2 Technical Reference
2.1 Memory Resources
2.1.1 Addressable Memory
The board utilizes 16 GB of addressable system memory. Typically the address space that is allocated for PCI Conventional bus add-in cards, PCI Express configuration space, BIOS (SPI Flash device), and chipset overhead resides above the top of DRAM
(total system memory). On a system that has 16 GB of system memory installed, it is not possible to use all of the installed memory due to system address space being allocated for other system critical functions. These functions include the following:
• BIOS/SPI Flash device (64 Mbit)
• Local APIC (19 MB)
• Direct Media Interface (40 MB)
• Front side bus interrupts (17 MB)
• PCI Express configuration space (256 MB)
• PCH base address registers PCI Express ports (up to 256 MB)
• Memory-mapped I/O that is dynamically allocated for PCI Conventional and PCI
Express add-in cards (256 MB)
The board provides the capability to reclaim the physical memory overlapped by the memory mapped I/O logical address space. The board remaps physical memory from the top of usable DRAM boundary to the 4 GB boundary to an equivalent sized logical
address range located just above the 4 GB boundary. Figure 8 shows a schematic of
the system memory map. All installed system memory can be used when there is no overlap of system addresses.
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Intel Desktop Board DH55TC Technical Product Specification
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Figure 8. Detailed System Memory Address Map
Technical Reference
2.1.2 Memory Map
Table 8 lists the system memory map.
Table 8. System Memory Map
Address Range (decimal) Address Range (hex)
1024 K - 16777216 K 100000 - 3FFFFFFFF
960 K - 1024 K F0000 - FFFFF
896 K - 960 K
800 K - 896 K
E0000 - EFFFF
C8000 - DFFFF
640 K - 800 K
639 K - 640 K
A0000 - C7FFF
9FC00 - 9FFFF
512 K - 639 K
0 K - 512 K
80000 - 9FBFF
00000 - 7FFFF
2.2 Connectors and Headers
Size Description
16382 MB Extended memory
64 KB Runtime BIOS
64 KB
96 KB
160 KB
1 KB
127 KB
512 KB
Reserved
Potential available high DOS memory (open to the PCI
Conventional bus). Dependent on video adapter used.
Video memory and BIOS
Extended BIOS data (movable by memory manager software)
Extended conventional memory
Conventional memory
CAUTION
Only the following connectors and headers have overcurrent protection: back panel and front panel USB and PS/2.
The other internal connectors and headers are not overcurrent protected and should connect only to devices inside the computer’s chassis, such as fans and internal peripherals. Do not use these connectors or headers to power devices external to the computer’s chassis. A fault in the load presented by the external devices could cause damage to the computer, the power cable, and the external devices themselves.
Furthermore, improper connection of USB header single wire connectors may eventually overload the overcurrent protection and cause damage to the board.
This section describes the board’s connectors. The connectors can be divided into these groups:
• Back panel I/O connectors
• Component-side I/O connectors and headers (see page 39)
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Intel Desktop Board DH55TC Technical Product Specification
2.2.1 Back Panel Connectors
Figure 9 shows the location of the back panel connectors for the board.
Item Description
A PS/2 keyboard/mouse port
G LAN
I
J
Audio line in
Audio line out
Figure 9. Back Panel Connectors
NOTE
The back panel audio line out connector is designed to power headphones or amplified speakers only. Poor audio quality occurs if passive (non-amplified) speakers are connected to this output.
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Technical Reference
2.2.2 Component-side Connectors and Headers
Figure 10 shows the locations of the component-side connectors and headers.
Figure 10. Component-side Connectors and Headers
Table 9 lists the component-side connectors and headers identified in Figure 10.
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Intel Desktop Board DH55TC Technical Product Specification
N
O
P
K
L
M
Table 9. Component-side Connectors and Headers Shown in Figure 10
F
G
H
I
C
D
E
Item/callout
from Figure 10
A
B
Description
PCI Conventional bus add-in card connector
PCI Express x1 bus add-in card connector
PCI Express x1 bus add-in card connector
PCI Express x16 bus add-in card connector
12 V internal power connector (ATX12V)
Rear chassis fan header
Processor fan header
Front chassis fan header
Main power connector (2 x 12)
Alternate front panel power LED header
Front panel header
USB header with support for an Intel Z-U130 USB Solid-State Drive (or compatible device)
USB headers (2)
Parallel port header
Serial port header
R
S
Front panel audio header
Internal mono speaker header
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Technical Reference
2.2.2.1 Signal Tables for the Connectors and Headers
Table 10. Serial Port Header
Pin Signal Name
1
3
5
7
9
DCD (Data Carrier Detect)
TXD# (Transmit Data)
Ground
RTS (Request To Send)
RI (Ring Indicator)
Pin
2
4
6
8
10
Signal Name
RXD# (Receive Data)
DTR (Data Terminal Ready)
DSR (Data Set Ready)
CTS (Clear To Send)
Key (no pin)
Table 11. Parallel Port Header
Pin Standard Signal Name ECP Signal Name EPP Signal Name
DATASTB# 2 AUTOFD#
4 FAULT#
6 INT#
21 BUSY
23 PERROR
26 KEY (no pin) KEY (no pin)
WAIT#
PE
KEY (no pin)
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Intel Desktop Board DH55TC Technical Product Specification
Table 12. S/PDIF Header
1 Ground
3 Key (no pin)
3 +5V_DC
Table 13. Internal Mono Speaker Header
1 −
2 +
Table 14. Front Panel Audio Header for Intel HD Audio
Pin
1
3
5
7
9
Signal Name
[Port 1] Left channel
[Port 1] Right channel
[Port 2] Right channel
SENSE_SEND (Jack detection)
[Port 2] Left channel
Pin
2
4
6
8
10
Signal Name
Ground
PRESENCE# (HD Audio/AC ’97 detect)
[Port 1] SENSE_RETURN
Key (no pin)
[Port 2] SENSE_RETURN
Table 15. Front Panel Audio Header for Passive AC ’97 Audio
1 MIC
3 MIC_BIAS
5 FP_OUT_R
7 NC (no connect)
9 FP_OUT_L
2 AUD_GND
6 AUD_GND
8 KEY (no pin)
Table 16. Front Panel USB Header
1 +5 VDC
3 D-
5 D+
7 Ground
9 KEY (no pin)
2 +5 VDC
4 D-
6 D+
8 Ground
10 No Connect
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Technical Reference
Table 17. Front Panel USB Header (with Intel Z-U130 USB Solid-State Drive, or Compatible Device, Support)
1 +5 VDC
5 D+
7 Ground
9 KEY (no pin)
Table 18. SATA Connectors
2 +5 VDC
6 D+
8 Ground
10 LED#
1 Ground
2 TXP
3 TXN
4 Ground
5 RXN
6 RXP
7 Ground
Table 19. Processor (4-Pin) Fan Header
1 Ground
3 FAN_TACH
4 FAN_CONTROL
Table 20. Front and Rear Chassis Fan Headers
1 Ground
3 FAN_TACH
4 FAN_CONTROL
3 Ground
2 FAN_POWER
1 FAN_TACH
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Intel Desktop Board DH55TC Technical Product Specification
2.2.2.2 Add-in Card Connectors
The board has the following add-in card connectors:
• One PCI Express 2.0 x16: this connector supports simultaneous transfer speeds of up to 8 GB/s of peak bandwidth per direction.
• Two PCI Express 2.0 x1: each of these connectors support simultaneous transfer speeds of up to 500 MB/s of peak bandwidth per direction.
• One Conventional PCI (rev 2.3 compliant) connector.
Note the following considerations for the Conventional PCI bus connector:
• The Conventional PCI bus connector is bus master capable.
• SMBus signals are routed to the Conventional PCI bus connector. This enables
Conventional PCI bus add-in boards with SMBus support to access sensor data on the desktop board. The specific SMBus signals are as follows:
⎯ The SMBus clock line is connected to pin A40.
⎯ The SMBus data line is connected to pin A41.
2.2.2.3 Power Supply Connectors
The board has the following power supply connectors:
• Main power – a 2 x 12 connector. This connector is compatible with 2 x 10 connectors previously used on Intel Desktop boards. The board supports the use of ATX12V power supplies with either 2 x 10 or 2 x 12 main power cables. When using a power supply with a 2 x 10 main power cable, pins 11, 12, 23, and
24 must remain unconnected.
• Processor core power – a 2 x 2 connector. This connector provides power directly to the processor voltage regulator and must always be used. Failure to do so will prevent the board from booting.
CAUTION
If a high power (75 W or greater) add-in card is installed in the PCI Express x16 connector, that card must also be connected directly to the power supply. Failure to do so may cause damage to the board and the add-in card.
Table 21. Processor Core Power Connector
1 Ground 2 Ground
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Technical Reference
Table 22. Main Power Connector
1 +3.3 V
3 Ground
4 +5 V
5 Ground
13
16
+3.3 V
PS-ON# (power supply remote on/off)
7 Ground
8 PWRGD (Power Good)
9 +5 V (Standby)
20
21
−5 V (obsolete)
+5 V
12
V 23
+3.3 V 2 x 12 connector detect
(Note)
24 Ground
Note: When using a 2 x 10 power supply cable, this pin will be unconnected.
For information about
Power supply considerations
Refer to
Section 2.5.1 on page 52
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Intel Desktop Board DH55TC Technical Product Specification
2.2.2.4 Front Panel Header
This section describes the functions of the front panel header. Table 23 lists the signal names of the front panel header. Figure 11 is a connection diagram for the front panel
header.
Table 23. Front Panel Header
Pin Signal
In/
Out Description Pin Signal
Hard Drive Activity LED
1
3
HD_PWR
HDA#
Out
Out
Hard disk LED pull-up to +5 V
Hard disk active
LED
Power LED
2 FP_LED+
4 FP_LED−
Reset Switch On/Off Switch
5 Ground Ground 6 PWR#
In Reset 8 Ground
In/
Out Description
Out
Out
Front panel green
LED
Front panel yellow
LED
Ground
Figure 11. Connection Diagram for Front Panel Header
2.2.2.4.1 Hard Drive Activity LED Header
Pins 1 and 3 can be connected to an LED to provide a visual indicator that data is being read from or written to an internal storage device. Proper LED function requires a SATA hard drive or optical drive connected to an onboard SATA connector, or the use of an Intel Z-U130 Solid-State Drive (or compatible device).
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Technical Reference
2.2.2.4.2 Reset Switch Header
Pins 5 and 7 can be connected to a momentary single pole, single throw (SPST) type switch that is normally open. When the switch is closed, the board resets and runs the
POST.
2.2.2.4.3 Power LED Header
Pins 2 and 4 can be connected to a one- or two-color LED. Table 24 shows the default
states for this LED. More options are available through BIOS setup.
Table 24. States for a One-Color Power LED
LED State Description
Steady Lit Running
Blink Standby
2.2.2.4.4 Power Switch Header
Pins 6 and 8 can be connected to a front panel momentary-contact power switch. The switch must pull the SW_ON# pin to ground for at least 50 ms to signal the power supply to switch on or off. (The time requirement is due to internal debounce circuitry on the board.) At least two seconds must pass before the power supply will recognize another on/off signal.
2.2.2.5 Auxiliary Front Panel Power LED Header
Pins 1 and 3 of this header duplicate the signals on pins 2 and 4 of the front panel header.
Table 25. Auxiliary Front Panel Power LED Header
1 FP_LED+
In/Out
Out
Description
FP_LED+
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Intel Desktop Board DH55TC Technical Product Specification
2.2.2.6 Front Panel USB Headers
Figure 12 is a connection diagram for the front panel USB headers.
NOTE
• The +5 V DC power on the USB headers is fused.
• Use only a front panel USB connector that conforms to the USB 2.0 specification
for high-speed USB devices.
Figure 12. Connection Diagram for Front Panel USB Headers
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Figure 13. Connection Diagram for Front Panel USB Header
(with Intel Z-U130 USB Solid-State Drive, or Compatible Device, Support)
Technical Reference
2.3 Jumper Block
CAUTION
Do not move the jumper with the power on. Always turn off the power and unplug the power cord from the computer before changing a jumper setting. Otherwise, the board could be damaged.
Figure 14 shows the location of the jumper block. The 3-pin jumper block determines
the BIOS Setup program’s mode. Table 26 describes the jumper settings for the three
modes: normal, configure, and recovery.
Figure 14. Location of the Jumper Block
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Intel Desktop Board DH55TC Technical Product Specification
Table 26. BIOS Setup Configuration Jumper Settings
Normal 1-2 The BIOS uses current configuration information and passwords for booting.
Configure 2-3
Recovery None
After the POST runs, Setup runs automatically. The maintenance menu is displayed.
Note that this Configure mode is the only way to clear the
BIOS/CMOS settings. Press F9 (restore defaults) while in
Configure mode to restore the BIOS/CMOS settings to their default values.
The BIOS attempts to recover the BIOS configuration. A recovery CD or USB flash drive is required.
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Technical Reference
2.4 Mechanical Considerations
2.4.1 Form Factor
The board is designed to fit into a MicroATX form-factor chassis. Figure 15 illustrates
the mechanical form factor for the board. Dimensions are given in inches
[millimeters]. The outer dimensions are 9.60 inches by 9.60 inches
[243.84 millimeters by 243.84 millimeters]. Location of the I/O connectors and mounting holes are in compliance with the ATX specification.
Figure 15. Board Dimensions
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Intel Desktop Board DH55TC Technical Product Specification
2.5 Electrical Considerations
2.5.1 Power Supply Considerations
CAUTION
The +5 V standby line from the power supply must be capable of providing adequate
+5 V standby current. Failure to do so can damage the power supply. The total amount of standby current required depends on the wake devices supported and manufacturing options.
Additional power required will depend on configurations chosen by the integrator.
The power supply must comply with the indicated parameters of the ATX form factor specification.
• The potential relation between 3.3 VDC and +5 VDC power rails
• The current capability of the +5 VSB line
• All timing parameters
• All voltage tolerances
For example, for a typical system configuration of a 95 W processor (see Section 1.4 on page 14 for information on supported processors), up to 16 GB DDR3 memory,
integrated graphics, one hard disk drive, one optical drive, and all board peripherals enabled, the minimum recommended power supply is about 320 W with current
ratings as listed in Table 27.
Table 27. Minimum Recommended Power Supply Current Values
Output Voltage
Current
3.3 V
5 A
5 V
12 A
+12 V1 +12 V2
10 A 10 A
-12 V
0.1 A
5 VSB
0.5 A
NOTE
+12 V1 denotes the 12 V rail at the 2 x 12 power header
+12 V2 denotes the 12 V rail at the 2 x 2 power header
For information about
Selecting an appropriate power supply
Refer to
http://www.intel.com/support/motherboards/desktop/sb/C
S-026472.htm
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Technical Reference
2.5.2 Fan Header Current Capability
CAUTION
The processor fan must be connected to the processor fan header, not to a chassis fan header. Connecting the processor fan to a chassis fan header may result in onboard component damage that will halt fan operation.
Table 28 lists the current capability of the fan headers.
Table 28. Fan Header Current Capability
Fan Header
Processor fan
Front chassis fan
Rear chassis fan
Maximum Available Current
2.0 A
1.5 A
1.5 A
2.5.3 Add-in Board Considerations
The board is designed to provide 2 A (average) of current for each add-in board from the +5 V rail. The total +5 V current draw for add-in boards for a fully loaded board
(all expansion slots filled) must not exceed the system’s power supply +5 V maximum current.
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Intel Desktop Board DH55TC Technical Product Specification
2.6 Thermal Considerations
CAUTION
Use of a processor heat sink that provides omni-directional airflow to maintain required airflow across the processor voltage regulator area is highly recommended.
CAUTION
Failure to ensure appropriate airflow may result in reduced performance of both the processor and/or voltage regulator or, in some instances, damage to the board. For a list of chassis that have been tested with Intel desktop boards please refer to the following website: http://www3.intel.com/cd/channel/reseller/asmo-na/eng/tech_reference/53211.htm
All responsibility for determining the adequacy of any thermal or system design remains solely with the reader. Intel makes no warranties or representations that merely following the instructions presented in this document will result in a system
with adequate thermal performance.
CAUTION
The ambient temperature must not exceed the board’s maximum operating temperature. Failure to do so could cause components to exceed their maximum case temperature and malfunction. For information about the maximum operating
temperature, see the environmental specifications in Section 2.8.
CAUTION
Ensure that proper airflow is maintained in the processor voltage regulator circuit.
Failure to do so may result in damage to the voltage regulator circuit.
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Technical Reference
Figure 16 shows the locations of the localized high temperature zones.
Item Description
A Processor voltage regulator area
B Processor
C Intel H55 Express Chipset
Figure 16. Localized High Temperature Zones
Table 29 provides maximum case temperatures for the components that are sensitive
to thermal changes. The operating temperature, current load, or operating frequency could affect case temperatures. Maximum case temperatures are important when considering proper airflow to cool the board.
Table 29. Thermal Considerations for Components
Component
Processor
Intel H55 Express Chipset
Maximum Case Temperature
For processor case temperature, see processor datasheets and processor specification updates
111 o C
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Intel Desktop Board DH55TC Technical Product Specification
To ensure functionality and reliability, the component is specified for proper operation when Case Temperature is maintained at or below the maximum temperature listed in
Table 29. This is a requirement for sustained power dissipation equal to Thermal
Design Power (TDP is specified as the maximum sustainable power to be dissipated by the components). When the component is dissipating less than TDP, the case temperature should be below the Maximum Case Temperature. The surface temperature at the geometric center of the component corresponds to Case
Temperature.
It is important to note that the temperature measurement in the system BIOS is a value reported by embedded thermal sensors in the components and does not directly correspond to the Maximum Case Temperature. The upper operating limit when
monitoring this thermal sensor is Tcontrol, as shown in Table 30.
Table 30. Tcontrol Values for Components
Component
Processor
Intel H55 Express Chipset
Tcontrol
For processor case temperature, see processor datasheets and processor specification updates
107 o
C
For information about
Processor datasheets and specification updates
Refer to
Section 1.3, page 14
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Technical Reference
2.7 Reliability
The Mean Time Between Failures (MTBF) prediction is calculated using component and subassembly random failure rates. The calculation is based on the Bellcore Reliability
Prediction Procedure, TR-NWT-000332, Issue 4, September 1991. The MTBF prediction is used to estimate repair rates and spare parts requirements.
The MTBF data is calculated from predicted data at 50 ºC. The MTBF for the board is
146,986 hours.
2.8 Environmental
Table 31 lists the environmental specifications for the board.
Table 31. Environmental Specifications
Parameter Specification
Temperature
Non-Operating -40 °C to +60 °C
Operating
Shock
0 °C to +40 °C
Unpackaged
Packaged
50 g trapezoidal waveform
Velocity change of 170 inches/second²
Half sine 2 millisecond
Product Weight (pounds) Free Fall (inches) Velocity Change (inches/sec²)
Vibration
Unpackaged
Packaged
5 Hz to 20 Hz: 0.01 g² Hz sloping up to 0.02 g² Hz
20 Hz to 500 Hz: 0.02 g² Hz (flat)
5 Hz to 40 Hz: 0.015 g² Hz (flat)
40 Hz to 500 Hz: 0.015 g² Hz sloping down to 0.00015 g² Hz
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Intel Desktop Board DH55TC Technical Product Specification
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