTR, NMI,
SMI#, RESET#
STPC
LK#
Snoop
Event
Occurs
Snoop
Event
Serviced
STPC
LK#
4. HALT/Grant Snoop State
BCLK running.
Service snoops to caches.
De-a
ssert
ed
Snoop Event Occurs
Snoop Event Serviced
A sse
rted
1. Normal State
Normal execution.
STPCLK#
Asserted
STPCLK#
De-asserted
3. Stop Grant State
BCLK running.
Snoops and interrupts allowed.
SLP#
Asserted
SLP#
De-asserted
5. Sleep State
BCLK running.
No snoops or interrupts allowed.
4.2.3
Stop-Grant State — State 3
The Stop-Grant state on the Pentium III Xeon processor is entered when the STPCLK# signal is
asserted. The Pentium III Xeon processor will issue a Stop-Grant Transaction Cycle. Exit latency
from this mode is 10 BLCK periods after the STPCLK# signal is deasserted.
Since the AGTL+ signal pins receive power from the system bus, these pins should not be driven
(allowing the level to return to VTT) for minimum power drawn by the termination resistors in this
state. In addition, all other input pins on the system bus should be driven to the inactive state.
BINIT# will not be serviced while the processor is in Stop-Grant state. The event will be latched
and can be serviced by software upon exit from Stop-Grant state.
FLUSH# will not be serviced during Stop Grant state.
RESET# will cause the processor to immediately initialize itself; but the processor will stay in Stop
Grant state. A transition back to the Normal state will occur with the deassertion of the STPCLK#
signal.
A transition to the HALT/Grant Snoop state will occur when the processor detects a snoop phase on
the system bus. A transition to the Sleep state will occur with the assertion of the SLP# signal.
While in the Stop Grant State, all other interrupts will be latched by the Pentium III Xeon processor,
and only serviced when the processor returns to the Normal State.
38
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
4.2.4
Halt/Grant Snoop State — State 4
The Pentium III Xeon processor will respond to snoop phase transactions (initiated by ADS#) on
the system bus while in Stop-Grant state or in Auto HALT Power Down state. When a snoop
transaction is presented upon the system bus, the processor will enter the HALT/Grant Snoop state.
The processor will stay in this state until the snoop on the system bus has been serviced (whether
by the processor or another agent on the system bus). After the snoop is serviced, the processor will
return to the Stop-Grant state or Auto HALT Power Down state, as appropriate.
4.2.5
Sleep State — State 5
The Sleep state is a very low power state in which the processor maintains its context, maintains the
PLL, and has stopped all internal clocks. The Sleep state can only be entered from Stop-Grant state.
Once in the Stop-Grant state (verified by the termination of the Stop-Grant Bus transaction cycle),
the SLP# pin can be asserted, causing the Pentium III Xeon processor to enter the Sleep state. The
system must wait 100 BCLK cycles after the completion of the Stop-Grant Bus cycle before SLP#
is asserted. For an MP system, all processors must complete the Stop Grant bus cycle before the
subsequent 100 BCLK wait and assertion of SLP# can occur. The processor is in Sleep state 10
BCLKs after the assertion of the SLP# pin. The latency to exit the Sleep state is 10 BCLK cycles.
The SLP# pin is not recognized in the Normal, or Auto HALT States.
Snoop events that occur during a transition into or out of Sleep state will cause unpredictable
behavior. Therefore, transactions should be blocked by system logic during these transitions.
In the Sleep state, the processor is incapable of responding to snoop transactions or latching
interrupt signals immediately after the assertion of the SLP# pin (one exception is RESET# which
causes the processor to re-initialize itself). The system core logic must detect these events and
deassert the SLP# signal (and subsequently deassert the STPCLK# signal for interrupts) for the
processor to correctly interpret any bus transaction or signal transition. Once in the Sleep state, the
SLP# pin can be deasserted if another asynchronous event occurs.
No transitions or assertions of signals are allowed on the system bus while the Pentium III Xeon
processor is in Sleep state. Any transition on an input signal (with the exception of SLP# or
RESET#) before the processor has returned to Stop Grant state will result in unpredictable
behavior.
If RESET# is driven active while the processor is in the Sleep state, and held active as specified in
the RESET# pin specification, then the processor will reset itself, ignoring the transition through
Stop Grant State. If RESET# is driven active while the processor is in the Sleep State and normal
operation is desired, the SLP# and STPCLK# should be deasserted immediately after RESET# is
asserted.
4.2.6
Clock Control
The Pentium III Xeon processor provides the clock signal to the L2 Cache. The processor does not
stop this clock to the second level cache during Auto HALT Power Down or Stop-Grant states.
During Auto HALT Power Down and Stop-Grant states, the processor will continue to process the
snoop phase of a system bus cycle. The PICCLK signal should not be removed during the Auto
HALT Power Down or Stop-Grant states.
When the processor is in the Sleep state, it will not respond to interrupts or snoop transactions.
PICCLK can be removed during the Sleep state.
Datasheet
39
Pentium® III Xeon™ Processor at 500 and 550 MHz
The processor will not enter any low power states until all internal queues for the second level
cache are empty. When re-entering Normal state, the processor will resume processing external
cache requests as soon as new requests are encountered.
4.3
System Management Bus (SMBus) Interface
The Pentium III Xeon processor includes an SMBus interface which allows access to several
processor features, including two memory components (referred to as the Processor Information
ROM and the Scratch EEPROM) and a thermal sensor on the Pentium III Xeon processor substrate.
These devices and their features are described below.
The Pentium III Xeon processor SMBus implementation uses the clock and data signals of the
SMBus specification. It does not implement the SMBSUS# signals.
Figure 17. Logical Schematic of SMBus Circuitry
VCC_SMB
10K
10K
Core
TDIODEA
TDIODEC
Vcc
A0
A1
Processor
Information
ROM
A2
SC
SD
Vcc
STBY#
A0
10K
Thermal
Sensing
Device
Vcc
ALERT#
A1
A0
SC
SD
10K
A1
10K
A2
Scratch
EEPROM
SA2
A159
SA1
A162
SA0
A163
NOTE:
40
SC
SD
WP
WP
B148
SMBDATA
B161
SMBCLK
B160
SMBALERT#
A151
Actual implementation may vary. For use in general understanding of the architecture.
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
4.3.1
Processor Information ROM
An electrically programmed read-only memory with information about the Pentium III Xeon
processor is provided on the processor substrate. This information is permanently write-protected.
Table 23 shows the data fields and formats provided in the memory.
Table 23. Processor Information ROM Format (Sheet 1 of 2)
Offset/Section
Function
Notes
HEADER: 00h
8
Data Format Revision
Two 4-bit hex digits
01h
16
EEPROM Size
Size in bytes (MSB first)
03h
8
Processor Data Address
Byte pointer, 00h if not present
04h
8
Processor Core Data Address
Byte pointer, 00h if not present
05h
8
L2 Cache Data Address
Byte pointer, 00h if not present
06h
8
SEC Cartridge Data Address
Byte pointer, 00h if not present
07h
8
Part Number Data Address
Byte pointer, 00h if not present
08h
8
Thermal Reference Data
Addres
Byte pointer, 00h if not present
09h
8
Feature Data Address
Byte pointer, 00h if not present
0Ah
8
Other Data Address
Byte pointer, 00h if not present
0Bh
16
Reserved
Reserved for future use
0Dh
8
Checksum
1 byte checksum
PROCESSOR: 0Eh
48
S-spec/QDF Number
Six 8-bit ASCII characters
2
Sample/Production
00b = Sample only
6
Reserved
Reserved for future use
8
Checksum
1 byte checksum
2
Processor Core Type
From CPUID
4
Processor Core Family
From CPUID
4
Processor Core Model
From CPUID
4
Processor Core Steppin
From CPUID
42
Reserved
Reserved for future use
16
Maximum Core Frequency
16-bit binary number (in MHz)
16
Core Voltage ID
Voltage in mV
8
Core Voltage Tolerance, Hig
Edge finger tolerancein mV, +
8
Core Voltage Tolerance, Low
Edge finger tolerancein mV,
8
Reserved
Reserved for future use
CORE: 16h
L2 CACHE: 25h
Datasheet
# of Bits
8
Checksum
1 byte checksum
32
Reserved
Reserved for future use
16
L2 Cache Size
16-bit binary number (in Kbytes
4
Number of SRAM Components
One 4-bit hex digit
4
Reserved
Reserved for future use
16
L2 Cache Voltage ID
Voltage in mV
41
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 23. Processor Information ROM Format (Sheet 2 of 2)
Offset/Section
CARTRIDGE: 32h
PART NUMBERS:
38h
THERMAL REF.:
70h
FEATURES: 74h
OTHER: 7Eh
4.3.2
# of Bit
Function
Notes
8
L2 Cache Voltage Tolerance,
High
Edge finger tolerancein mV, +
8
L2 Cache Voltage Tolerance, Low
Edge finger tolerancein mV, -
4
Cache/Tag Stepping ID
One 4-bit hex digit
4
Reserved
Reserved for future use
8
Checksu
1 byte checksu
32
Cartridge Revision
Four 8-bit ASCII characters
2
Substrate Rev. Software ID
2-bit revision number
6
Reserved
Reserved for future use
8
Checksu
1 byte checksu
56
Processor Part Number
Seven 8-bit ASCII characters
112
Processor BOM ID
Fourteen 8-bit ASCII characters
64
Processor Electronic Signature
64-bit processor number
208
Reserved
Reserved for future use
8
Checksu
1 byte checksu
8
Thermal Reference Byte
See below
16
Reserved
Reserved for future use
8
Checksu
1 byte checksu
32
Processor Core Feature Flags
From CPUID
32
Cartridge Feature Flags
[6]
[5]
[4]
[3]
[2]
[1]
[0]
4
Number of Devices inTAP Chain
One 4-bit hex digit
4
Reserved
Reserved for future use
8
Checksu
1 byte checksu
16
Reserved
Reserved for future use
= Serial Signature
= Electronic Signature Present
= Thermal Sense Device Present
= Thermal Reference Byte Present
= OEM EEPROM Present
= Core VID Present
= L2 Cache VID Present
Scratch EEPROM
Also available on the SMBus is an EEPROM which may be used for other data at the system or
processor vendor’s discretion. The data in this EEPROM, once programmed, can be writeprotected by asserting the active-high WP signal. This signal has a weak pull-down (10 kΩ) to
allow the EEPROM to be programmed in systems with no implementation of this signal. The
Scratch EEPROM is a 1024 bit part.
42
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
4.3.3
Processor Information ROM and Scratch EEPROM Supported SMBus
Transactions
The Processor Information ROM responds to three SMBus packet types: current address read,
random address read, and sequential read. The Scratch EEPROM responds to two additional packet
types: byte write and page write. Table 24 diagrams the current address read. The internal address
counter keeps track of the address accessed during the last read or write operation, incremented by
one. Address “roll over” during reads is from the last byte of the last eight byte page to the first byte
of the first page. “Roll over” during writes is from the last byte of the current eight byte page to the
first byte of the same page. Table 25 diagrams the random read. The write with no data loads the
address desired to be read.
Sequential reads may begin with a current address read or a random address read. After the SMBus
host controller receives the data word it responds with an acknowledge. This will continue until the
SMBus host controller responds with a negative acknowledge and a stop. Table 26 diagrams the
byte write. The page write operates the same way as the byte write except that the SMBus host
controller does not send a stop after the first data byte and acknowledge. The Scratch EEPROM
internally increments its address. The SMBus host controller continues to transmit data bytes until
it terminates the sequence with a stop. All data bytes will result in an acknowledge from the
Scratch EEPROM. If more than eight bytes are written the internal address will “roll over” and the
previous data will be overwritten. In the tables, ‘S’ represents the SMBus start bit, ‘P’ represents a
stop bit, ‘R’ represents a read bit, ‘W’ represents a write bit, ‘A’ represents an acknowledge, and ‘//
/’ represents a negative acknowledge. The shaded bits are transmitted by the Processor Information
ROM or Scratch EEPROM, and the bits that aren’t shaded are transmitted by the SMBus host
controller. In the tables the data addresses indicate 8 bits. The SMBus host controller should
transmit 8 bits, but as there are only 128 addresses, the most significant bit is a don’t care.
Table 24. Current Address Read SMBus Packet
S
Device Address
R
A
Data
///
P
1
7 bits
1
1
8 bits
1
1
Table 25. Random Address Read SMBus Packet
S
Device
Address
W
A
Data
Address
A
S
Device
Address
R
A
Data
///
P
1
7 bits
1
1
8 bits
1
1
7 bits
1
1
8 bits
1
1
Table 26. Byte Write SMBus Packet
S
Device Addres
W
A
Data Addres
A
Data
A
P
1
7 bits
1
1
8 bits
1
8 bits
1
1
4.3.4
Thermal Sensor
The Pentium III Xeon processor’s thermal sensor provides a means of acquiring thermal data from
the processor with an exceptional degree of precision. The thermal sensor is composed of control
logic, SMBus interface logic, a precision analog-to-digital converter, and a precision current
source. The thermal sensor drives a small current through the p-n junction of a thermal diode
located on the same silicon die as the processor core. The forward bias voltage generated across the
Datasheet
43
Pentium® III Xeon™ Processor at 500 and 550 MHz
thermal diode is sensed and the precision A/D converter derives a single byte of thermal reference
data, or a “thermal byte reading.” System management software running on the processor or on a
microcontroller can acquire the data from the thermal sensor to thermally manage the system.
Upper and lower thermal reference thresholds can be individually programmed for the thermal
diode. Comparator circuits sample the register where the single byte of thermal data (thermal byte
reading) is stored. These circuits compare the single byte result against programmable threshold
bytes. The alert signal on the Pentium III Xeon processor SMBus (SMBALERT#) will assert when
either threshold is crossed.
To increase the usefulness of the thermal diode and thermal sensor, Intel has added a new
procedure to the manufacturing and test flow of the Pentium III Xeon processor. This procedure
determines the Thermal Reference Byte and programs it into the Processor Information ROM. The
Thermal Reference Byte is uniquely determined for each unit. The procedure causes each unit to
dissipate its maximum power (which can vary from unit to unit) while at the same time maintaining
the thermal plate at its maximum specified operating temperature. Correctly used, this feature
permits an efficient thermal solution while preserving data integrity.
The thermal byte reading can be used in conjunction with the Thermal Reference Byte in the
Processor Information ROM. Byte 9 of the Processor Information ROM contains the address in the
ROM of this byte, described in more detail in Section 4.3.1. The thermal byte reading from the
thermal sensor can be compared to this Thermal Reference Byte to provide an indication of the
difference between the temperature of the processor core at the instant of the thermal byte reading
and the temperature of the processor core under the steady state conditions of high power and
maximum TPLATE specifications. The nominal precision of the least significant bit of a thermal
byte is 1°C.
Reading the thermal sensor is explained in Section 4.3.5. See the Pentium® III Xeon™ Processor
SMBus Thermal Reference Guidelines for more details and further recommendations on the use of
this feature in Pentium III Xeon processor-based systems.
The thermal sensor feature in the processor cannot be used to measure TPLATE. The TPLATE
specification in Section 5.0 must be met regardless of the reading of the processor's thermal sensor
in order to ensure adequate cooling for the entire Pentium III Xeon processor. The thermal sensor
feature is only available while VCCCORE and VCCSMBUS are at valid levels and the processor is not
in a low-power state.
4.3.5
Thermal Sensor Supported SMBus Transactions
The thermal sensor responds to five of the SMBus packet types: write byte, read byte, send byte,
receive byte, and Alert Response Address (ARA). The send byte packet is used for sending oneshot commands only. The receive byte packet accesses the register commanded by the last read
byte packet. If a receive byte packet was preceded by a write byte or send byte packet more recently
than a read byte packet, then the behavior is undefined. Table 27 through Table 31 diagram the five
packet types. In these figures, ‘S’ represents the SMBus start bit, ‘P’ represents a stop bit, ‘Ack’
represents an acknowledge, and ‘///’ represents a negative acknowledge. The shaded bits are
transmitted by the thermal sensor, and the bits that aren’t shaded are transmitted by the SMBus host
controller. Table 32 shows the encoding of the command byte.
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Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 27. Write Byte SMBus Packet
S
Address
Write
Ack
Command
Ack
Data
Ack
P
1
7 bits
1
1
8 bits
1
8 bits
1
1
Table 28. Read Byte SMBus Packet
S
Addres
Write
Ack
Command
Ack
S
Addres
Read
Ack
Data
///
P
1
7 bits
1
1
8 bits
1
1
7 bits
1
1
8 bits
1
1
Table 29. Send Byte SMBus Packet
S
Addres
Write
Ack
Command
Ack
P
1
7 bits
1
1
8 bits
1
1
Table 30. Receive Byte SMBus Packet
S
Address
Read
Ack
Data
///
P
1
7 bits
1
1
8 bits
1
1
Table 31. ARA SMBus Packet
S
ARA
Read
Ack
Address
///
P
1
0001 100
1
1
Device Address†
1
1
† This is an 8-bit field. The device which sent the alert will respond to the ARA Packet with its address in the
seven most significant bits. The least significant bit is undefined and may return as a ‘1’ or ‘0’. See Section
4.3.7 for details on the Thermal Sensor Device addressing.
Table 32. Command Byte Bit Assignments (Sheet 1 of 2)
Register
RESERVED
Datasheet
Command
00h
Reset State
N/A
Function
Reserved for future use
RRT
01h
N/A
Read processor core thermal data
RS
02h
N/A
Read status byte (flags, busy signal)
RC
03h
0000 0000
Read configuration byte
RCR
04h
0000 0010
Read conversion rate byte
RESERVED
05h
0111 1111
Reserved for future use
RESERVED
06h
1100 1001
Reserved for future use
RRHL
07h
0111 1111
Read processor core thermal diode T HIGH limit
RRLL
08h
1100 1001
Read processor core thermal diode T LOW limit
WC
09h
N/A
Write configuration byte
WCR
0Ah
N/A
Write conversion rate byte
RESERVED
0Bh
N/A
Reserved for future use
45
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 32. Command Byte Bit Assignments (Sheet 2 of 2)
Register
Command
Reset State
Function
RESERVED
0Ch
N/A
Reserved for future use
WRHL
0Dh
N/A
Write processor core thermal diode THIGH limit
WRLL
0Eh
N/A
Write processor core thermal diode TLOW lim
OSHT
0Fh
N/A
One shot command (use send byte packet)
RESERVED
10h – FFh
N/A
Reserved for future use
All of the commands are for reading or writing registers in the thermal sensor except the one-shot
command (OSHT). The one-shot command forces the immediate start of a new conversion cycle. If
a conversion is in progress when the one-shot command is received, then the command is ignored.
If the thermal sensor is in standby mode when the one-shot command is received, a conversion is
performed and the sensor returns to standby mode. The one-shot command is not supported when
the thermal sensor is in auto-convert mode.
The default command after reset is to a reserved value (00h). After reset, receive byte packets will
return invalid data until another command is sent to the thermal sensor.
4.3.6
Thermal Sensor Register
4.3.6.1
Thermal Reference Registers
The processor core and thermal sensor internal thermal reference registers contain the thermal
reference value of the thermal sensor and the processor core thermal diodes. This value ranges from
+127 to -128 decimal and is expressed as a two’s complement, eight-bit number. These registers are
saturating, i.e., values above 127 are represented at 127 decimal, and values below -128 are
represented as -128 decimal.
4.3.6.2
Thermal Limit Registers
The thermal sensor has two thermal limit registers; they define high and low limits for the
processor core thermal diode. The encoding for these registers is the same as for the thermal
reference registers. If the diode thermal value equals or exceeds one of its limits, then its alarm bit
in the Status Register is triggered.
4.3.6.3
Status Register
The status register shown in Table 33 indicates which (if any) thermal value thresholds have been
exceeded. It also indicates if a conversion is in progress or if an open circuit has been detected in
the processor core thermal diode connection. Once set, alarm bits stay set until they are cleared by
a status register read. A successful read to the status register will clear any alarm bits that may have
been set, unless the alarm condition persists.
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Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 33. Thermal Sensor Status Register
4.3.6.4
Bit
Name
Function
7 (MSB)
BUSY
A one indicates that the device’s analog to digital converter is busy converting.
6
RESERVED
Reserved for future use
5
RESERVED
Reserved for future use
4
RHIGH
A one indicates that the processor core thermal diode high temperature alarm
has activated.
3
RLOW
A one indicates that the processor core thermal diode low temperature alarm
has activated.
2
OPE
A one indicates an open fault in the connection to the processor core diode.
1
RESERVED
Reserved for future use.
0 (LSB)
RESERVED
Reserved for future use.
Configuration Register
The configuration register controls the operating mode (standby vs. auto-convert) of the thermal
sensor. Table 34 shows the format of the configuration register. If the RUN/STOP bit is set (high)
then the thermal sensor immediately stops converting and enters standby mode. The thermal sensor
will still perform analog to digital conversions in standby mode when it receives a one-shot
command. If the RUN/STOP bit is clear (low) then the thermal sensor enters auto-conversion
mode.
Table 34. Thermal Sensor Configuration Register
Bit
7 (MSB)
4.3.6.5
Name
RESERVED
Reset State
Function
0
Reserved for future use.
6
RUN/STOP
0
Standby mode control bit. If high, the device immediately stops
converting, and enters standby mode. If low, the device converts in
either one-shot mode or automatically updates on a timed basis.
5-0
RESERVED
0
Reserved for future use.
Conversion Rate Register
The contents of the conversion rate register determine the nominal rate at which analog to digital
conversions happen when the thermal sensor is in auto-convert mode. Table 35 shows the mapping
between conversion rate register values and the conversion rate. As indicated in Table 32, the
conversion rate register is set to its default state of 02h (0.2 5Hz nominally) when the thermal
sensor is powered up. There is a ±25% error tolerance between the conversion rate indicated in the
conversion rate register and the actual conversion rate.
Datasheet
47
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 35. Thermal Sensor Conversion Rate Register
4.3.7
Register Contents
Conversion Rate (Hz)
00h
0.0625
01h
0.125
02h
0.25
03h
0.5
04h
1
05h
2
06h
4
07h
8
08h to FF
Reserved for future use
SMBus Device Addressing
Of the addresses broadcast across the SMBus, the memory components claim those of the form
“1010XXYZb”. The “XX” and “Y” bits are used to enable the devices on the cartridge at adjacent
addresses. The Y bit is hard-wired on the cartridge to VSS (‘0’) for the Scratch EEPROM and
pulled to VCCSMBUS (‘1’) for the Processor Information ROM. The “XX” bits are defined by the
processor slot via the SA0 and SA1 pins on the SC330 connector. These address pins are pulled
down weakly (10 kΩ) to ensure that the memory components are in a known state in systems which
do not support the SMBus, or only support a partial implementation. The “Z” bit is the read/write
bit for the serial bus transaction.
The thermal sensor internally decodes 1 of 3 upper address patterns from the bus of the form
“0011XXXZb”, “1001XXXZb” or “0101XXXZb”. The device’s addressing, as implemented, uses
SA2 and SA1 and includes a Hi-Z state for the SA2 address pin. Therefore the thermal sensor
supports 6 unique resulting addresses. To set the Hi-Z state for SA2, the pin must be left floating.
The system should drive SA1 and SA0, and will be pulled low (if not driven) by the 10k Ω pulldown resistor on the processor substrate. Attempting to drive either of these signals to a Hi-Z state
would cause ambiguity in the memory device address decode, possibly resulting in the devices not
responding, thus timing out or hanging the SMBus. As before, the “Z” bit is the read/write bit for
the serial bus transaction.
Note:
Addresses of the form “0000XXXXb” are Reserved and should not be generated by an SMBus
master.
The thermal sensor latches the SA1 and SA2 signals at power up. System designers should ensure
that these signals are at valid input levels (see Table 9) before the thermal sensor powers up. This
should be done by pulling the pins to VCCSMBUS or VSS via a 1 kΩ or smaller resistor. Additionally,
SA2 may be left unconnected to achieve the tri-state or “Z” state. If the designer desires to drive the
SA1 or SA2 pin with logic the designer must ensure that the pins are at valid input levels (see Table
9) before VCCSMBUS begins to ramp. The system designer must also ensure that their particular
system implementation does not add excessive capacitance (>50 pF) to the address inputs. Excess
capacitance at the address inputs may cause address recognition problems.
Figure 17 shows a logical diagram of the pin connections. Table 36 and Table 37 describe the
address pin connections and how they affect the addressing of the devices.
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Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 36. Thermal Sensor SMBus Addressing on the Pentium ® III Xeon™ Processor
Address (Hex)
Upper Address1
3Xh
5Xh
Slot Selec
SA1
SA2
b[7:0]
0011
0
0
0011000Xb
0011
1
0
0011010Xb
0101
9Xh
8-bit Address Word on Serial Bus
0
2
0101001Xb
2
Z
0101
1
Z
0101011Xb
1001
0
1
1001100Xb
1001
1
1
1001110Xb
NOTES
1. Upper address bits are decoded in conjunction with the select pins.
2. A tri-state or “Z” state on this pin is achieved by leaving this pin unconnected.
Note:
System management software must be aware of the slot number-dependent changes in the address
for the thermal sensor.
Table 37. Memory Device SMBus Addressing on the Pentium® III Xeon™ Processor
Address
(Hex)
Upper
Address
Slot Select
Memory
Device Selec
R/W
Device Addressed
bits 7-4
(SA1)
bit 3
(SA0)
bit 2
bit 1
bit 0
A0h/A1h
1010
0
0
0
X
Scratch EEPROM 1
A2h/A3h
1010
0
0
1
X
Processor Information ROM 1
A4h/A5h
1010
0
1
0
X
Scratch EEPROM 2
A6h/A7h
1010
0
1
1
X
Processor Information ROM 2
A8h/A9h
1010
1
0
0
X
Scratch EEPROM 3
Aah/Abh
1010
1
0
1
X
Processor Information ROM 3
Ach/Adh
1010
1
1
0
X
Scratch EEPROM 4
Aeh/Afh
1010
1
1
1
X
Processor Information ROM 4
Though this addressing scheme is targeted for up to 4-way MP systems, more processors can be
supported by using a multiplexed (or separate) SMBus implementation.
5.0
Thermal Specifications and Design Consideration
The Pentium III Xeon processor will use a thermal plate for heatsink attachment. The thermal plate
interface is intended to provide for multiple types of thermal solutions. This chapter will provide
the necessary data for a thermal solution to be developed. See Figure 18 for thermal plate location.
Datasheet
49
Pentium® III Xeon™ Processor at 500 and 550 MHz
Figure 18. Thermal Plate View
5.1
Thermal Specifications
This section provides power dissipation specifications for each variation of the Pentium III Xeon
processor. The thermal plate flatness is also specified for the S.E.C. cartridge.
5.1.1
Power Dissipation
Table 38 provides the thermal design power dissipation for Pentium III Xeon processors. While the
processor core dissipates the majority of the thermal power, the system designer should also be
aware of the thermal power dissipated by the second level cache. Systems should design for the
highest possible thermal power, even if a processor with lower frequency or smaller second level
cache is planned. The thermal plate is the attach location for all thermal solutions. The maximum
temperature for the entire thermal plate surface is shown in Table 38.
The processor power is dissipated through the thermal plate and other paths. The power dissipation
is a combination of power from the processor core, the second level cache and the AGTL+ bus
termination resistors. The overall system thermal design must comprehend the total processor
power. The combined power from the processor core and the second level cache that dissipates
through the thermal plate is the thermal plate power. The heatsink should be designed to dissipate
the thermal plate power.
The thermal sensor feature of the processor cannot be used to measure TPLATE. The TPLATE
specification must be met regardless of the reading of the processor's thermal sensor in order to
ensure adequate cooling for the entire Pentium III Xeon processor.
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Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 38. Thermal Design Power
1
Processor
Core
Frequency
(MHz)
L2
Cache
Size
Core
Power
(W)
L2
Power
(W)
AGTL+
Power4
(W)
Processor
Power2
(W)
Thermal
Plate
Power3
(W)
Min
TPLATE
(°C)
Max
TPLATE
(°C)
Min
TCOVER
(°C)
Max
TCOVER
(°C)
FMB5
-
35.2
21.0
2
50.0
50.0
0
68
0
75
500
512K
28.0
12.0
2
36.0
37.0
0
75
0
75
500
1M
28.0
19.0
2
44.0
45.0
0
75
0
75
500
2M
28.0
11.6
2
36.2
37.1
0
75
0
75
550
512K
30.8
7.0
2
34.0
35.0
0
68
0
75
550
1M
30.8
7.0
2
34.0
35.0
0
68
0
75
550
2M
30.8
12.4
2
39.5
40.5
0
68
0
75
NOTES
1. These values are specified at nominal V CCCORE for the processor core and nominal V CCL2 for the L2 cache.
2. Processor power indicates the worst case power that can be dissipated by the entire processor. This value
will be determined after the product has been characterized. It is not possible for the AGTL+ bus, the L2
cache and the processor core to all be at full power simultaneously.
3. The combined power that dissipates through the thermal plate is the thermal plate power. This value will be
determined after the product has been characterized. The value shown follows the expectation that virtually
all of the power will dissipate through the thermal plate.
4. AGTL+ power is the worst case power dissipated in the termination resistors for the AGTL+ bus.
5. “FMB” is a suggested design guideline for a flexible baseboard design. Notice that worst case L2 power and
worst case processor power do not occur on the same processor.
5.1.2
Plate Flatness Specification
The thermal plate flatness for the Pentium III Xeon processor is specified to 0.010" across the entire
thermal plate surface, with no more than a 0.003" step anywhere on the surface of the plate, as
shown in Figure 19.
Figure 19. Plate Flatness Reference
.003/1.00x1.00
Datasheet
51
Pentium® III Xeon™ Processor at 500 and 550 MHz
5.2
Processor Thermal Analysis
5.2.1
Thermal Solution Performance
Processor cooling solutions should attach to the thermal plate. The processor cover is not designed
for thermal solution attachment.
The complete thermal solution must adequately control the thermal plate and cover temperatures
below the maximum and above the minimum specified in Table 38. The performance of any
thermal solution is defined as the thermal resistance between the thermal plate and the ambient air
around the processor (Θthermal plate to ambient). The lower the thermal resistance between the thermal
plate and the ambient air, the more efficient the thermal solution is. The required
Θthermal plate to ambient is dependent upon the maximum allowed thermal plate temperature
(TPLATE), the local ambient temperature (TLA) and the thermal plate power (PPLATE).
Θthermal plate to ambient = (TPLATE – TLA)/PPLATE
The maximum TPLATE and the thermal plate power are listed in Table 38. TLA is a function of the
system design. Table 39 provides the resultant thermal solution performance for a Pentium III Xeon
processor at maximum power dissipation allowable under FMB constraints for different ambient
air temperatures around the processor
Table 39. Example Thermal Solution Performance at Thermal Plate Power of 50 Watts
Thermal Solution Performance
Local Ambient Temperature (T LA)
Θthermal plate to ambient
35 °C
40 °C
45 °C
(°C/watt)
0.8
0.7
0.6
The Θthermal plate to ambient value is made up of two primary components: the thermal resistance
between the thermal plate and heatsink (Θthermal plate to heatsink) and the thermal resistance between
the heatsink and ambient air around the processor (Θheatsink to air). A critical, but controllable factor
to decrease the resultant value of Θthermal plate to heatsink is management of the thermal interface
between the thermal plate and heatsink. The other controllable factor (Θheatsink to air) is determined
by the design of the heatsink and airflow around the heatsink. General Information on thermal
interfaces and heatsink design constraints can be found in AP-586, Pentium® II Processor Thermal
Design Guidelines.
5.2.2
Thermal Plate to Heat Sink Interface Management Guide
Figure 20 shows suggested interface agent dispensing areas when using an Intel suggested interface
agent. Actual user area and interface agent selections will be determined by system issues in
meeting the TPLATE requirements.
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Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Figure 20. Interface Agent Dispensing Areas and Thermal Plate Temperature Measurement
Points
1.960
.980
NOTES
6. Interface agent suggestions: ShinEtsu* G749 or Thermoset* TC330; Dispense volume adequate to ensure
required minimum area of coverage when cooling solution is attached. Areas A and C are suggested for the
512-Kbyte L2 cache product and areas A, B, and D for the 1-Mbyte and 2-Mbyte L2 cache products.
Recommended cooling solution mating surface flatness is no greater than 0.007" or flatter.
7. Temperature of the entire thermal plate surface not to exceed specification. Use any combination of interface
agent, cooling solution, flatness condition, etc., to ensure this condition is met. Thermocouple measurement
locations are the expected high temperature locations without external heat source influence. Ensure that
external heat sources do not cause a violation of T PLATE requirements
5.2.3
Measurements for Thermal Specifications
5.2.3.1
Thermal Plate Temperature Measurement
To ensure functional and reliable processor operation, the processor’s thermal plate temperature
(TPLATE) must be maintained at or below the maximum TPLATE and at or above the minimum
TPLATE specified in Table 38. Power from the processor core and L2 cache is transferred to the
thermal plate at 2 locations on the 512-Kbyte L2 cache product and 3 locations on the 1-Mbyte and
Datasheet
53
Pentium® III Xeon™ Processor at 500 and 550 MHz
2-Mbyte L2 cache products. Figure 20 shows the locations for TPLATE measurement directly above
these transfer locations. Figure 23 shows the 4 locations for TCOVER measurement, directly above
component locations on the back side of the processor substrate.
Thermocouples are used to measure TPLATE and special care is required to ensure an accurate
temperature measurement. Before taking any temperature measurements, the thermocouples must
be calibrated. When measuring the temperature of a surface, errors can be introduced in the
measurement if not handled properly. Such measurement errors can be due to a poor thermal
contact between the thermocouple junction and the measured surface, conduction through
thermocouple leads, heat loss by radiation and convection, or by contact between the thermocouple
cement and the heatsink base. To minimize these errors, the following approach is recommended:
• Use 36 gauge or finer diameter K, T, or J type thermocouples. Intel's laboratory testing was
done using a thermocouple made by Omega* (part number: 5TC-TTK-36-36).
• Attach each thermocouple bead or junction to the top surface of the thermal plate at the
locations specified in Figure 20 using high thermal conductivity cements.
• A thermocouple should be attached at a 0° angle if no heatsink is attached to the thermal plate.
If a heatsink is attached to the thermal plate but the heatsink does not cover the location
specified for TPLATE measurement, the thermocouple should be attached at a 0° angle (refer to
Figure 21).
• The thermocouple should be attached at a 90° angle if a heatsink is attached to the thermal
plate and the heatsink covers the location specified for T PLATE measurement (refer to Figure
22).
• The hole size through the heatsink base to route the thermocouple wires out should be smaller
than 0.150" in diameter
• Make sure there is no contact between the thermocouple cement and heatsink base. This
contact will affect the thermocouple reading.
Figure 21. Technique for Measuring TPLATE with 0° Angle Attachment
Figure 22. Technique for Measuring TPLATE with 90° Angle Attachment
5.2.3.2
Cover Temperature Measurement Guideline
The maximum and minimum S.E.C. cartridge cover temperature (TCOVER) for Pentium III Xeon
processors are specified in Table 38. Meeting this temperature specification is required to ensure
correct and reliable operation of the processor. In the design of a system, other sources of heat
convection, conduction or radiation should be evaluated for any possible effect on the cartridge
cover temperature. In a system free from such external sources of heat, the higher temperature
54
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
areas on the cover have been characterized and are illustrated in Figure 23. If no external heat
sources are present, TCOVER thermal measurements should be made at these points. The cover is
not designed for thermal solution attachment.
Figure 23. Guideline Locations for Cover Temperature (TCOVER) Thermocouple Placement
NOTE:
8. Four thermocouple attach locations at ±0.015". Thermocouple measurement locations are the expected high
temperature locations, without external heat source influence. Temperature of entire cover surface not to
exceed 7 °C. Ensure that external heat sources do not cause a violation of T COVER requirements.
6.0
Mechanical Specification
Pentium III Xeon processors use S.E.C. cartridge package technology. The S.E.C. cartridge
contains the processor core, L2 cache and other components. The S.E.C. cartridge package
connects to the baseboard through an edge connector. Mechanical specifications for the processor
are given in this section. See Section 1.1.1 for a complete terminology listing.
Figure 24 shows the thermal plate side view and the cover side view of the Pentium III Xeon
processor. Figure 25 shows the Pentium III Xeon S.E.C. cartridge cooling solution attachment
feature details on the thermal plate and depict package form factor dimensions and retention
enabling features of the S.E.C. cartridge. The processor edge connector defined in this document is
referred to as SC330. See the SC330 connector specifications for further details on the edge
connector.
Datasheet
55
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 40 and Table 41 provide the edge finger and SC330 connector signal definitions for Pentium
III Xeon processors. The signal locations on the SC330 edge connector are to be used for signal
routing, simulation and component placement on the baseboard.
Figure 24. Isometric View of Pentium® III Xeon™ Processor S.E.C. Cartridge
NOTES:
Use of retention holes and retention indents are optional.
11.For SC330 connector specifications, see the 330-Contact Slot Connector (SC330) Design Guidelines.
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Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
3.000 ± .017
2.658 ±.035
Figure 25. S.E.C. Cartridge Cooling Solution Attach Details (Notes follow Figure 27)
Datasheet
57
Pentium® III Xeon™ Processor at 500 and 550 MHz
Figure 26. S.E.C. Cartridge Retention Enabling Details (Notes follow Figure 27)
.325 ± .004
5.350 ± .008
2X Ø .125 ± .002
2X .280 ± .009
6.000
58
+.015
- .008
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Figure 27. S.E.C. Cartridge Retention Enabling Details
.277 ±
.174
22
P
.919 ± .010
.189 2
4.840 ± .032
(FRONTSIDE HEIGHT)
P
4.777 ± .036
4.836 ± .008
(BACKSIDE HEIGHT)
.287 ± .016
.150 ± .010
SECTION P-P
.733 ± .013
SECTION F-F
NOTES
1. Maximum protrusion of the mechanical heatsink attach media into cartridge during assembly or in an
installed condition not to exceed 0.160" from external face of thermal plate.
2. Specified cover retention indent dimension is at the external end of the indent. Indent walls have 1.0 degree
draft, with the wider section on the external end.
3. Clip extension on internal surface of retention slots should be as little as possible and not to exceed 0.040".
12.Tapped holes for cooling solution attach. Max torque recommendation for a screw in tapped hole is 8±1 inch-lb.
Datasheet
59
Pentium® III Xeon™ Processor at 500 and 550 MHz
6.1
Weight
The maximum weight of a Pentium III Xeon processor is approximately 500 grams.
6.2
Cartridge to Connector Mating Details
The staggered edge connector layout of the Pentium III Xeon processor makes the processor
susceptible to damage from hot socketing (inserting the cartridge while power is applied to the
connector). Extra care should be taken to ensure hot socketing does not occur. The electrical and
mechanical integrity of the processor edge fingers are specified for up to 50 insertion/extraction
cycles.
Figure 28. Side View of Connector Mating Details
Z
Y
X
4.995 ± .036 4
10
FULLY INSTALLED
5 .049 ± .028
(.144)
NOTES:
4. Dimensional variation when cartridge is fully installed and the substrate is bottomed in the connector. Actual
system installed height and tolerance is subject to user’s manufacturing tolerance of SC330 connector to
baseboard.
5. Retention devices for this cartridge must accommodate this cartridge “Float” relative to connector, without
preload to the edge contacts in “X” and “Y” axes.
10.Fully installed dimensions must be maintained by the user’s retention device. Cartridge backout from fully
installed position may not exceed 0.020.
60
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Figure 29. Top View of Cartridge Insertion Pressure Points
Figure 30. Front View of Connector Mating Details
Z
Y
X
.168 ± .021
NOTE:
5. Retention devices for this cartridge must accommodate this cartridge “Float” relative to connector, without
preload to the edge contacts in “X” and “Y” axes.
Datasheet
61
Pentium® III Xeon™ Processor at 500 and 550 MHz
6.3
Pentium® III Xeon™ Processor Substrate Edge Finger
Signal Listing
Table 40 is the Pentium III Xeon processor substrate edge finger listing in order by pin number
Table 41 is the Pentium III Xeon processor substrate edge connector listing in order by pin name.
Table 40. Signal Listing in Order by Pin Number (Sheet 1 of 4)
Pin
No.
62
Pin Name
Signal Buffer Type
Pin
No.
Pin Name
Signal Buffer Type
A1
EMI
Connect to VSS
B1
PWR_EN[1]
Short to PWR_EN[0]
A2
VCC_TAP
TAP Supply
B2
VCC_CORE
CPU Core VCC
A3
EMI
Connect to VSS
B3
RESERVED_B3
DO NOT CONNECT
A4
VSS
Ground
B4
TEST_VSS_B4
Pull down to VSS
A5
VTT
AGTL+ VTT Supply
B5
VCC_CORE
CPU Core VCC
A6
VTT
AGTL+ VTT Supply
B6
VTT
AGTL+ VTT Supply
A7
SELFSB1
CMOS I/O
B7
VTT
AGTL+ VTT Supply
A8
VSS
Ground
B8
VCC_CORE
CPU Core VCC
DO NOT CONNECT
A9
SELFSB0
CMOS I/O
B9
RESERVED_B9
A10
VSS
Ground
B10
FLUSH#
CMOS Input
A11
TEST_VSS_A11
Pull down to VSS
B11
VCC_CORE
CPU Core VCC
A12
IERR#
CMOS Output
B12
SMI#
CMOS Input
A13
VSS
Ground
B13
INIT#
CMOS Input
A14
A20M#
CMOS Input
B14
VCC_CORE
CPU Core VCC
A15
FERR#
CMOS Output
B15
STPCLK#
CMOS Input
A16
VSS
Ground
B16
TCK
TAP Clock
A17
IGNNE#
CMOS Input
B17
VCC_CORE
CPU Core VCC
A18
TDI
TAP Input
B18
SLP#
CMOS Input
A19
VSS
Ground
B19
TMS
TAP Input
A20
TDO
TAP Output
B20
VCC_CORE
CPU Core VCC
A21
PWRGOOD
CMOS Input
B21
TRST#
TAP Input
A22
VSS
Ground
B22
RESERVED_B22
DO NOT CONNECT
A23
TEST_VCC_CORE_A23 Pull up to VCC_CORE
B23
VCC_CORE
CPU Core VCC
A24
THERMTRIP#
B24
RESERVED_B24
DO NOT CONNECT
DO NOT CONNECT
CMOS Output
A25
VSS
Ground
B25
RESERVED_B25
A26
RESERVED_A26
DO NOT CONNECT
B26
VCC_CORE
CPU Core VCC
A27
LINT[0]
CMOS Input
B27
TEST_VCC_CORE_B27
Pull up to VCC_CORE
A28
VSS
Ground
B28
LINT[1]
CMOS Input
A29
PICD[0]
CMOS I/O
B29
VCC_CORE
CPU Core VCC
A30
PREQ#
CMOS Input
B30
PICCLK
APIC Clock Input
A31
VSS
Ground
B31
PICD[1]
CMOS I/O
A32
BP#[3]
AGTL+ I/O
B32
VCC_CORE
CPU Core VCC
A33
BPM#[0]
AGTL+ I/O
B33
BP#[2]
AGTL+ I/O
A34
VSS
Ground
B34
RESERVED_B34
DO NOT CONNECT
A35
BINIT#
AGTL+ I/O
B35
VCC_CORE
CPU Core VCC
A36
DEP#[0]
AGTL+ I/O
B36
PRDY#
AGTL+ Output
A37
VSS
Ground
B37
BPM#[1]
AGTL+ I/O
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 40. Signal Listing in Order by Pin Number (Sheet 2 of 4)
Pin
No.
Datasheet
Pin Name
Signal Buffer Type
Pin
No.
Pin Name
Signal Buffer Type
A38
DEP#[1]
AGTL+ I/O
B38
VCC_CORE
CPU Core VCC
A39
DEP#[3]
AGTL+ I/O
B39
DEP#[2]
AGTL+ I/O
A40
VSS
Ground
B40
DEP#[4]
AGTL+ I/O
A41
DEP#[5]
AGTL+ I/O
B41
VCC_CORE
CPU Core VCC
A42
DEP#[6]
AGTL+ I/O
B42
DEP#[7]
AGTL+ I/O
A43
VSS
Ground
B43
D#[62]
AGTL+ I/O
A44
D#[61]
AGTL+ I/O
B44
VCC_CORE
CPU Core VCC
A45
D#[55]
AGTL+ I/O
B45
D#[58]
AGTL+ I/O
A46
VSS
Ground
B46
D#[63]
AGTL+ I/O
A47
D#[60]
AGTL+ I/O
B47
VCC_CORE
CPU Core VCC
AGTL+ I/O
A48
D#[53]
AGTL+ I/O
B48
D#[56]
A49
VSS
Ground
B49
D#[50]
AGTL+ I/O
A50
D#[57]
AGTL+ I/O
B50
VCC_CORE
CPU Core VCC
A51
D#[46]
AGTL+ I/O
B51
D#[54]
AGTL+ I/O
A52
VSS
Ground
B52
D#[59]
AGTL+ I/O
A53
D#[49]
AGTL+ I/O
B53
VCC_CORE
CPU Core VCC
A54
D#[51]
AGTL+ I/O
B54
D#[48]
AGTL+ I/O
A55
VSS
Ground
B55
D#[52]
AGTL+ I/O
A56
CPU_SENSE
Voltage Sense
B56
VCC_CORE
CPU Core VCC
A57
VSS
Ground
B57
L2_SENSE
Voltage Sense
A58
D#[42]
AGTL+ I/O
B58
VCC_CORE
CPU Core VCC
A59
D#[45]
AGTL+ I/O
B59
D#[41]
AGTL+ I/O
A60
VSS
Ground
B60
D#[47]
AGTL+ I/O
A61
D#[39]
AGTL+ I/O
B61
VCC_CORE
CPU Core VCC
A62
TEST_25_A62
Pull up to 2. 5V
B62
D#[44]
AGTL+ I/O
A63
VSS
Ground
B63
D#[36]
AGTL+ I/O
A64
D#[43]
AGTL+ I/O
B64
VCC_CORE
CPU Core VCC
A65
D#[37]
AGTL+ I/O
B65
D#[40]
AGTL+ I/O
A66
VSS
Ground
B66
D#[34]
AGTL+ I/O
A67
D#[33]
AGTL+ I/O
B67
VCC_CORE
CPU Core VCC
AGTL+ I/O
A68
D#[35]
AGTL+ I/O
B68
D#[38]
A69
VSS
Ground
B69
D#[32]
AGTL+ I/O
A70
D#[31]
AGTL+ I/O
B70
VCC_CORE
CPU Core VCC
A71
D#[30]
AGTL+ I/O
B71
D#[28]
AGTL+ I/O
A72
VSS
Ground
B72
D#[29]
AGTL+ I/O
A73
D#[27]
AGTL+ I/O
B73
VCC_CORE
CPU Core VCC
A74
D#[24]
AGTL+ I/O
B74
D#[26]
AGTL+ I/O
A75
VSS
Ground
B75
D#[25]
AGTL+ I/O
A76
D#[23]
AGTL+ I/O
B76
VCC_CORE
CPU Core VCC
A77
D#[21]
AGTL+ I/O
B77
D#[22]
AGTL+ I/O
A78
VSS
Ground
B78
D#[19]
AGTL+ I/O
A79
D#[16]
AGTL+ I/O
B79
VCC_CORE
CPU Core VCC
A80
D#[13]
AGTL+ I/O
B80
D#[18]
AGTL+ I/O
63
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 40. Signal Listing in Order by Pin Number (Sheet 3 of 4)
Pin
No.
64
Pin Name
Signal Buffer Type
Pin
No.
Pin Name
Signal Buffer Type
A81
VSS
Ground
B81
D#[20]
AGTL+ I/O
A82
TEST_VTT_A82
Pull up to VTT
B82
VCC_CORE
CPU Core VCC
A83
RESERVED_A83
DO NOT CONNECT
B83
RESERVED_B83
DO NOT CONNECT
A84
VSS
Ground
B84
RESERVED_B84
DO NOT CONNECT
A85
D#[11]
AGTL+ I/O
B85
VCC_CORE
CPU Core VCC
A86
D#[10]
AGTL+ I/O
B86
D#[17]
AGTL+ I/O
A87
VSS
Ground
B87
D#[15]
AGTL+ I/O
A88
D#[14]
AGTL+ I/O
B88
VCC_CORE
CPU Core VCC
A89
D#[09]
AGTL+ I/O
B89
D#[12]
AGTL+ I/O
A90
VSS
Ground
B90
D#[07]
AGTL+ I/O
A91
D#[08]
AGTL+ I/O
B91
VCC_CORE
CPU Core VCC
A92
D#[05]
AGTL+ I/O
B92
D#[06]
AGTL+ I/O
A93
VSS
Ground
B93
D#[04]
AGTL+ I/O
A94
D#[03]
AGTL+ I/O
B94
VCC_CORE
CPU Core VCC
A95
D#[01]
AGTL+ I/O
B95
D#[02]
AGTL+ I/O
A96
VSS
Ground
B96
D#[00]
AGTL+ I/O
A97
BCLK
System Bus Clock
B97
VCC_CORE
CPU Core VCC
A98
TEST_ VSS _A98
Pull down to VSS
B98
RESET#
AGTL+ Input
A99
VSS
Ground
B99
FRCERR
AGTL+ I/O
A100
BERR#
AGTL+ I/O
B100
VCC_CORE
CPU Core VCC
A101
A#[33]
AGTL+ I/O
B101
A#[35]
AGTL+ I/O
A102
VSS
Ground
B102
A#[32]
AGTL+ I/O
A103
A#[34]
AGTL+ I/O
B103
VCC_CORE
CPU Core VCC
A104
A#[30]
AGTL+ I/O
B104
A#[29]
AGTL+ I/O
A105
VSS
Ground
B105
A#[26]
AGTL+ I/O
A106
A#[31]
AGTL+ I/O
B106
VCC_L2
L2 Cache VCC
AGTL+ I/O
A107
A#[27]
AGTL+ I/O
B107
A#[24]
A108
VSS
Ground
B108
A#[28]
AGTL+ I/O
A109
A#[22]
AGTL+ I/O
B109
VCC_L2
L2 Cache VCC
A110
A#[23]
AGTL+ I/O
B110
A#[20]
AGTL+ I/O
A111
VSS
Ground
B111
A#[21]
AGTL+ I/O
A112
A#[19]
AGTL+ I/O
B112
VCC_L2
L2 Cache VCC
A113
A#[18]
AGTL+ I/O
B113
A#[25]
AGTL+ I/O
A114
VSS
Ground
B114
A#[15]
AGTL+ I/O
A115
A#[16]
AGTL+ I/O
B115
VCC_L2
L2 Cache VCC
A116
A#[13]
AGTL+ I/O
B116
A#[17]
AGTL+ I/O
A117
VSS
Ground
B117
A#[11]
AGTL+ I/O
A118
A#[14]
AGTL+ I/O
B118
VCC_L2
L2 Cache VCC
A119
VSS
Ground
B119
A#[12]
AGTL+ I/O
A120
A#[10]
AGTL+ I/O
B120
VCC_L2
L2 Cache VCC
A121
A#[05]
AGTL+ I/O
B121
A#[08]
AGTL+ I/O
A122
VSS
Ground
B122
A#[07]
AGTL+ I/O
A123
A#[09]
AGTL+ I/O
B123
VCC_L2
L2 Cache VCC
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 40. Signal Listing in Order by Pin Number (Sheet 4 of 4)
Pin
No.
Datasheet
Pin Name
Signal Buffer Type
Pin
No.
Pin Name
Signal Buffer Type
A124
A#[04]
AGTL+ I/O
B124
A#[03]
AGTL+ I/O
A125
VSS
Ground
B125
A#[06]
AGTL+ I/O
A126
RESERVED_A126
DO NOT CONNECT
B126
VCC_L2
L2 Cache VCC
A127
BNR#
AGTL+ I/O
B127
AERR#
AGTL+ I/O
A128
VSS
Ground
B128
REQ#[0]
AGTL+ I/O
A129
BPRI#
AGTL+ Input
B129
VCC_L2
L2 Cache VCC
A130
TRDY#
AGTL+ Input
B130
REQ#[1]
AGTL+ I/O
A131
VSS
Ground
B131
REQ#[4]
AGTL+ I/O
A132
DEFER#
AGTL+ Input
B132
VCC_L2
L2 Cache VCC
A133
REQ#[2]
AGTL+ I/O
B133
LOCK#
AGTL+ I/O
A134
VSS
Ground
B134
DRDY#
AGTL+ I/O
A135
REQ#[3]
AGTL+ I/O
B135
VCC_L2
L2 Cache VCC
A136
HITM#
AGTL+ I/O
B136
RS#[0]
AGTL+ Input
A137
VSS
Ground
B137
HIT#
AGTL+ I/O
A138
DBSY#
AGTL+ I/O
B138
VCC_L2
L2 Cache VCC
A139
RS#[1]
AGTL+ Input
B139
RS#[2]
AGTL+ Input
A140
VSS
Ground
B140
RP#
AGTL+ I/O
A141
BR2#
AGTL+ Input
B141
VCC_L2
L2 Cache VCC
A142
BR0#
AGTL+ I/O
B142
BR3#
AGTL+ Input
A143
VSS
Ground
B143
BR1#
AGTL+ Input
A144
ADS#
AGTL+ I/O
B144
VCC_L2
L2 Cache VCC
A145
AP#[0]
AGTL+ I/O
B145
RSP#
AGTL+ Input
A146
VSS
Ground
B146
AP#[1]
AGTL+ I/O
A147
VID_CORE[2]
Open or Short to VSS
B147
VCC_L2
L2 Cache VCC
A148
VID_CORE[1]
Open or Short to VSS
B148
WP
SMBus Input
A149
VSS
Ground
B149
VID_CORE[3]
Open or Short to VSS
A150
VID_CORE[4]
Open or Short to VSS
B150
VCC_L2
L2 Cache VCC
A151
SMBALERT#
SMBus Aler
B151
VID_CORE[0]
Open or Short to VSS
A152
VSS
Ground
B152
VID_L2[0]
Open or Short to VSS
A153
VID_L2[2]
Open or Short to VSS
B153
VCC_L2
L2 Cache VCC
A154
VID_L2[1]
Open or Short to VSS
B154
VID_L2[4]
Open or Short to VSS
A155
VSS
Ground
B155
VID_L2[3]
Open or Short to VSS
A156
VTT
AGTL+ VTT Supply
B156
VCC_L2
L2 Cache VCC
A157
VTT
AGTL+ VTT Supply
B157
VTT
AGTL+ VTT Supply
A158
VSS
Ground
B158
VTT
AGTL+ VTT Supply
A159
SA2
SMBus Input
B159
VCC_L2
L2 Cache VCC
A160
VCC_SM
SMBus Supply
B160
SMBCLK
SMBus Clock
A161
VSS
Ground
B161
SMBDA
SMBus Data
A162
SA1
SMBus Input
B162
VCC_L2
L2 Cache VCC
A163
SA0
SMBus Input
B163
RESERVED_B163
DO NOT CONNECT
A164
VSS
Ground
B164
EMI
Connect to VSS
A165
PWR_EN[0]
Short to PWR_EN[1]
B165
EMI
Connect to VSS
65
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 41. Signal Listing in Order by Pin
Name (Sheet 2 of 9)
Table 41. Signal Listing in Order by Pin
Name (Sheet 1 of 9)
Pin No.
66
Pin Name
Signal Buffer Type
Pin No.
Pin Name
Signal Buffer Typ
B124
A#[03]
AGTL+ I/O
A100
BERR#
AGTL+ I/O
A124
A#[04]
AGTL+ I/O
A35
BINIT#
AGTL+ I/O
A121
A#[05]
AGTL+ I/O
A127
BNR#
AGTL+ I/O
B125
A#[06]
AGTL+ I/O
B33
BP#[2]
AGTL+ I/O
B122
A#[07]
AGTL+ I/O
A32
BP#[3]
AGTL+ I/O
B121
A#[08]
AGTL+ I/O
A33
BPM#[0]
AGTL+ I/O
A123
A#[09]
AGTL+ I/O
B37
BPM#[1]
AGTL+ I/O
A120
A#[10]
AGTL+ I/O
A129
BPRI#
AGTL+ Input
B117
A#[11]
AGTL+ I/O
A142
BR0#
AGTL+ I/O
B119
A#[12]
AGTL+ I/O
B143
BR1#
AGTL+ Input
A116
A#[13]
AGTL+ I/O
A141
BR2#
AGTL+ Input
A118
A#[14]
AGTL+ I/O
B142
BR3#
AGTL+ Input
B114
A#[15]
AGTL+ I/O
A56
CPU_SENSE
Voltage Sense
A115
A#[16]
AGTL+ I/O
B96
D#[00]
AGTL+ I/O
B116
A#[17]
AGTL+ I/O
A95
D#[01]
AGTL+ I/O
A113
A#[18]
AGTL+ I/O
B95
D#[02]
AGTL+ I/O
A112
A#[19]
AGTL+ I/O
A94
D#[03]
AGTL+ I/O
B110
A#[20]
AGTL+ I/O
B93
D#[04]
AGTL+ I/O
B111
A#[21]
AGTL+ I/O
A92
D#[05]
AGTL+ I/O
A109
A#[22]
AGTL+ I/O
B92
D#[06]
AGTL+ I/O
A110
A#[23]
AGTL+ I/O
B90
D#[07]
AGTL+ I/O
B107
A#[24]
AGTL+ I/O
A91
D#[08]
AGTL+ I/O
B113
A#[25]
AGTL+ I/O
A89
D#[09]
AGTL+ I/O
B105
A#[26]
AGTL+ I/O
A86
D#[10]
AGTL+ I/O
A107
A#[27]
AGTL+ I/O
A85
D#[11]
AGTL+ I/O
B108
A#[28]
AGTL+ I/O
B89
D#[12]
AGTL+ I/O
B104
A#[29]
AGTL+ I/O
A80
D#[13]
AGTL+ I/O
A104
A#[30]
AGTL+ I/O
A88
D#[14]
AGTL+ I/O
A106
A#[31]
AGTL+ I/O
B87
D#[15]
AGTL+ I/O
B102
A#[32]
AGTL+ I/O
A79
D#[16]
AGTL+ I/O
A101
A#[33]
AGTL+ I/O
B86
D#[17]
AGTL+ I/O
A103
A#[34]
AGTL+ I/O
B80
D#[18]
AGTL+ I/O
B101
A#[35]
AGTL+ I/O
B78
D#[19]
AGTL+ I/O
A14
A20M#
CMOS Input
B81
D#[20]
AGTL+ I/O
A144
ADS#
AGTL+ I/O
A77
D#[21]
AGTL+ I/O
B127
AERR#
AGTL+ I/O
B77
D#[22]
AGTL+ I/O
A145
AP#[0]
AGTL+ I/O
A76
D#[23]
AGTL+ I/O
B146
AP#[1]
AGTL+ I/O
A74
D#[24]
AGTL+ I/O
A97
BCLK
System Bus Clock
B75
D#[25]
AGTL+ I/O
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 41. Signal Listing in Order by Pin
Name (Sheet 3 of 9)
Pin No.
Pin Name
Signal Buffer Type
Table 41. Signal Listing in Order by Pin
Name (Sheet 4 of 9)
Pin No.
Pin Name
Signal Buffer Typ
B74
D#[26]
AGTL+ I/O
A36
DEP#[0]
AGTL+ I/O
A73
D#[27]
AGTL+ I/O
A38
DEP#[1]
AGTL+ I/O
B71
D#[28]
AGTL+ I/O
B39
DEP#[2]
AGTL+ I/O
B72
D#[29]
AGTL+ I/O
A39
DEP#[3]
AGTL+ I/O
A71
D#[30]
AGTL+ I/O
B40
DEP#[4]
AGTL+ I/O
A70
D#[31]
AGTL+ I/O
A41
DEP#[5]
AGTL+ I/O
B69
D#[32]
AGTL+ I/O
A42
DEP#[6]
AGTL+ I/O
A67
D#[33]
AGTL+ I/O
B42
DEP#[7]
AGTL+ I/O
B66
D#[34]
AGTL+ I/O
B134
DRDY#
AGTL+ I/O
A68
D#[35]
AGTL+ I/O
A1
EMI
Connect to VSS
B63
D#[36]
AGTL+ I/O
A3
EMI
Connect to VSS
A65
D#[37]
AGTL+ I/O
B164
EMI
Connect to VSS
B68
D#[38]
AGTL+ I/O
B165
EMI
Connect to VSS
A61
D#[39]
AGTL+ I/O
A15
FERR#
CMOS Output
B65
D#[40]
AGTL+ I/O
B10
FLUSH#
CMOS Input
B59
D#[41]
AGTL+ I/O
B99
FRCERR
AGTL+ I/O
A58
D#[42]
AGTL+ I/O
B137
HIT#
AGTL+ I/O
A64
D#[43]
AGTL+ I/O
A136
HITM#
AGTL+ I/O
B62
D#[44]
AGTL+ I/O
A12
IERR#
CMOS Output
A59
D#[45]
AGTL+ I/O
A17
IGNNE#
CMOS Input
A51
D#[46]
AGTL+ I/O
B13
INIT#
CMOS Input
B60
D#[47]
AGTL+ I/O
A27
LINT[0]
CMOS Input
B54
D#[48]
AGTL+ I/O
B28
LINT[1]
CMOS Input
A53
D#[49]
AGTL+ I/O
B133
LOCK#
AGTL+ I/O
B49
D#[50]
AGTL+ I/O
B57
L2_SENSE
Voltage Sense
A54
D#[51]
AGTL+ I/O
B30
PICCLK
APIC Clock Input
B55
D#[52]
AGTL+ I/O
A29
PICD[0]
CMOS I/O
A48
D#[53]
AGTL+ I/O
B31
PICD[1]
CMOS I/O
B51
D#[54]
AGTL+ I/O
B36
PRDY#
AGTL+ Output
A45
D#[55]
AGTL+ I/O
A30
PREQ#
CMOS Input
B48
D#[56]
AGTL+ I/O
A165
PWR_EN[0]
Short to PWR_EN[1]
A50
D#[57]
AGTL+ I/O
B1
PWR_EN[1]
Short to PWR_EN[0]
B45
D#[58]
AGTL+ I/O
A21
PWRGOOD
CMOS Input
B52
D#[59]
AGTL+ I/O
B128
REQ#[0]
AGTL+ I/O
A47
D#[60]
AGTL+ I/O
B130
REQ#[1]
AGTL+ I/O
A44
D#[61]
AGTL+ I/O
A133
REQ#[2]
AGTL+ I/O
B43
D#[62]
AGTL+ I/O
A135
REQ#[3]
AGTL+ I/O
B46
D#[63]
AGTL+ I/O
B131
REQ#[4]
AGTL+ I/O
A138
DBSY#
AGTL+ I/O
A126
RESERVED_A126
DO NOT CONNECT
A132
DEFER#
AGTL+ Input
A26
RESERVED_A26
DO NOT CONNECT
Datasheet
67
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 41. Signal Listing in Order by Pin
Name (Sheet 5 of 9)
Pin No.
A83
68
Pin Name
RESERVED_A83
Signal Buffer Type
Table 41. Signal Listing in Order by Pin
Name (Sheet 6 of 9)
Pin No.
Pin Name
Signal Buffer Typ
DO NOT CONNECT
B21
TRST#
TAP Input
B163
RESERVED_B163
DO NOT CONNECT
B100
VCC_CORE
CPU Core VCC
B22
RESERVED_B22
DO NOT CONNECT
B103
VCC_CORE
CPU Core VCC
B24
RESERVED_B24
DO NOT CONNECT
B11
VCC_CORE
CPU Core VCC
B25
RESERVED_B25
DO NOT CONNECT
B14
VCC_CORE
CPU Core VCC
B3
RESERVED_B3
DO NOT CONNECT
B17
VCC_CORE
CPU Core VCC
B34
RESERVED_B34
DO NOT CONNECT
B2
VCC_CORE
CPU Core VCC
B83
RESERVED_B83
DO NOT CONNECT
B20
VCC_CORE
CPU Core VCC
B84
RESERVED_B84
DO NOT CONNECT
B23
VCC_CORE
CPU Core VCC
B9
RESERVED_B9
DO NOT CONNECT
B26
VCC_CORE
CPU Core VCC
B98
RESET#
AGTL+ Input
B29
VCC_CORE
CPU Core VCC
B140
RP#
AGTL+ I/O
B32
VCC_CORE
CPU Core VCC
B136
RS#[0]
AGTL+ Input
B35
VCC_CORE
CPU Core VCC
A139
RS#[1]
AGTL+ Input
B38
VCC_CORE
CPU Core VCC
B139
RS#[2]
AGTL+ Input
B41
VCC_CORE
CPU Core VCC
B145
RSP#
AGTL+ Input
B44
VCC_CORE
CPU Core VCC
A163
SA0
SMBus Input
B47
VCC_CORE
CPU Core VCC
A162
SA1
SMBus Input
B5
VCC_CORE
CPU Core VCC
A159
SA2
SMBus Input
B50
VCC_CORE
CPU Core VCC
A9
SELFSB0
CMOS I/O
B53
VCC_CORE
CPU Core VCC
A7
SELFSB1
CMOS I/O
B56
VCC_CORE
CPU Core VCC
B18
SLP#
CMOS Input
B58
VCC_CORE
CPU Core VCC
A151
SMBALERT#
SMBus Aler
B61
VCC_CORE
CPU Core VCC
B160
SMBCLK
SMBus Clock
B64
VCC_CORE
CPU Core VCC
B161
SMBDA
SMBus I/O
B67
VCC_CORE
CPU Core VCC
B12
SMI#
CMOS Input
B70
VCC_CORE
CPU Core VCC
B15
STPCLK#
CMOS Input
B73
VCC_CORE
CPU Core VCC
B16
TCK
TAP Clock
B76
VCC_CORE
CPU Core VCC
A18
TDI
TAP Input
B79
VCC_CORE
CPU Core VCC
A20
TDO
TAP Output
B8
VCC_CORE
CPU Core VCC
A62
TEST_25_A62
Pull up to 2. 5V
B82
VCC_CORE
CPU Core VCC
A23
TEST_VCC_CORE_A23
Pull up to VCC_CORE
B85
VCC_CORE
CPU Core VCC
B27
TEST_VCC_CORE_B27
Pull up to VCC_CORE
B88
VCC_CORE
CPU Core VCC
A11
TEST_VSS_A11
Pull down to VSS
B91
VCC_CORE
CPU Core VCC
A98
TEST_VSS_A98
Pull down to VSS
B94
VCC_CORE
CPU Core VCC
B4
TEST_VSS_B4
Pull down to VSS
B97
VCC_CORE
CPU Core VCC
A82
TEST_VTT_A82
Pull up to VTT
B106
VCC_L2
L2 Cache VCC
A24
THERMTRIP#
CMOS Output
B109
VCC_L2
L2 Cache VCC
B19
TMS
TAP Input
B112
VCC_L2
L2 Cache VCC
A130
TRDY#
AGTL+ Input
B115
VCC_L2
L2 Cache VCC
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 41. Signal Listing in Order by Pin
Name (Sheet 7 of 9)
Pin No.
Pin Name
Signal Buffer Type
Table 41. Signal Listing in Order by Pin
Name (Sheet 8 of 9)
Pin No.
Pin Name
Signal Buffer Typ
B118
VCC_L2
L2 Cache V CC
A131
VSS
Ground
B120
VCC_L2
L2 Cache V CC
A134
VSS
Ground
B123
VCC_L2
L2 Cache V CC
A137
VSS
Ground
B126
VCC_L2
L2 Cache V CC
A140
VSS
Ground
B129
VCC_L2
L2 Cache V CC
A143
VSS
Ground
B132
VCC_L2
L2 Cache V CC
A146
VSS
Ground
B135
VCC_L2
L2 Cache V CC
A149
VSS
Ground
B138
VCC_L2
L2 Cache V CC
A152
VSS
Ground
B141
VCC_L2
L2 Cache V CC
A155
VSS
Ground
B144
VCC_L2
L2 Cache V CC
A158
VSS
Ground
B147
VCC_L2
L2 Cache V CC
A16
VSS
Ground
B150
VCC_L2
L2 Cache V CC
A161
VSS
Ground
B153
VCC_L2
L2 Cache V CC
A164
VSS
Ground
B156
VCC_L2
L2 Cache V CC
A19
VSS
Ground
B159
VCC_L2
L2 Cache V CC
A22
VSS
Ground
B162
VCC_L2
L2 Cache V CC
A25
VSS
Ground
A160
VCC_SM
SMBus Supply
A28
VSS
Ground
A2
VCC_TAP
TAP Supply
A31
VSS
Ground
B151
VID_CORE[0]
Open or Short to VSS
A34
VSS
Ground
A148
VID_CORE[1]
Open or Short to VSS
A37
VSS
Ground
A147
VID_CORE[2]
Open or Short to VSS
A4
VSS
Ground
B149
VID_CORE[3]
Open or Short to VSS
A40
VSS
Ground
A150
VID_CORE[4]
Open or Short to VSS
A43
VSS
Ground
B152
VID_L2[0]
Open or Short to VSS
A46
VSS
Ground
A154
VID_L2[1]
Open or Short to VSS
A49
VSS
Ground
A153
VID_L2[2]
Open or Short to VSS
A52
VSS
Ground
B155
VID_L2[3]
Open or Short to VSS
A55
VSS
Ground
B154
VID_L2[4]
Open or Short to VSS
A57
VSS
Ground
A10
VSS
Ground
A60
VSS
Ground
A102
VSS
Ground
A63
VSS
Ground
A105
VSS
Ground
A66
VSS
Ground
A108
VSS
Ground
A69
VSS
Ground
A111
VSS
Ground
A72
VSS
Ground
A114
VSS
Ground
A75
VSS
Ground
A117
VSS
Ground
A78
VSS
Ground
A119
VSS
Ground
A8
VSS
Ground
A122
VSS
Ground
A81
VSS
Ground
A125
VSS
Ground
A84
VSS
Ground
A128
VSS
Ground
A87
VSS
Ground
A13
VSS
Ground
A90
VSS
Ground
Datasheet
69
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 41. Signal Listing in Order by Pin
Name (Sheet 9 of 9)
Pin No.
70
Pin Name
Signal Buffer Type
A93
VSS
Ground
A96
VSS
Ground
A99
VSS
Ground
A156
VTT
AGTL+ VTT Supply
A157
VTT
AGTL+ VTT Supply
A5
VTT
AGTL+ VTT Supply
A6
VTT
AGTL+ VTT Supply
B157
VTT
AGTL+ VTT Supply
B158
VTT
AGTL+ VTT Supply
B6
VTT
AGTL+ VTT Supply
B7
VTT
AGTL+ VTT Supply
B148
WP
SMBus Input
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
7.0
Boxed Processor Specifications
7.1
Introduction
The Pentium III Xeon processor is also offered as an Intel boxed processor. Intel boxed processors
are intended for system integrators who build systems from baseboards and off-the-shelf
components. The boxed Pentium III Xeon processor is supplied with an attached passive heatsink.
This section documents baseboard and system requirements for the heatsink that will be supplied
with the boxed Pentium III Xeon processor. This section is particularly important for OEMs that
manufacture baseboards for system integrators. Unless otherwise noted, all figures in this chapter
are dimensioned in inches. Figure 31 shows a mechanical representation of the boxed Pentium III
Xeon processor.
Figure 31. Boxed Pentium® III Xeon™ Processor
7.2
Mechanical Specifications
This section documents the mechanical specifications of the boxed Pentium III Xeon processor
heatsink.
The boxed processor ships with an attached passive heatsink. Clearance is required around the
heatsink to ensure proper installation of the processor and unimpeded airflow for proper cooling.
The space requirements and dimensions for the boxed processor are shown in Figure 32 (Side
View), Figure 33 (Front View), and Table 42. All dimensions are in inches.
Datasheet
71
Pentium® III Xeon™ Processor at 500 and 550 MHz
Figure 32. Side View Space Requirements for the Boxed Processor
A
B
72
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Figure 33. Front View Space Requirements for the Boxed Processor
D
C
7.2.1
Boxed Processor Heatsink Dimensions
Table 42. Boxed Processor Heatsink Dimensions
Fig. Ref. Label
7.2.2
Dimensions (Inches)
Min
Typ
A
Heatsink Depth (off heatsink attach point)
1.025
B
Heatsink Height (above baseboard
0.626
C
Heatsink Height (see front view)
4.235
D
Heatsink Width (see front view)
5.05
Max
Boxed Processor Heatsink Weight
The boxed processor heatsink will not weigh more than 350 grams.
7.2.3
Boxed Processor Retention Mechanism
The boxed Pentium III Xeon processor requires a retention mechanism that supports and secures
the Single Edge Contact Cartridge (S.E.C.C.) in the 330-contact slot connector. An S.E.C.C.
retention mechanism is not provided with the boxed processor. Baseboards designed for use by
Datasheet
73
Pentium® III Xeon™ Processor at 500 and 550 MHz
system integrators should include a retention mechanism and appropriate installation instructions.
The boxed Pentium III Xeon processor does not require additional heatsink supports. Heatsink
supports will not ship with the boxed Pentium III Xeon processor.
7.3
Thermal Specifications
This section describes the cooling requirements of the heatsink solution utilized by the boxed
processor.
7.3.1
Boxed Processor Cooling Requirements
The boxed processor passive heatsink requires airflow horizontally across the heatsink to cool the
processor. The boxed processor heatsink will keep the processor thermal plate temperature,
TPLATE, within the specifications, provided adequate airflow is directed into the system chassis,
across the heatsink and out of the system chassis. System integrators should perform thermal
testing using thermocouples (see Section 5.2) to evaluate the thermal efficiency of the system.
Alternately, system integrators may use software to monitor the thermal information available via
the Processor Information ROM and thermal sensor (see Section 4.3) to evaluate the thermal
efficiency of the system.
7.3.2
Optional Auxiliary Fan Attachment
The boxed processor’s passive heatsink includes features that allow for attachment of a standard
40mm auxiliary fan (with 36mm mounting hole spacing) to improve airflow over the passive
heatsink. System integrators must evaluate the thermal performance of their system (see above) and
consider the baseboard manufacturer’s recommendations for thermal management before deciding
if an auxiliary fan is warranted. If an auxiliary fan is needed (e.g., for the front processor in a
multiprocessor system), it may be attached to the face of the boxed processor’s passive heatsink. To
facilitate this, the boxed processor’s passive heatsink includes features in the heatsink fins (see
Figure 35 and Figure 36) onto which fan mounting hardware (grommets and screws) can be
attached. Two grommets and four screws (two different lengths to accommodate different fan
thicknesses) are included with the boxed Pentium III Xeon processor. The boxed Pentium III Xeon
processor does not ship with an auxiliary fan. Specifications for the heatsink features are shown in
Figure 36.
74
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Figure 34. Front Views of the Boxed Processor with Attached Auxiliary Fan (Not Included with
Boxed Processor)
Figure 35. Front View of Boxed Processor Heatsink with Fan Attach Features (Fan Not
Included)
1.26
Datasheet
75
Pentium® III Xeon™ Processor at 500 and 550 MHz
Figure 36. Cross-sectional View of Grommet Attach Features in the Heatsink (Grommet
Shown)
7.3.2.1
Clearance Recommendations for Auxiliary Fan
If an auxiliary fan is used, clearance must be provided in front of the boxed processor passive
heatsink to accommodate the mechanical and airflow clearance requirements of the fan and
mounting hardware. Baseboard-mounted components and chassis members should not violate the
clearance requirements for the auxiliary fan. Figure 37 and Figure 38 shows the clearance
recommended for a standard 40mm fan and air inlet. Required airspace clearance for fans may vary
by manufacturer. Consult your fan documentation and/or fan manufacturer for airspace
specifications.
Figure 37. Side View Space Recommendation for the Auxiliary Fan
.24
1.5
76
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Figure 38. Front View Space Recommendations for the Auxiliary Fan
7.3.2.2
Fan Power Recommendations for Auxiliary Fan
To facilitate power to the auxiliary fan and provide fan monitoring, a fan-sense capable power
header may be provided on the baseboard near every processor that may need an auxiliary fan.
Although the boxed processor does not ship with an auxiliary fan, it is highly recommended that a
power header be provided. It is also recommended that the power header be consistent with the
power header for other boxed processors that feature a fan-sense capable fan heatsink. Figure 39
shows the boxed processor fan/heatsink power cable connector. Table 43 shows the boxed
processor fan power cable connector requirements.
Figure 39. Boxed Processor Fan/Heatsink Power Cable Connector Description
Pin
Signal
1
GND
Straight square pin, 3-pin terminal housing with
polarizing ribs and friction locking ramp
2
+12V
0.100" pin pitch, 0.025" square pin width.
3
SENSE
Waldom*/Molex* P/N 22-01-3037 or equivalent.
Match with straight pin, friction lock header on motherboard
Waldom/Molex P/N 22-23-2031, AMP* P/N 640456-3,
or equivalent.
1
Datasheet
2
3
77
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 43. Fan/Heatsink Power and Signal Specifications
Description
+12 V: 12 volt fan power supply
Min
Typ
7V
12 V
IC: Fan current draw
SENSE: SENSE frequency (baseboard should pull this pin up to
appropriate VCC with resistor (typically 12 kΩ)
7.3.2.3
Max
13. 8V
100 mA
2 pulses per fan
revolution
Thermal Evaluation for Auxiliary Fan
Given the complex and unique nature of baseboard layouts, and the special chassis required to
support them, thermal performance may vary greatly with each baseboard/chassis combination.
Baseboard manufacturers must evaluate and recommend effective thermal solutions for their
specific designs, particularly designs that are proprietary or have nonstandard layouts. Such
thermal solutions must take all system components into account. The power requirements of all
processors that will be supported by the baseboard should be accommodated. The boxed Pentium
III Xeon processor is designed to provide a flexible cooling solution, including the option to attach
an auxiliary fan. Should the system thermal evaluation warrant the requirement for an auxiliary
fan, an auxiliary fan must be included with the baseboard to allow the thermal requirements of the
system to be met.
8.0
Integration Tools
The integration tool set for the Pentium III Xeon processor system designs will include an In-Target
Probe (ITP) for program execution control, register/memory/IO access, and breakpoint control.
This tool provides functionality commonly associated with debuggers and emulators. An ITP uses
the on-chip debug features of the Pentium III Xeon processor to provide program execution control.
Use of an ITP will not affect the high speed operations of the processor signals, ensuring the
system can operate at full speed with an ITP attached.
This document describes an ITP as well as a number of technical issues that must be taken into
account when including an ITP and logic analyzer interconnect tools in a debug strategy. The tool
descriptions that follow are meant to be nonexclusive and refer to the internal Intel ITP tool as well
as third party vendor ITP tools. Thus, the tools mentioned should not be considered as Intel's tools,
but as debug tools in the generic sense.
In general, the information in this chapter may be used as a basis for including integration tools in
any Pentium III Xeon processor-based system designs. The logic analyzer interconnect tool keepout zones described in this chapter should be used as general guidelines for Pentium III Xeon
processor system designs.
8.1
In-Target Probe (ITP) for Pentium ® III Xeon™ Processors
An In-Target Probe (ITP) for Pentium III Xeon processor is a debug tool which allows access to onchip debug features via a small port on the system board called the debug port. An ITP
communicates to the processor through the debug port using a combination of hardware and
software. The software is Windows NT 4.0 running on a host PC. The hardware consists of a PCI
board in the host PC connected to the signals which make up the Pentium III Xeon processor's
78
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
debug interface. Due to the nature of an ITP, the processor may be controlled without affecting any
high speed signals. This ensures that the system can operate at full speed with an ITP attached.
Intel will use an ITP for internal debug and system validation and recommends that all
Pentium III Xeon processor-based system designs include a debug port. This is especially
important if Intel assistance is required in debugging a system-processor interrelationship issue.
8.1.1
Primary Function
The primary function of an ITP is to provide a control and query interface for one or more
processors. With an ITP, one can control program execution and have the ability to access
processor registers, system memory and I/O. Thus, one can start and stop program execution using
a variety of breakpoints, single-step the program at the assembly code level, as well as read and
write registers, memory and I/O. The on-chip debug features will be controlled from a Windows
NT 4.0 software application running on a Pentium or P6 family processor-based PC with a PCI
card slot. (See Figure 40.)
Figure 40. Hardware Components of an ITP
PCI Add-In Card
2m Cabl
Plugs in to your host PC (12.5 in.)
2 in. Cabl
Debug Port
Connector
Connects to Debug
Port on target board
Buffer Board
8.1.2
Debug Port Connector Description
An ITP will connect to the system through the debug port. Recommended connectors, to mate an
ITP cable with the debug port on the board, are available in either a vertical or right-angle
configuration. Both configurations fit into the same board footprint. The connectors are
manufactured by AMP Incorporated and are in the AMPMODU System 50 line. Following are the
AMP part numbers for the two connectors:
• Amp 30-pin shrouded vertical header: 104068-3
• Amp 30-pin shrouded right-angle header: 104069-5
Note:
Datasheet
These are high density through hole connectors with pins on 0.050 in. by 0.100 in. centers. Do not
confuse these with the more common 0.100 in. by 0.100 in. center headers.
The debug port must be mounted on the system baseboard; the processor does not contain a
debug port.
79
Pentium® III Xeon™ Processor at 500 and 550 MHz
8.1.3
Debug Port Signal Descriptions
Table 44 describes the debug port signals and provides the pin assignment.
Table 44. Debug Port Pinout Description and Requirements
Name
RESET#
Pin
1
1
(Sheet 1 of 3)
Description
Specification
Requirement
Reset signal from MP
cluster to ITP.
Terminate2 signal properly
at the debug port
Debug port must be at the
end of the signal trace
DBRESET#
3
Allows ITP to reset
entire target system.
Tie signal to target syste
reset (recommendation:
PWR OK signal on PCIset
as an Ored input
Pulled-up signal with the
proper resistor (see notes)
TCK
TMS
5
7
TheTAP (Test Access
Port) clock from ITP
to MP cluster.
Test mode select
signal from ITP to MP
cluster, controls the
TAP finite state
machine.
Add 1.0 kW pull-up resistor
to VCCTAP near driver
For MP systems, each
processor should receive a
separately buffered TCK.
Connected to high speed
comparator (biased at 2/3 of
the level found at the
POWERON pin) on an ITP
buffer board. Additional load
does not change timing
calculations for the processor
bus agents if routed properly.
Open drain output from ITP to
the target system. It will be
held asserted for 100 ms;
capacitance needs to be small
enough to recognize assert.
The pull-up resistor should be
picked to (1) meet VIL of
target system and (2) meet
specified rise time.
Poor routing can cause
multiple clocking problems.
Should be routed to all
components in the boundary
scan.3
Add a series termination
(UP) resistor or a Bessel
filter (MP) on each output.
Simulations must be run to
determine proper value fo
series termination (UP) o
Bessel filter (MP)
Add 1.0 kW pull-up resistor
to VCCTAP near driver
Operates synchronously with
TCK. Should be routed to all
components in the boundary
scan.3
For MP systems, each
processor should receive a
separately buffered TMS.
Add a series termination
resistor on each output.
80
Notes
Simulations should be run t
determine the proper value for
series termination.
TDI
8
Test data input signal
from ITP to first
component in
boundary scan chain
of MP cluster; inputs
test instructions and
data serially.
This signal is open-drain
from an ITP. However, TDI
is pulled up to VCCTAP with
~150W on the Pentium ® III
Xeon™ processor. Add a
150 to 330W pull-up
resistor (to VCCTAP) if TDI
will not be connected
directly to a processor.
Operates synchronously with
TCK.
POWERON
9
Used by ITP to
determine when
target system power
is ON and, once
target system is ON,
enables all debug
port electrical
interface activity.
From target VTT to
ITP.
Add 1 kW pull-up resistor
(to VTT)
If no power is applied, an ITP
will not drive any signals;
isolation provided using
isolation gates. Voltage
applied is internally used to
set AGTL+ threshold (or
reference) at 2/3 VTT.
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 44. Debug Port Pinout Description and Requirements
Name
TDO
Pin
10
Description
Test data output
signal from last
component in
boundary scan chain
of MP cluster to ITP;
test output is read
serially.
1
(Sheet 2 of 3)
Specification
Requirement
Notes
Add 150W pull-up resistor
(to VCCTAP)
Operates synchronously with
TCK. Each Pentium III Xeo
processor have a 25W driver.
Design pull-ups to route
around empty processor
sockets (so resistors are
not in parallel)
DBINST#
11
Indicates to target
system that an ITP is
installed.
Add ~10 kW pull-up
resistor
Not required if boundary scan
is not used in target system.
TRST#
12
Test reset signal fro
ITP to MP cluster,
used to resetTAP
logic.
Add ~680W pull-down
Asynchronous input signal.
To disableTAP reset if ITP not
installed.
BSEN#
14
Informs target system
that ITP is using
boundary scan.
PREQ0#
16
PREQ0# signal,
driven by ITP, makes
requests to P0 to
enter debug.
Add 150 to 330W pull-up
resistor (to VCC2.5)
PRDY0#
18
PRDY0# signal,
driven by P0, informs
ITP that P0 is ready
for debug.
Terminate2 signal properly
at the debug port
Not required if boundary scan
is not used in target system.
Debug port must be at the
end of the signal trace
PREQ1#
20
PREQ1# signal from
ITP to P1.
Add 150 to 330W pull-up
resistor (to VCC2.5)
PRDY1#
22
PRDY1# signal fro
P1 to ITP.
Terminate2 signal properly
at the debug port
Debug port must be at the
end of the signal trace
PREQ2#
24
PREQ2# signal from
ITP to P2.
Add 150 to 330W pull-up
resistor (to VCC2.5)
PRDY2#
26
PRDY2# signal fro
ITP to P2 .
Terminate2 signal properly
at the debug port
Debug port must be at the
end of the signal trace
PREQ3#
Datasheet
28
PREQ3# signal from
ITP to P3.
Connected to high speed
comparator (biased at 2/3 of
the level found at the
POWERON pin) on an ITP
buffer board. Additional load
does not change timing
calculations for the processor
bus agents if routed properly.
Connected to high speed
comparator (biased at 2/3 of
the level found at the
POWERON pin) on an ITP
buffer board. Additional load
does not change timing
calculations for the processor
bus agents.
Connected to high speed
comparator (biased at 2/3 of
the level found at the
POWERON pin) on an ITP
buffer board. Additional load
does not change timing
calculations for the processor
bus agents if routed properly.
Add 150 to 330W pull-up
resistor (to VCC2.5)
81
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 44. Debug Port Pinout Description and Requirements
Name
PRDY3#
Pin
30
(Sheet 3 of 3)
Specification
Requirement
Description
PRDY3# signal fro
ITP to P3.
1
Notes
Terminate2 signal properly
at the debug port
Debug port must be at the
end of the signal trace
BCLK
29
Bus clock from the
MP cluster.
Use a separate driver to
drive signal to the debug
port.
Must be connected to
support future steppings of
the Pentium III Xeon
processors.
GND
2, 4, 6,
13, 15,
17, 19,
21, 23,
25, 27
Signal ground.
Connected to high speed
comparator (biased at 2/3 of
the level found at the
POWERON pin) on an ITP
buffer board. Additional load
does not change timing
calculations for the processor
bus agents if routed properly.
A separate driver should be
used to avoid loading issues
associated with having an ITP
either installed or not
installed.
Connect all pins to signal
ground
NOTES:
1. Resistor values with “~” preceding them can vary from the specified value; use resistor as close as possible
to the value specified.
2. Termination for these signals should include series (~240Ω) and GTL+ termination (conne cted to 1.5V)
resistors. See Figure 41.
3. Signal should be at end of daisy chain and the boundary scan chain should be partitioned into two distinct
sections to assist in debugging the system: one partition with only the processor(s) for system debug (i.e.,
used with an ITP) and another with all other components for manufacturing or system test.
8.1.4
Debug Port Signal Notes
In general, all open drain AGTL+ outputs from the system must be retained at a proper logic level,
whether or not the debug port is installed. RESET# from the processor system should be terminated
at the debug port, as shown in Figure 41. Rt should be a 150Ω on RESET#.
PRDYn# should have a similar layout, however R t should be 50Ω to match board impedance rather
than the normal 150Ω since there are only 2 loads on this signal.
Figure 41. AGTL+ Signal Termination
1.5V
Short Trac
Rt
Rs
L oad
L oad
D ebug
Port
RESET #
Sourc
R s = 240 Ω
82
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
8.1.4.1
General Signal Quality Notes
Signals from the debug port are fed to the system from an ITP via a buffer board and a cable. If
system signals routed to the debug port (i.e., TDO, PRDY[x]# and RESET#) are used elsewhere in
the system, then dedicated drivers should be used to isolate the signals from reflections coming
from the end of this cable. If the Pentium III Xeon processor boundary scan signals are used
elsewhere in the system, then the TDI, TMS, TCK, and TRST# signals from the debug port should
be isolated from the system signals.
In general, no signals should be left floating. Thus, signals going from the debug port to the
processor system should not be left floating. If they are left floating, there may be problems when
an ITP is not plugged into the connector.
8.1.4.2
Signal Note: DBRESET#
The DBRESET# output signal from an ITP is an open drain with about 5Ω of RDS. The usual
implementation is to connect it to the PWROK open drain signal on the PCIset components as an
OR input to initiate a system reset. In order for the DBRESET# signal to work properly, it must
actually reset the entire target system. The signal should be pulled up (Intel recommends a 240Ω
resistor, but system designers will need to fine tune specific system designs) to meet two
considerations: (1) the signal must be able to meet VIL of the system, and (2) it must allow the
signal to meet the specified rise time. When asserted by anITP, the DBRESET# signal will remain
asserted for 100 ms. A large capacitance should not be present on this signal as it may prevent a full
charge from building up within 100 ms.
8.1.4.3
Signal Note: TDO and TDI
The TDO signal of each processor has a 2.5V Tolerant open-drain driver. The TDI signal of each
processor contains a 150Ω pull-up to VCCTAP . When connecting one Pentium III Xeon processor
to the next, or connecting to the TDI of the first processor, no external pull-up is required. However,
the last processor of the chain does require a pull-up before passing the signal to the next device in
the chain.
8.1.4.4
Warning:
Datasheet
Signal Note: TCK
A significant number of target systems have had signal integrity issues with the TCK signal. TCK
is a critical clock signal and must be routed accordingly; make sure to observe power and ground
plane integrity for this signal. Follow the guidelines below and assure the quality of the signal when
beginning use of an ITP to debug your target.
A significant number of target systems using series terminations methods in MP systems
exhibited signal integrity problems on TCK which prevented the use of the debug port and
inhibited system debugging. In the paragraphs that follow, Intel has since suggested changing to a
simple LC (Bessel) Filter as a strongly suggested improvement to your target design. Bessel
filtering is not necessarily required for existing systems that are already working. This method
should, however, be used in all future debug port designs.
The use of buffering of the individual TCK lines in an MP system is a design requirement.
All the design suggestions and requirements that follow require the individual designer to
determine component values and TCK implementation success with the use of target design
simulations and/or testing.
83
Pentium® III Xeon™ Processor at 500 and 550 MHz
Due to the number of loads on the TCK signal, special care should be taken when routing this
signal on the baseboard. Poor routing can lead to multiple clocking of some agents on the debug
chain. This causes information to be lost through the chain and can result in bad commands being
issued to some agents on the chain.
The suggested routing scheme is to drive each agent's TCK signals individually from a buffer
device. Figure 42 shows how the TCK signal should be routed to the agents in a 4-way Pentium III
Xeon processor system incorporating the Intel® 450NX PCIset. A Bessel filter is recommended
over a series termination at the output of each buffer. The values shown in Figure 42 are only
examples. The designer should determine the LC values appropriate for their particular application.
If it is desired to ship production systems without the 2.5V b uffers installed, then pull-up
resistors should be placed at the outputs to prevent TCK from floating
Figure 42. TCK with Individual Buffering Scheme
P0
P1
P2
P3
2.5V Buffers
2.5V
Pull up Resistor
100 nH
56 pF
100 nH
56 pF
100 nH
TCK
56 pF
100 nH
56 pF
100 nH
Debug Port
56 pF
100 nH
56 pF To each NX device, other
JTAG ...
An ITP buffer board drives the TCK signal through the debug port to the buffer device.
84
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Note:
The buffer rise and fall edge rates should NOT be FASTER than 3ns. Edge rates faster than this in
the system can contribute to signal reflections which endanger ITP compatibility with the target
system.
A low voltage buffer capable of drivin g 2.5V outputs such asan 74LVQ244 is suggested to
eliminate the need for attenuation.
Simulation should be performed to verify that the edge rates of the buffer chosen are not too
fast.
The pull-up resistor to 2. 5V keeps the TCK signal from floating when an ITP is not connected.
The value of this resistor should be such that an ITP can still drive the signal low (~1kΩ). The trace
lengths from the buffer to each of the agents should also be kept at a minimum to ensure good
signal integrity.
The “synchronous” mode of an ITP, needed for debug of FRC pairs, is no longer supported. FRC
mode must be disabled when debugging an FRC-capable system.
8.1.5
Using Boundary Scan to Communicate to the Processor
An ITP communicates to Pentium III Xeon processors by stopping their execution and sending/
receiving messages over boundary scan pins. As long as each processor is tied into the system
boundary scan chain, an ITP can communicate with it. In the simplest case, the processors are back
to back in the scan chain, with the boundary scan input (TDI) of the first processor connected up
directly to the pin labeled TDI on the debug port and the boundary scan output of the last processor
connected up to the pin labeled TDO on the debug port as shown in Figure 43.
Figure 43. System Preferred Debug Port Layout
V CC TAP
TDO
TDI
Pentium ® II
Xeon™ Processor
TDO
TDI
Pentium II Xeon
Processor
TDO
TDI
Pentium II Xeon
Processor
TDO
TDI
Pentium II Xeon
Processor
TDI
TDO
TDI
TDO
TDI
TDO
Debug Port
(ITP)
Datasheet
PCIse
Component
PCIse
Component
Note: See previous
table for recommended
pull-up resistor values.
85
Pentium® III Xeon™ Processor at 500 and 550 MHz
8.2
Integration Tool (Logic Analyzer) Considerations
Target platforms must be designed to allow for the mechanical keep-out zones. These keep-outs
allow a logic analyzer interface to be plugged in between the processor slots. Intel now uses only
third party solutions for logic analyzers. The companies that Intel has enabled at the time of
publication have been Hewlett-Packard* and Tektronix*. Please contact these vendors for the latest
keep-out zone information.
9.0
Appendix
This appendix provides an alphabetical listing of all Pentium III Xeon processor signals and tables
that summarize the signals by direction: output, input, and I/O.
9.1
Alphabetical Signals Reference
This section provides an alphabetical listing of all Pentium III Xeon processor signals.
9.1.1
A[35:03]# (I/O)
The A[35:3]# (Address) signals define a 236-byte physical memory address space. When ADS# is
active, these pins transmit the address of a transaction; when ADS# is inactive, these pins transmit
transaction type information. These signals must connect the appropriate pins of all agents on the
Pentium III Xeon processor system bus. The A[35:24]# signals are parity-protected by the AP1#
parity signal, and the A[23:03]# signals are parity protected by the AP0# parity signal.
On the active-to-inactive transition of RESET#, the processors sample the A[35:03]# pins to
determine their power-on configuration. See the Pentium® II Processor Developer’s Manual for
details.
9.1.2
A20M# (I)
If the A20M# (Address-20 Mask) input signal is asserted, the Pentium III Xeon processor masks
physical address bit 20 (A20#) before looking up a line in any internal cache and before driving a
read/write transaction on the bus. Asserting A20M# emulates the 8086 processor's address wraparound at the 1-Mbyte boundary. Assertion of A20M# is only supported in real mode.
A20M# is an asynchronous signal. However, to ensure recognition of this signal following an I/O
write instruction, it must be valid along with the TRDY# assertion of the corresponding I/O Write
bus transaction.
During active RESET#, each processor begins sampling the A20M#, IGNNE#, and LINT[1:0]
values to determine the ratio of core-clock frequency to bus-clock frequency. See Table 1. On the
active-to-inactive transition of RESET#, each processor latches these signals and freezes the
frequency ratio internally. System logic must then release these signals for normal operation.
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Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
9.1.3
ADS# (I/O)
The ADS# (Address Strobe) signal is asserted to indicate the validity of the transaction address on
the A[35:03]# pins. All bus agents observe the ADS# activation to begin parity checking, protocol
checking, address decode, internal snoop, or deferred reply ID match operations associated with
the new transaction. This signal must connect the appropriate pins on all Pentium III Xeon
processor system bus agents.
9.1.4
AERR# (I/O)
The AERR# (Address Parity Error) signal is observed and driven by all Pentium III Xeon processor
system bus agents, and if used, must connect the appropriate pins on all Pentium III Xeon processor
system bus agents. AERR# observation is optionally enabled during power-on configuration; if
enabled, a valid assertion of AERR# aborts the current transaction.
If AERR# observation is disabled during power-on configuration, a central agent may handle an
assertion of AERR# as appropriate to the Machine Check Architecture (MCA) of the system.
9.1.5
AP[1:0]# (I/O)
The AP[1:0]# (Address Parity) signals are driven by the request initiator along with ADS#,
A[35:03]#, REQ[4:0]#, and RP#. AP1# covers A[35:24]#, and AP0# covers A[23:03]#. A correct
parity signal is high if an even number of covered signals are low and low if an odd number of
covered signals are low. This allows parity to be high when all the covered signals are high.
AP[1:0]# should connect the appropriate pins of all Pentium III Xeon processor system bus agents.
9.1.6
BCLK (I)
The BCLK (Bus Clock) signal determines the bus frequency. All Pentium III Xeon processor
system bus agents must receive this signal to drive their outputs and latch their inputs on the BCLK
rising edge.
All external timing parameters are specified with respect to the BCLK signal.
9.1.7
BERR# (I/O)
The BERR# (Bus Error) signal is asserted to indicate an unrecoverable error without a bus protocol
violation. It may be driven by all Pentium III Xeon processor system bus agents, and must connect
the appropriate pins of all such agents, if used. However, Pentium III Xeon processors do not
observe assertions of the BERR# signal.
BERR# assertion conditions are configurable at a system level. Assertion options are defined by
the following options:
•
•
•
•
Datasheet
Enabled or disabled.
Asserted optionally for internal errors along with IERR#.
Asserted optionally by the request initiator of a bus transaction after it observes an error.
Asserted by any bus agent when it observes an error in a bus transaction.
87
Pentium® III Xeon™ Processor at 500 and 550 MHz
9.1.8
BINIT# (I/O)
The BINIT# (Bus Initialization) signal may be observed and driven by all Pentium III Xeon
processor system bus agents, and if used must connect the appropriate pins of all such agents. If the
BINIT# driver is enabled during power on configuration, BINIT# is asserted to signal any bus
condition that prevents reliable future information.
If BINIT# observation is enabled during power-on configuration, and BINIT# is sampled asserted,
all bus state machines are reset and any data which was in transit is lost. All agents reset their
rotating ID for bus arbitration to the state after reset, and internal count information is lost. The L1
and L2 caches are not affected.
If BINIT# observation is disabled during power-on configuration, a central agent may handle an
assertion of BINIT# as appropriate to the Machine Check Architecture (MCA) of the system.
9.1.9
BNR# (I/O)
The BNR# (Block Next Request) signal is used to assert a bus stall by any bus agent who is unable
to accept new bus transactions. During a bus stall, the current bus owner cannot issue any new
transactions.
Since multiple agents might need to request a bus stall at the same time, BNR# is a wire-OR signal
which must connect the appropriate pins of all Pentium III Xeon processor system bus agents. In
order to avoid wire-OR glitches associated with simultaneous edge transitions driven by multiple
drivers, BNR# is activated on specific clock edges and sampled on specific clock edges.
9.1.10
BP[3:2]# (I/O)
The BP[3:2]# (Breakpoint) signals are outputs from the processor that indicate the status of
breakpoints.
9.1.11
BPM[1:0]# (I/O)
The BPM[1:0]# (Breakpoint Monitor) signals are breakpoint and performance monitor signals.
They are outputs from the processor which indicate the status of breakpoints and programmable
counters used for monitoring processor performance.
9.1.12
BPRI# (I)
The BPRI# (Bus Priority Request) signal is used to arbitrate for ownership of the Pentium III Xeon
processor system bus. It must connect the appropriate pins of all Pentium III Xeon processor system
bus agents. Observing BPRI# active (as asserted by the priority agent) causes all other agents to
stop issuing new requests, unless such requests are part of an ongoing locked operation. The
priority agent keeps BPRI# asserted until all of its requests are completed, then releases the bus by
deasserting BPRI#.
9.1.13
BR0# (I/O), BR[3:1]# (I)
The BR[3:1]# (Bus Request) pins drive the BREQ[3:0]# signals on the system. The BR[3:0]# pins
are interconnected in a rotating manner to other processors’ BR[3:0]# pins. Table 45 gives the
rotating interconnect between the processor and bus signals for 4-way systems.
88
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 45. BR[3:0]# Signals Rotating Interconnect, 4-Way System
Bus Signal
Agent 0 Pins
Agent 1 Pins
Agent 2 Pins
Agent 3 Pins
BREQ0#
BR0#
BR3#
BR2#
BR1#
BREQ1#
BR1#
BR0#
BR3#
BR2#
BREQ2#
BR2#
BR1#
BR0#
BR3#
BREQ3#
BR3#
BR2#
BR1#
BR0#
Table 46 gives the interconnect between the processor and bus signals for a 2-way system.
Table 46. BR[3:0]# Signals Rotating Interconnect, 2-Way System
Bus Signal
Agent 0 Pins
Agent 1 Pins
BREQ0#
BR0#
BR3#
BREQ1#
BR1#
BR0#
BREQ2#
BR2#
BR1#
BREQ3#
BR3#
BR2#
During power-up configuration, the central agent must assert its BR0# signal. All symmetric agents
sample their BR[3:0]# pins on active-to-inactive transition of RESET#. The pin on which the agent
samples an active level determines its agent ID. All agents then configure their BREQ[3:0]# signals
to match the appropriate bus signal protocol, as shown in Table 47.
Table 47. Agent ID Configuration
9.1.14
BR0#
BR1#
BR2#
BR3#
A5#
Agent ID
L
H
H
H
H
0
H
H
H
L
H
1
H
H
L
H
H
2
H
L
H
H
H
3
L
H
H
H
L
0(master)
H
H
H
L
L
0(checker
H
H
L
H
L
2(master)
H
L
H
H
L
2(checker
CPU_SENSE
The CPU_SENSE pin is connected to the VCC_CORE power plane on the substrate.
9.1.15
D[63:00]# (I/O)
The D[63:00]# (Data) signals are the data signals. These signals provide a 64-bit data path between
the Pentium III Xeon processor system bus agents, and must connect the appropriate pins on all
such agents. The data driver asserts DRDY# to indicate a valid data transfer.
Datasheet
89
Pentium® III Xeon™ Processor at 500 and 550 MHz
9.1.16
DBSY# (I/O)
The DBSY# (Data Bus Busy) signal is asserted by the agent responsible for driving data on the
Pentium III Xeon processor system bus to indicate that the data bus is in use. The data bus is
released after DBSY# is deasserted. This signal must connect the appropriate pins on all Pentium
III Xeon processor system bus agents.
9.1.17
DEFER# (I)
The DEFER# signal is asserted by an agent to indicate that a transaction cannot be guaranteed inorder completion. Assertion of DEFER# is normally the responsibility of the addressed memory or
I/O agent. This signal must connect the appropriate pins of all Pentium III Xeon processor system
bus agents.
9.1.18
DEP[7:0]# (I/O)
The DEP[7:0]# (Data Bus ECC Protection) signals provide optional ECC protection for the data
bus. They are driven by the agent responsible for driving D[63:00]#, and must connect the
appropriate pins of all Pentium III Xeon processor system bus agents which use them. The
DEP[7:0]# signals are enabled or disabled for ECC protection during power on configuration.
9.1.19
DRDY# (I/O)
The DRDY# (Data Ready) signal is asserted by the data driver on each data transfer, indicating
valid data on the data bus. In a multi-cycle data transfer, DRDY# may be deasserted to insert idle
clocks. This signal must connect the appropriate pins of all Pentium III Xeon processor system bus
agents.
9.1.20
EMI
The EMI pins should be connected to baseboard or chassis ground through zero ohm resisters.
9.1.21
FERR# (O)
The FERR# (Floating-point Error) signal is asserted when the processor detects an unmasked
floating-point error. FERR# is similar to the ERROR# signal on the Intel387 coprocessor, and is
included for compatibility with systems using MS-DOS*-type floating-point error reporting.
9.1.22
FLUSH# (I)
When the FLUSH# input signal is asserted, processors write back all data in the Modified state
from their internal caches and invalidate all internal cache lines. At the completion of this
operation, the processor issues a Flush Acknowledge transaction. The processor does not cache any
new data while the FLUSH# signal remains asserted.
FLUSH# is an asynchronous signal. However, to ensure recognition of this signal following an I/O
write instruction, it must be valid along with the TRDY# assertion of the corresponding I/O Write
bus transaction.
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Pentium® III Xeon™ Processor at 500 and 550 MHz
On the active-to-inactive transition of RESET#, each processor samples FLUSH# to determine its
power-on configuration. See Pentium® II Processor Developer’s Manual for details.
9.1.23
FRCERR (I/O)
If two processors are configured in a Functional Redundancy Checking (FRC) master/checker pair,
as a single “logical” processor, the FRCERR (Functional Redundancy Checking Error) signal is
asserted by the checker if a mismatch is detected between the internally sampled outputs and the
master’s outputs. The checker's FRCERR output pin must be connected with the master's FRCERR
input pin in this configuration.
For point-to-point connections, the checker always compares against the master's outputs. For
bussed single-driver signals, the checker compares against the signal when the master is the only
allowed driver. For bussed multiple-driver wired-OR signals, the checker compares against the
signal only if the master is expected to drive the signal low
When a processor is configured as an FRC checker, FRCERR is toggled during its reset action. A
checker asserts FRCERR for approximately 1 second after the active-to-inactive transition of
RESET# if it executes its Built-In Self-Test (BIST). When BIST execution completes, the checker
processor deasserts FRCERR if BIST completed successfully, and continues to assert FRCERR if
BIST fails. If the checker processor does not execute the BIST action, then it keeps FRCERR
asserted for approximately 20 clocks and then deasserts it.
All asynchronous signals must be externally synchronized to BCLK by system logic during FRC
mode operation.
9.1.24
HIT# (I/O), HITM# (I/O)
The HIT# (Snoop Hit) and HITM# (Hit Modified) signals convey transaction snoop operation
results, and must connect the appropriate pins of all Pentium III Xeon processor system bus agents.
Any such agent may assert both HIT# and HITM# together to indicate that it requires a snoop stall,
which can be continued by reasserting HIT# and HITM# together.
9.1.25
IERR# (O)
The IERR# (Internal Error) signal is asserted by a processor as the result of an internal error.
Assertion of IERR# is usually accompanied by a SHUTDOWN transaction on the Pentium III Xeon
processor system bus. This transaction may optionally be converted to an external error signal (e.g.,
NMI) by system core logic. The processor will keep IERR# asserted until it is handled in software,
or with the assertion of RESET#, BINIT#, or INIT#.
9.1.26
IGNNE# (I)
The IGNNE# (Ignore Numeric Error) signal is asserted to force the processor to ignore a numeric
error and continue to execute noncontrol floating-point instructions. If IGNNE# is deasserted, the
processor generates an exception on a noncontrol floating-point instruction if a previous floatingpoint instruction caused an error. IGNNE# has no effect when the NE bit in control register 0 is set.
IGNNE# is an asynchronous signal. However, to ensure recognition of this signal following an I/O
write instruction, it must be valid along with the TRDY# assertion of the corresponding I/O Write
bus transaction.
Datasheet
91
Pentium® III Xeon™ Processor at 500 and 550 MHz
During active RESET#, the Pentium III Xeon processor begins sampling the A20M#, IGNNE# ,
and LINT[1:0] values to determine the ratio of core-clock frequency to bus-clock frequency. See
Table 1. On the active-to-inactive transition of RESET#, the Pentium III Xeon processor latches
these signals and freezes the frequency ratio internally. System logic must then release these
signals for normal operation.
9.1.27
INIT# (I)
The INIT# (Initialization) signal, when asserted, resets integer registers inside all processors
without affecting their internal (L1 or L2) caches or floating-point registers. Each processor then
begins execution at the power-on reset vector configured during power-on configuration. The
processor continues to handle snoop requests during INIT# assertion. INIT# is an asynchronous
signal and must connect the appropriate pins of all Pentium III Xeon processor system bus agents.
If INIT# is sampled active on the active to inactive transition of RESET#, then the processor
executes its Built-In Self-Test (BIST).
9.1.28
INTR - see LINT0
9.1.29
LINT[1:0] (I)
The LINT[1:0] (Local APIC Interrupt) signals must connect the appropriate pins of all APIC Bus
agents, including all processors and the core logic or I/O APIC component. When the APIC is
disabled, the LINT0 signal becomes INTR, a maskable interrupt request signal, and LINT1
becomes NMI, a nonmaskable interrupt. INTR and NMI are backward compatible with the signals
of those names on the Pentium processor. Both signals are asynchronous.
Both of these signals must be software configured via BIOS programming of the APIC register
space to be used either as NMI/INTR or LINT[1:0]. Because the APIC is enabled by default after
reset, operation of these pins as LINT[1:0] is the default configuration.
During active RESET#, the Pentium III Xeon processor begins sampling the A20M#, IGNNE# ,
and LINT[1:0] values to determine the ratio of core-clock frequency to bus-clock frequency. See
Table 1. On the active-to-inactive transition of RESET#, the Pentium III Xeon processor samples
these signals and latches the frequency ratio internally. System logic must then release these signals
for normal operation.
9.1.30
LOCK# (I/O)
The LOCK# signal indicates to the system that a transaction must occur atomically. This signal
must connect the appropriate pins of all Pentium III Xeon processor system bus agents. For a
locked sequence of transactions, LOCK# is asserted from the beginning of the first transaction end
of the last transaction.
When the priority agent asserts BPRI# to arbitrate for ownership of the Pentium III Xeon processor
system bus, it will wait until it observes LOCK# deasserted. This enables symmetric agents to
retain ownership of the Pentium III Xeon processor system bus throughout the bus locked operation
and ensure the atomicity of lock.
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Pentium® III Xeon™ Processor at 500 and 550 MHz
9.1.31
L2_SENSE
The L2_SENSE pin is connected to the VCC_L2 power plane on the substrate.
9.1.32
NMI - See LINT1
9.1.33
PICCLK (I)
The PICCLK (APIC Clock) signal is an input clock to the processor and core logic or I/O APIC
which is required for operation of all processors, core logic, and I/O APIC components on the
APIC bus. During FRC mode operation, PICCLK must be 1/4 of (and synchronous to) BCLK.
9.1.34
PICD[1:0] (I/O)
The PICD[1:0] (APIC Data) signals are used for bi-directional serial message passing on the APIC
bus, and must connect the appropriate pins of all processors and core logic or I/O APIC
components on the APIC bus.
9.1.35
PM[1:0]# (O)
The PM[1:0]# (Performance Monitor) signals are outputs from the processor which indicate the
status of programmable counters used for monitoring processor performance.
9.1.36
PRDY# (O)
The PRDY (Probe Ready) signal is a processor output used by debug tools to determine processor
debug readiness. See Section 8.0 for more information on this signal.
9.1.37
PREQ# (I)
The PREQ# (Probe Request) signal is used by debug tools to request debug operation of the
processors. See Section 8.0 for more information on this signal.
9.1.38
PWREN[1:0] (I)
These 2 pins are tied directly together on the processor. They can be used to detect processor
presence by applying a voltage to one pin and observing it at the other. See Table 4 for the
maximum rating for this signal.
9.1.39
PWRGOOD (I)
The PWRGOOD (Power Good) signal is a 2. 5V tolerant processor input. The processor requires
this signal to be a clean indication that the clocks and power supplies (VCCCORE, VCCL2, VCCTAP ,
VCCSMBUS) are stable and within their specifications. Clean implies that the signal will remain low
(capable of sinking leakage current), without glitches, from the time that the power supplies are
turned on until they come within specification. The signal must then transition monotonically to a
high (2.5 V ) state.Figure 44 illustrates the relationship of PWRGOOD to other system signals.
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Pentium® III Xeon™ Processor at 500 and 550 MHz
PWRGOOD can be driven inactive at any time, but clocks and power must again be stable before a
subsequent rising edge of PWRGOOD. It must also meet the minimum pulse width specification in
Table 11 and be followed by a 1 m s RESET# pulse.
The PWRGOOD signal must be supplied to the processor; it is used to protect internal circuits
against voltage sequencing issues. The PWRGOOD signal does not need to be synchronized for
FRC operation. It should be driven high throughout boundary scan operation.
Figure 44. PWRGOOD Relationship at Power-On
BCLK
VCCCORE
VCC
L2
WRGOOD
1 ms
RESET#
Clock Ratio
9.1.40
REQ[4:0]# (I/O)
The REQ[4:0]# (Request Command) signals must connect the appropriate pins of all Pentium III
Xeon processor system bus agents. They are asserted by the current bus owner over two clock
cycles to define the currently active transaction type.
9.1.41
RESET# (I)
Asserting the RESET# signal resets all processors to known states and invalidates their L1 and L2
caches without writing back any of their contents. RESET# must remain active for one
microsecond for a “warm” reset; for a power-on reset, RESET# must stay active for at least one
millisecond after CCCORE and CLK have reached their proper specifications. On observing active
RESET#, all Pentium III Xeon processor system bus agents will deassert their outputs within two
clocks.
A number of bus signals are sampled at the active-to-inactive transition of RESET# for power-on
configuration. These configuration options are described in the Pentium® II Processor Developer’s
Manual.
The processor may have its outputs tri-stated via power-on configuration. Otherwise, if INIT# is
sampled active during the active-to-inactive transition of RESET#, the processor will execute its
Built-In Self-Test (BIST). Whether or not BIST is executed, the processor will begin program
execution at the reset-vector (default 0_FFFF_FFF0h). RESET# must connect the appropriate pins
of all Pentium III Xeon processor system bus agents.
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9.1.42
RP# (I/O)
The RP# (Request Parity) signal is driven by the request initiator, and provides parity protection on
ADS# and REQ[4:0]#. It must connect the appropriate pins of all Pentium III Xeon processor
system bus agents.
A correct parity signal is high if an even number of covered signals are low and low if an odd
number of covered signals are low. This definition allows parity to be high when all covered signals
are high.
9.1.43
RS[2:0]# (I)
The RS[2:0]# (Response Status) signals are driven by the response agent (the agent responsible for
completion of the current transaction), and must connect the appropriate pins of all Pentium III
Xeon processor system bus agents.
9.1.44
RSP# (I)
The RSP# (Response Parity) signal is driven by the response agent (the agent responsible for
completion of the current transaction) during assertion of RS[2:0]#, the signals for which RSP#
provides parity protection. It must connect the appropriate pins of all Pentium III Xeon processor
system bus agents.
A correct parity signal is high if an even number of covered signals are low and low if an odd
number of covered signals are low. While RS[2:0]# = 000, RSP# is also high, since this indicates it
is not being driven by any agent guaranteeing correct parity.
9.1.45
SA[2:0] (I)
The SA (Select Address) pins are decoded on the SMBus in conjunction with the upper address bits
in order to maintain unique addresses on the SMBus in a system with multiple Pentium III Xeon
processors. To set an SA line high, a pull-up resistor should be used that is no larger than 1 k Ω. To
set an SA line as low, SA1 and SA0 can be left unconnected; to set SA2 as low, it should be pulled
to ground (~10 kΩ). SA2 can also be tri-stated to define additional addresses for the thermal sensor.
A tri-state or “Z” state on this pin is achieved by leaving this pin unconnected.
Of the addresses broadcast across the SMBus, the memory components claim those of the form
“1010XXYZb”. The “XX” and “Y” bits are used to enable the devices on the cartridge at adjacent
addresses. The Y bit is hard-wired on the cartridge to VSS (‘0’) for the Scratch EEPROM and
pulled to VCCSMBUS (‘1’) for the Processor Information ROM. The “XX” bits are defined by the
processor slot via the SA0 and SA1 pins on the SC330 connector. These address pins are pulled
down weakly (10 kΩ) on the cartridge to ensure that the memory components are in a known state
in systems which do not support the SMBus, or only support a partial implementation. The “Z” bit
is the read/write bit for the serial bus transaction.
The thermal sensor internally decodes 1 of 3 upper address patterns from the bus of the form
“0011XXXZb”, “1001XXXZb” or “0101XXXZb”. The device’s addressing, as implemented,
includes a Hi-Z state for one address pin (SA2), and therefore supports 6 unique resulting
addresses. The ability of the system to drive this pin to a Hi-Z state is dependent on the baseboard
implementation (The pin must be left floating). The system should drive SA1 and SA0, and will be
pulled low (if not driven) by the 10k Ω pull-down resistor on the processor substrate. Driving these
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Pentium® III Xeon™ Processor at 500 and 550 MHz
signals to a Hi-Z state would cause ambiguity in the memory device address decode, possibly
resulting in the devices not responding, thus timing out or hanging the SMBus. As before, the “Z”
bit is the read/write bit for the serial bus transaction.
For more information on the usage of these pins, see Section 4.3.7.
9.1.46
SELFSB[1:0] (I/O)
Pentium III Xeon processors do not have a selectable system bus speed option. For Pentium III
Xeon processors SELFSB0 should be left as an open. For systems which only support a 1 0 0MHz
system bus SELFSB1 should be grounded or left open. For systems which are intended to support
current processors with a 100MHz system bus and future processors with a 1 3 3MHz system bus
SELFSB1 may be connected to the baseboard logic which selects betwe en 100MHz a nd 133MHz.
For Pentium III Xeon processors and future 1 0 0MHz only processors this signal will pulled to
ground via a ~330Ω resistor. Future processors that will support a 133MHz system bus will leave
SELFSB1 open.
9.1.47
SLP# (I)
The SLP# (Sleep) signal, when asserted in Stop Grant state, causes processors to enter the Sleep
state. During Sleep state, the processor stops providing internal clock signals to all units, leaving
only the Phase-Locked Loop (PLL) still operating. Processors in this state will not recognize
snoops or interrupts. The processor will recognize only assertions of the SLP#, STPCLK#, and
RESET# signals while in Sleep state. If SLP# is deasserted, the processor exits Sleep state and
returns to Stop Grant state, restarting its internal clock signals to the bus and APIC processor core
units.
9.1.48
SMBALERT# (O)
SMBALERT# is an asynchronous interrupt line associated with the SMBus Thermal Sensor
device.
9.1.49
SMBCLK (I)
The SMBCLK (SMBus Clock) signal is an input clock to the system management logic which is
required for operation of the system management features of the Pentium III Xeon processor. This
clock is asynchronous to other clocks to the processor.
9.1.50
SMBDAT (I/O)
The SMBDAT (SMBus DATa) signal is the data signal for the SMBus. This signal provides the
single-bit mechanism for transferring data between SMBus devices.
9.1.51
SMI# (I)
The SMI# (System Management Interrupt) signal is asserted asynchronously by system logic. On
accepting a System Management Interrupt, processors save the current state and enter System
Management Mode (SMM). An SMI Acknowledge transaction is issued, and the processor begins
program execution from the SMM handler.
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9.1.52
STPCLK# (I)
The STPCLK# (Stop Clock) signal, when asserted, causes processors to enter a low power Stop
Grant state. The processor issues a Stop Grant Acknowledge transaction, and stops providing
internal clock signals to all processor core units except the bus and APIC units. The processor
continues to snoop bus transactions and service interrupts while in Stop Grant state. When
STPCLK# is deasserted, the processor restarts its internal clock to all units and resumes execution.
The assertion of STPCLK# has no effect on the bus clock; STPCLK# is an asynchronous input.
9.1.53
TCK (I)
The TCK (Test Clock) signal provides the clock input for the Pentium III Xeon processor Test Bus
(also known as the Test Access Port).
9.1.54
TDI (I)
The TDI (Test Data In) signal transfers serial test data into the Pentium III Xeon processor. TDI
provides the serial input needed for TAP support.
9.1.55
TDO (O)
The TDO (Test Data Out) signal transfers serial test data out of the Pentium III Xeon processor.
TDO provides the serial output needed for TAP support.
9.1.56
TEST_25_A62 (I)
The TEST_25_A62 signal must be connected to a 2. 5V power source through a 1-10 kΩ resistor
for proper processor operation.
9.1.57
TEST_VCC_CORE_XXX (I)
The TEST_VCC_CORE_XXX signals must be connected separately to VCCCORE via ~10 kΩ
resistors.
9.1.58
THERMTRIP# (O)
This pin indicates a thermal overload condition (thermal trip). The processor protects itself from
catastrophic overheating by use of an internal thermal sensor. This sensor is set well above the
normal operating temperature to ensure that there are no false trips. The processor will immediately
stop all execution when the junction temperature exceeds approximately 135°C . This is signaled to
the system by the THERMTRIP# pin. Once activated, the signal remains latched, and the processor
stopped, until RESET# goes active. There is no hysteresis built into the thermal sensor itself. Once
the die temperature drops below the trip level, a RESET# pulse will reinitialize the processor and
execution will continue at the reset vector. If the temperature has not dropped below the trip level,
the processor will continue to drive THERMTRIP# and remain stopped regardless of the state of
RESET#.
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Pentium® III Xeon™ Processor at 500 and 550 MHz
9.1.59
TMS (I)
The TMS (Test Mode Select) signal is a TAP support signal used by debug tools.
9.1.60
TRDY# (I)
The TRDY# (Target Ready) signal is asserted by the target to indicate that it is ready to receive a
write or implicit writeback data transfer. TRDY# must connect the appropriate pins of all Pentium
III Xeon processor system bus agents.
9.1.61
TRST# (I)
The TRST# (Test Reset) signal resets the Test Access Port (TAP) logic. Pentium III Xeon
processors self-reset during power on; therefore, it is not necessary to drive this signal during
power on reset.
9.1.62
VID_L2[4:0], VID_CORE[4:0](O)
The VID (Voltage ID) pins can be used to support automatic selection of power supply voltages.
These pins are not signals, but are either an open circuit or a short circuit to VSS on the processor.
The combination of opens and shorts defines the voltage required by the processor. The VID pins
are needed to cleanly support voltage specification variations on Pentium III Xeon processors. See
Table 2 for definitions of these pins. The power supply must supply the voltage that is requested by
these pins, or disable itself. See Table 4 for the maximum rating for these signals.
9.1.63
WP (I)
WP (Write Protect) can be used to write protect the scratch EEPROM. A high level write-protects
the scratch EEPROM.
9.2
Signal Summaries
The following tables list attributes of the Pentium III Xeon processor output, input, and I/O signals.
Table 48. Output Signals †
†
98
Name
Active Level
Clock
Signal Group
FERR#
Low
Asynch
CMOS Output
IERR#
Low
Asynch
CMOS Output
PRDY#
Low
BCLK
AGTL+ Output
SMBALERT#
Low
Asynch
SMBus Output
TDO
High
TCK
TAP Output
THERMTRIP#
Low
Asynch
CMOS Output
VID_CORE[4:0]
High
Asynch
Power/Other
VID_L2[4:0]
High
Asynch
Power/Other
Outputs are not checked in FRC mode.
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Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 49. Input Signals 1
Name
Active Level
Clock
Signal Group
Qualified
A20M#
Low
Asynch
CMOS Input
Always 2
BPRI#
Low
BCLK
AGTL+ Input
Always
BR[3:1]#
Low
BCLK
AGTL+ Input
Always
BCLK
High
—
System Bus Clock
Always
DEFER#
Low
BCLK
AGTL+ Input
Always
FLUSH#
Low
Asynch
CMOS Input
Always 2
IGNNE#
Low
Asynch
CMOS Input
Always 2
INIT#
Low
Asynch
CMOS Input
Always 2
INTR
High
Asynch
CMOS Input
APIC disabled mod
LINT[1:0]
High
Asynch
CMOS Input
APIC enabled mode
NMI
High
Asynch
CMOS Input
APIC disabled mod
PICCLK
High
—
APIC Clock
Always
PREQ#
Low
Asynch
CMOS Input
Always
PWRGOOD
High
Asynch
CMOS Input
Always
RESET#
Low
BCLK
AGTL+ Input
Always
RS[2:0]#
Low
BCLK
AGTL+ Input
Always
Always
RSP#
Low
BCLK
AGTL+ Input
SA[2:0]
High
SMBCLK
Power/Other
SMBCLK#
High
—
SMBus Clock
Always
SLP#
Low
Asynch
CMOS Input
During Stop Grant state
SMI#
Low
Asynch
CMOS Input
STPCLK#
Low
Asynch
CMOS Input
TCK
High
—
TAP Clock
TDI
High
TCK
TAP Input
TMS
High
TCK
TAP Input
TRST#
Low
Asynch
TAP Input
TRDY#
Low
BCLK
AGTL+ Input
WP
High
Asynch
SMBus Input
NOTES
1. All asynchronous input signals except PWRGOOD must be synchronous in FRC.
2. Synchronous assertion with active TDRY# ensures synchronization.
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Pentium® III Xeon™ Processor at 500 and 550 MHz
Table 50. I/O Signals (Single Driver)
Name
Active Level
Cloc
Signal Group
Qualified
A[35:03]#
Low
BCLK
AGTL+ I/O
ADS#, ADS#+1
ADS#
Low
BCLK
AGTL+ I/O
Always
AGTL+ I/O
ADS#, ADS#+1
AP[1:0]#
Low
BCLK
SELFSB[1:0]
High
—
BR0#
Low
BCLK
AGTL+ I/O
Always
BP[3:2]#
Low
BCLK
AGTL+ I/O
Always
Power/Other
BPM[1:0]#
Low
BCLK
AGTL+ I/O
Always
D[63:00]#
Low
BCLK
AGTL+ I/O
DRDY#
DBSY#
Low
BCLK
AGTL+ I/O
Always
DEP[7:0]#
Low
BCLK
AGTL+ I/O
DRDY#
DRDY#
Low
BCLK
AGTL+ I/O
Always
FRCERR
High
BCLK
AGTL+ I/O
Always
LOCK#
Low
BCLK
AGTL+ I/O
Always
REQ[4:0]#
Low
BCLK
AGTL+ I/O
ADS#, ADS#+1
ADS#, ADS#+1
RP#
Low
BCLK
AGTL+ I/O
SMBDAT
High
SMBCLK
SMBus I/O
Table 51. I/O Signals (Multiple Driver)
100
Name
Active Level
Cloc
AERR#
Low
BCLK
AGTL+ I/O
BERR#
Low
BCLK
AGTL+ I/O
Always
BNR#
Low
BCLK
AGTL+ I/O
Always
BINIT#
Low
BCLK
AGTL+ I/O
Always
HIT#
Low
BCLK
AGTL+ I/O
Always
AGTL+ I/O
Always
APIC I/O
Always
HITM#
Low
BCLK
PICD[1:0]
High
PICCLK
Signal Group
Qualified
ADS#+3
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
1.0
1.1
1.2
Introduction.........................................................................................................................9
Terminology .......................................................................................................... 9
1.1.1 S.E.C. Cartridge Terminology................................................................ 10
References ......................................................................................................... 10
2.0
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
2.10
2.11
2.12
Electrical Specifications....................................................................................................11
The Pentium® III Xeon™ Processor System Bus and VREF ........................................ 11
Power and Ground Pins...................................................................................... 12
Decoupling Guidelines........................................................................................ 12
2.3.1 Pentium® III Xeon™ Processor VCCCOR ........................................................... 13
2.3.2 Level 2 Cache Decoupling..................................................................... 13
2.3.3 System Bus AGTL+ Decoupling ............................................................ 13
System Bus Clock and Processor Clocking........................................................ 13
2.4.1 Mixing Processors ................................................................................. 15
Voltage Identification .......................................................................................... 16
System Bus Unused Pins and Test Pins ............................................................ 17
System Bus Signal Groups................................................................................. 18
2.7.1 Asynchronous vs. Synchronous for System Bus Signals ...................... 19
Test Access Port (TAP) Connection ................................................................... 19
Maximum Ratings ............................................................................................... 20
Processor DC Specifications .............................................................................. 20
AGTL+ System Bus Specifications..................................................................... 24
System Bus AC Specifications ........................................................................... 25
3.0
3.1
3.2
3.3
Signal Quality ...................................................................................................................32
System Bus Clock Signal Quality Specifications ................................................ 33
AGTL+ Signal Quality Specifications.................................................................. 33
3.2.1 AGTL+ Ringback Tolerance Specifications ........................................... 34
3.2.2 AGTL+ Overshoot/Undershoot Guidelines ............................................ 34
Non-AGTL+ Signal Quality Specifications .......................................................... 35
3.3.1 2.5 V Tolerant Buffer Overshoot/Undershoot Guidelines ...................... 35
3.3.2 2.5 V Tolerant Buffer Ringback Specification ........................................ 35
3.3.3 2.5 V Tolerant Buffer Settling Limit Guideline........................................ 36
4.0
4.1
4.2
4.3
Processor Features ..........................................................................................................36
Functional Redundancy Checking Mode ............................................................ 36
Low Power States and Clock Control ................................................................. 37
4.2.1 Normal State— State 1.......................................................................... 37
4.2.2 Auto Halt Power Down State — State 2 ................................................ 37
4.2.3 Stop-Grant State — State 3................................................................... 38
4.2.4 Halt/Grant Snoop State — State 4......................................................... 39
4.2.5 Sleep State — State 5 ........................................................................... 39
4.2.6 Clock Control ......................................................................................... 39
System Management Bus (SMBus) Interface..................................................... 40
4.3.1 Processor Information ROM .................................................................. 41
4.3.2 Scratch EEPROM .................................................................................. 42
4.3.3 Processor Information ROM and Scratch EEPROM Supported SMBus Transactions43
4.3.4 Thermal Sensor ..................................................................................... 43
4.3.5 Thermal Sensor Supported SMBus Transactions ................................. 44
4.3.6 Thermal Sensor Registers ..................................................................... 46
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4.3.7
5.0
5.1
5.2
6.0
6.1
6.2
6.3
7.0
7.1
7.2
7.3
8.0
8.1
8.2
9.0
9.1
102
4.3.6.1 Thermal Reference Registers....................................................46
4.3.6.2 Thermal Limit Registers.............................................................46
4.3.6.3 Status Register ..........................................................................46
4.3.6.4 Configuration Register ...............................................................47
4.3.6.5 Conversion Rate Register..........................................................47
SMBus Device Addressing .....................................................................48
Thermal Specifications and Design Considerations.........................................................49
Thermal Specifications ........................................................................................50
5.1.1 Power Dissipation ...................................................................................50
5.1.2 Plate Flatness Specification ...................................................................51
Processor Thermal Analysis ................................................................................51
5.2.1 Thermal Solution Performance ...............................................................51
5.2.2 Thermal Plate to Heat Sink Interface Management Guide .....................52
5.2.3 Measurements for Thermal Specifications .............................................53
5.2.3.1 Thermal Plate Temperature Measurement................................53
5.2.3.2 Cover Temperature Measurement Guideline ............................54
Mechanical Specifications................................................................................................55
Weight .................................................................................................................60
Cartridge to Connector Mating Details ................................................................60
Pentium® III Xeon™ Processor Substrate Edge Finger Signal Listing................62
Boxed Processor Specifications.......................................................................................71
Introduction..........................................................................................................71
Mechanical Specifications ...................................................................................71
7.2.1 Boxed Processor Heatsink Dimensions..................................................73
7.2.2 Boxed Processor Heatsink Weight .........................................................73
7.2.3 Boxed Processor Retention Mechanism.................................................73
Thermal Specifications ........................................................................................74
7.3.1 Boxed Processor Cooling Requirements................................................74
7.3.2 Optional Auxiliary Fan Attachment .........................................................74
7.3.2.1 Clearance Recommendations for Auxiliary Fan ........................76
7.3.2.2 Fan Power Recommendations for Auxiliary Fan .......................77
7.3.2.3 Thermal Evaluation for Auxiliary Fan.........................................78
Integration Tools ..............................................................................................................78
In-Target Probe (ITP) for Pentium® III Xeon™ Processors .................................78
8.1.1 Primary Function ....................................................................................79
8.1.2 Debug Port Connector Description.........................................................79
8.1.3 Debug Port Signal Descriptions..............................................................80
8.1.4 Debug Port Signal Notes ........................................................................82
8.1.4.1 General Signal Quality Notes ....................................................83
8.1.4.2 Signal Note: DBRESET# ...........................................................83
8.1.4.3 Signal Note: TDO and TDI.........................................................83
8.1.4.4 Signal Note: TCK .......................................................................83
8.1.5 Using Boundary Scan to Communicate to the Processor.......................85
Integration Tool (Logic Analyzer) Considerations................................................86
Appendix ..........................................................................................................................86
Alphabetical Signals Reference...........................................................................86
9.1.1 A[35:03]# (I/O) ........................................................................................86
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Pentium® III Xeon™ Processor at 500 and 550 MHz
9.1.2
9.1.3
9.1.4
9.1.5
9.1.6
9.1.7
9.1.8
9.1.9
9.1.10
9.1.11
9.1.12
9.1.13
9.1.14
9.1.15
9.1.16
9.1.17
9.1.18
9.1.19
9.1.20
9.1.21
9.1.22
9.1.23
9.1.24
9.1.25
9.1.26
9.1.27
9.1.28
9.1.29
9.1.30
9.1.31
9.1.32
9.1.33
9.1.34
9.1.35
9.1.36
9.1.37
9.1.38
9.1.39
9.1.40
9.1.41
9.1.42
9.1.43
9.1.44
9.1.45
9.1.46
9.1.47
9.1.48
9.1.49
9.1.50
9.1.51
Datasheet
A20M# (I) ............................................................................................... 86
ADS# (I/O) ............................................................................................. 87
AERR# (I/O)........................................................................................... 87
AP[1:0]# (I/O)......................................................................................... 87
BCLK (I) ................................................................................................. 87
BERR# (I/O)........................................................................................... 87
BINIT# (I/O) ........................................................................................... 88
BNR# (I/O) ............................................................................................. 88
BP[3:2]# (I/O)......................................................................................... 88
BPM[1:0]# (I/O) ...................................................................................... 88
BPRI# (I) ................................................................................................ 88
BR0# (I/O), BR[3:1]# (I) ......................................................................... 88
CPU_SENSE ......................................................................................... 89
D[63:00]# (I/O) ....................................................................................... 89
DBSY# (I/O)........................................................................................... 90
DEFER# (I) ............................................................................................ 90
DEP[7:0]# (I/O) ...................................................................................... 90
DRDY# (I/O) .......................................................................................... 90
EMI ........................................................................................................ 90
FERR# (O)............................................................................................. 90
FLUSH# (I)............................................................................................. 90
FRCERR (I/O)........................................................................................ 91
HIT# (I/O), HITM# (I/O).......................................................................... 91
IERR# (O) .............................................................................................. 91
IGNNE# (I) ............................................................................................. 91
INIT# (I).................................................................................................. 92
INTR - see LINT0................................................................................... 92
LINT[1:0] (I)............................................................................................ 92
LOCK# (I/O)........................................................................................... 92
L2_SENSE............................................................................................. 93
NMI - See LINT1.................................................................................... 93
PICCLK (I) ............................................................................................. 93
PICD[1:0] (I/O) ....................................................................................... 93
PM[1:0]# (O) .......................................................................................... 93
PRDY# (O)............................................................................................. 93
PREQ# (I) .............................................................................................. 93
PWREN[1:0] (I) ...................................................................................... 93
PWRGOOD (I) ....................................................................................... 93
REQ[4:0]# (I/O)...................................................................................... 94
RESET# (I) ............................................................................................ 94
RP# (I/O)................................................................................................ 95
RS[2:0]# (I) ............................................................................................ 95
RSP# (I) ................................................................................................. 95
SA[2:0] (I)............................................................................................... 95
SELFSB[1:0] (I/O).................................................................................. 96
SLP# (I).................................................................................................. 96
SMBALERT# (O) ................................................................................... 96
SMBCLK (I)............................................................................................ 96
SMBDAT (I/O)........................................................................................ 96
SMI# (I) .................................................................................................. 96
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9.1.52 STPCLK# (I) ...........................................................................................97
9.1.53 TCK (I) ....................................................................................................97
9.1.54 TDI (I) .....................................................................................................97
9.1.55 TDO (O) ..................................................................................................97
9.1.56 TEST_25_A62 (I)....................................................................................97
9.1.57 TEST_VCC_CORE_XXX (I) ...................................................................97
9.1.58 THERMTRIP# (O) ..................................................................................97
9.1.59 TMS (I)....................................................................................................98
9.1.60 TRDY# (I) ...............................................................................................98
9.1.61 TRST# (I)................................................................................................98
9.1.62 VID_L2[4:0], VID_CORE[4:0](O) ............................................................98
9.1.63 WP (I) .....................................................................................................98
Signal Summaries ...............................................................................................98
Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
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Timing Diagram of Clock Ratio Signals .............................................................. 15
Logical Schematic for Clock Ratio Pin Sharing .................................................. 15
I-V Curve for nMOS Device ................................................................................ 23
BCLK, PICCLK, TCK Generic Clock Waveform ................................................. 29
SMBCLK Clock Waveform.................................................................................. 29
Valid Delay Timings............................................................................................ 29
Setup and Hold Timings ..................................................................................... 30
FRC Mode BCLK to PICCLK Timing .................................................................. 30
System Bus Reset and Configuration Timings ................................................... 31
Power-On Reset and Configuration Timings ...................................................... 31
Test Timings (Boundary Scan) ........................................................................... 32
Test Reset Timings............................................................................................. 32
BCLK, TCK, PICCLK Generic Clock Waveform at the Processor Core Pins ..... 33
Low to High AGTL+ Receiver Ringback Tolerance ............................................ 34
Non-AGTL+ Overshoot/Undershoot, Settling Limit, and Ringback..................... 35
Stop Clock State Machine .................................................................................. 38
Logical Schematic of SMBus Circuitry................................................................ 40
Thermal Plate View............................................................................................. 50
Plate Flatness Reference ................................................................................... 51
Interface Agent Dispensing Areas and Thermal Plate Temperature Measurement Points53
Technique for Measuring TPLATE with 0° Angle Attachment .............................. 54
Technique for Measuring TPLATE with 90° Angle Attachment ............................ 54
Guideline Locations for Cover Temperature (TCOVER) Thermocouple Placement55
Isometric View of Pentium® III Xeon™ Processor S.E.C. Cartridge................... 56
S.E.C. Cartridge Cooling Solution Attach Details (Notes follow Figure 27) ........ 57
S.E.C. Cartridge Retention Enabling Details (Notes follow Figure 27) ............... 58
S.E.C. Cartridge Retention Enabling Details ...................................................... 59
Side View of Connector Mating Details .............................................................. 60
Top View of Cartridge Insertion Pressure Points................................................ 61
Front View of Connector Mating Details ............................................................. 61
Boxed Pentium® III Xeon™ Processor ............................................................... 71
Side View Space Requirements for the Boxed Processor.................................. 72
Front View Space Requirements for the Boxed Processor ................................ 73
Front Views of the Boxed Processor with Attached Auxiliary Fan (Not Included with Boxed Processor)75
Front View of Boxed Processor Heatsink with Fan Attach Features (Fan Not Included)75
Cross-sectional View of Grommet Attach Features in the Heatsink (Grommet Shown)76
Side View Space Recommendation for the Auxiliary Fan .................................. 76
Front View Space Recommendations for the Auxiliary Fan ............................... 77
Boxed Processor Fan/Heatsink Power Cable Connector Description ................ 77
Hardware Components of an ITP ....................................................................... 79
AGTL+ Signal Termination ................................................................................. 82
TCK with Individual Buffering Scheme ............................................................... 84
System Preferred Debug Port Layout................................................................. 85
PWRGOOD Relationship at Power-On .............................................................. 94
Datasheet
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Datasheet
Pentium® III Xeon™ Processor at 500 and 550 MHz
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Core Frequency to System Bus Multiplier Configuration.................................... 14
Core and L2 Voltage Identification Definition 1, 2...................................................................16
Pentium® III Xeon™ Processor System Bus Pin Groups ................................... 18
Pentium® III Xeon™ Processor Absolute Maximum Ratings.............................. 20
Voltage Specifications 1 .....................................................................................................................21
Current Specifications 1......................................................................................................................22
AGTL+ Signal Groups, DC Specifications at the Processor Core ...................... 23
CMOS, TAP, Clock and APIC Signal Groups, DC Specifications at the Processor Core24
SMBus Signal Group, DC Specifications at the Processor Core........................ 24
Pentium® III Xeon™ Processor Internal Parameters for the AGTL+ Bus ........... 25
System Bus AC Specifications (Clock) at the Processor Core ........................... 25
AGTL+ Signal Groups, System Bus AC Specifications at the Processor Core 1 ..26
CMOS, TAP, Clock and APIC Signal Groups, AC Specifications at the Processor Core 1, 226
System Bus AC Specifications (Reset Conditions)............................................. 27
System Bus AC Specifications (APIC Clock and APIC I/O) at the Processor Core 127
System Bus AC Specifications (TAP Connection) at the Processor Core 1 ............28
SMBus Signal Group, AC Specifications at the Edge Fingers............................ 28
BCLK Signal Quality Specifications for Simulation at the Processor Core 1 ...........33
AGTL+ Signal Groups Ringback Tolerance Specifications at the Processor Core 1, 2, 334
AGTL+ Overshoot/Undershoot Guidelines at the Processor Core ..................... 35
2.5 V Tolerant Signal Overshoot/Undershoot Guidelines at the Processor Core 35
Signal Ringback Specifications for 2 .5V Tolerant Signal Simulation at the Processor Core36
Processor Information ROM Format................................................................... 41
Current Address Read SMBus Packet ............................................................... 43
Random Address Read SMBus Packet.............................................................. 43
Byte Write SMBus Packet................................................................................... 43
Write Byte SMBus Packet................................................................................... 45
Read Byte SMBus Packet .................................................................................. 45
Send Byte SMBus Packet................................................................................... 45
Receive Byte SMBus Packet .............................................................................. 45
ARA SMBus Packet............................................................................................ 45
Command Byte Bit Assignments ........................................................................ 45
Thermal Sensor Status Register......................................................................... 47
Thermal Sensor Configuration Register ............................................................. 47
Thermal Sensor Conversion Rate Register ........................................................ 48
Thermal Sensor SMBus Addressing on the Pentium® III Xeon™ Processor ..... 49
Memory Device SMBus Addressing on the Pentium® III Xeon™ Processor...... 49
Thermal Design Power 1....................................................................................................................51
Example Thermal Solution Performance at Thermal Plate Power of 50 Watts .. 52
Signal Listing in Order by Pin Number................................................................ 62
Signal Listing in Order by Pin Name................................................................... 66
Boxed Processor Heatsink Dimensions.............................................................. 73
Fan/Heatsink Power and Signal Specifications .................................................. 78
Debug Port Pinout Description and Requirements 1 ...........................................................80
BR[3:0]# Signals Rotating Interconnect, 4-Way System .................................... 89
BR[3:0]# Signals Rotating Interconnect, 2-Way System .................................... 89
Agent ID Configuration ....................................................................................... 89
Output Signals † .....................................................................................................................................98
Input Signals 1.........................................................................................................................................99
I/O Signals (Single Driver) ................................................................................ 100
Datasheet
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I/O Signals (Multiple Driver)...............................................................................100
Datasheet
UNITED STATES, Intel Corporation
2200 Mission College Blvd., P.O. Box 58119, Santa Clara, CA 95052-8119
Tel: +1 408 765-8080
JAPAN, Intel Japan K.K.
5-6 Tokodai, Tsukuba-shi, Ibaraki-ken 300-26
Tel: + 81-29847-8522
FRANCE, Intel Corporation S.A.R.L.
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UNITED KINGDOM, Intel Corporation (U.K.) Ltd.
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Tel: +44 1-793-641440
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Tel: +49 89/99143-0
HONG KONG, Intel Semiconductor Ltd.
32/F Two Pacific Place, 88 Queensway, Central
Tel: +852 2844-4555
CANADA, Intel Semiconductor of Canada, Ltd.
190 Attwell Drive, Suite 500
Rexdale, Ontario M9W 6H8
Tel: +416 675-2438
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Centro Empresarial Nações Unidas - Edifício Torre Oeste
Av. das Nações Unidas, 12.901 - 18o. andar - Brooklin Novo
04578.000 São Paulo - S.P. – Brasil
Tel: +55-11-5505-2296