Mobile Intel Pentium 4 Processor - M and Intel 845MP/MZ Chipset Platform Design Guide

Mobile Intel
®
Pentium
®
4 Processor-M and Intel
®
845MP/845MZ Chipset Platform
94 Design Guide
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The Vref divider network should be placed as close to the AGP interface as is practical to get the benefit
of the common mode power supply effects. However, the trace spacing around the Vref signals must be
a minimum of 25 mils to reduce crosstalk and maintain signal integrity.
All resistors used in above reference generation schemes should have ± 1% tolerance.
6.3.9. Compensation
The MCH-M AGP interface supports resistive buffer compensation (RCOMP). For Printed Circuit
Boards with Characteristics impedance of 55 Ω, tie the AGP_RCOMP pin to a 36.5 Ω, 1% pull-down
resistor (to ground) via a 10-mil wide, very short (
≈0.5 inches) trace.