System Bus Routing Guidelines
62
Design Guide
5.3.2.1
Proper Power Good Usage
Route CPUPWRGD as shown in
. You may choose to isolate PWRGOOD for each
voltage regulator and processor pair in order to recognize individual voltage regulator failures.
NOTES:
1. Trace Z
0
= 50
Ω.
2. Trace spacing = 10 mil.
5.3.2.2
Voltage Translation for INIT#
A voltage translator circuit is required for the INIT# signal for all platforms that use the FWH. The
required routing topology for INIT# is given in
. Do not route a stub when routing to the
processors.
shows the voltage translator circuit.
NOTE:
The total trace length between the ICH3-S pin and the Processor 0 pin must be less than 15 inches.
Figure 5-7. Topology for PWRGOOD (CPUPWRGOOD)
Intel
®
ICH 3-S
Processor 0
Processor 1
0.1" – 3.0"
0.1" – 9.0"
0.1" – 9.0"
VCC_CPU
300
Ω
± 5%
Figure 5-8. INIT# Routing Topology
Intel
®
ICH3-S
Processor 0
Processor 1
0.1" – 3.0"
0.1" – 9.0"
VCC_CPU
200
Ω
± 5%
0.1" – 9.0"
0.1" – 9.0"
Voltage
Translator
FW H
Summary of Contents for Xeon
Page 24: ...Introduction 24 Design Guide This page is intentionally left blank ...
Page 30: ...Component Quadrant Layout 30 Design Guide This page is intentionally left blank ...
Page 52: ...Platform Clock Routing Guidelines 52 Design Guide This page is intentionally left blank ...
Page 66: ...System Bus Routing Guidelines 66 Design Guide This page is intentionally left blank ...
Page 118: ...Intel 82870P2 P64H2 118 Design Guide This page is intentionally left blank ...
Page 146: ...I O Controller Hub 146 Design Guide This page is intentionally left blank ...
Page 148: ...Debug Port 148 Design Guide This page is intentionally left blank ...
Page 210: ...Schematic Checklist 210 Design Guide This page is intentionally left blank ...
Page 220: ...Layout Checklist 220 Design Guide This page is intentionally left blank ...
Page 222: ...Schematics 222 Design Guide This page is intentionally left blank ...