Design Guide
65
System Bus Routing Guidelines
5.3.8
TESTHI[6:0] Routing Guidelines
All TESTHI[6:0] pins must be connected to VCC_CPU via pull-up resistors with a termination
value within 20% of the signal impedance (50
Ω
± 20%). TESTHI[3:0] may all be tied together and
pulled up to VCC_CPU with a single, 50
Ω
± 20% resistor if desired. TESTHI[6:5] may also be
tied together and pulled up to VCC_CPU with a single 50
Ω
± 20% resistor. However, boundary
scan testing will not be functional if any TESTHI pins are pulled up together. TESTHI4 must
always be pulled up independently from the other TESTHI pins regardless of the usage of
boundary scan.
5.3.9
SKTOCC# Signal Routing Guidelines
The SKTOCC# signal is an output from the processor used as an indication of whether a processor
is installed or not. It is asserted low when a processor is installed in the socket, and floats when no
processor is present. If this signal is used on the board, the designer can use a pull-up to prevent
floating. SKTOCC# can be used to disable the VRM or VRD output for unpopulated processor
sockets or the power supply output when no processors are installed and other features.
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 ...
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