Intel Xeon User Manual

Schematic Checklist
194 Design Guide
Hub Interface A
HI[11:0] • Maximum length of 20" (stripline routing). • Refer to Section 7.3.1.
HI_STBF
11
HI_STBS
11
• Connect to ICH3-S.
• Must NOT have pull-up, pull-down, or series
resistors.
• Refer to Section 7.3.1.
Hub Interface B, C, D
HI[18:0]
HI[21:20]
• Maximum length of 20" (stripline routing). • Refer to Section 7.2.1.
PSTRBF
PSTRBS
PUSTRBF
PUSTRBS
• Connect to P64H2.
•Must
not have pull-up, pull-down, or series
resistors.
• Refer to Section 7.2.
Clocks, Reset, Miscellaneous Signals
HCLKINP
HLCKINN
• Route with a 49.9 Ω ± 1% pull-down resistor to
ground.
• Refer to Section 4.1.1.
CLK66 • Place 43
Ω series resistor close to CK408B. • Refer to Section 4.1.2.
RSTIN# • Connect to PCIRST# output of the ICH3-S.
Miscellaneous Signals
XORMODE# • 4.7 kΩ ± 5% pull-up to VCC_3.3. • Required for normal
operation.
Reserved
(Ball B30)
•4.7 k
Ω ± 5% pull-up to VCC_3.3. • Required for normal
operation.
Reserved
(Ball D29)
•1 k
Ω ± 5% pull-down to Ground. • Required for normal
operation.
HIRCOMP_A • Tie the MCH RCOMP pin to a 24.9
Ω ± 1% pull-
up to VCC_1.2
• (For Trace Impedance = 50
Ω ± 10%).
• Used to calibrate the I/O
Buffers.
• Resistive compensation is
used by the ICH3-S and MCH
to adjust the buffer
characteristics to specific
board characteristic.
• Refer to Section 7.3.3.
HIRCOMP_B
HIRCOMP_C
HIRCOMP_D
• Tie the MCH RCOMP pins to a 24.9
Ω ± 1%
pull-up to VCC_1.2
(For trace impedance = 50
Ω ± 10%).
• Tie the P64H2 RCOMP pins to a 61.9
Ω ± 1%
pull-up to VCC_1.8
(For trace impedance = 50
Ω ± 10%).
• Used to calibrate the I/O
Buffers.
• Resistive compensation is
used by the P64H2 and MCH
to adjust the buffer
characteristics to specific
board characteristics.
• Refer to Section 7.2.3.
HXRCOMP
HYRCOMP
• Tie each COMP pin to a 25
Ω ± 1% pull-down
resistor to ground.
• This signal is used to calibrate
the Host AGTL+ I/O buffer
characteristics to specific
board characteristics.
• Refer to Section 5.3.5.
Table 13-2. MCH Schematic Checklist (Sheet 2 of 3)
Checklist Items Recommendations Comments

Intel Xeon Specifications

General

Brand	Intel
Model	Xeon
Category	Processor
Language	English