Agtl+ ( Vref Hdvref [3:0], Havref [1:0] And Ccvref) - Intel Pentium 4 Design Manual

R
16.1.6 AGTL+ ( V
√
® ®
Intel Pentium 4 Processor / Intel
HDVREF [3:0], HAVREF [1:0] and CCVREF)
REF
Recommendations
• Processor must have at least one dedicated
voltage divider. There are four GTLREF
signals on the processor. Keep voltage
divider within 1.5 inches of the first V
pin.
• 82850 MCH requires one dedicated voltage
divider. Voltage divider must be within 1.5
inches of MCH V ball.
REF
• Decouple each voltage divider with a 1 µF
capacitor and each V pin with a 220 pF
REF
capacitor as close to the pin as possible.
• When routing V use a ~12 mil line trace
REF
width.
• Keep other signals 10 mils away from V
signal.
®
850 Chipset Family Platform Design Guide
Reason/Impact/Documentation
• Refer to Section 5.3.
REF
• Refer to Section 5.5.
• This recommendation provides a low
impedance line without the cost of additional
plane or island.
• Refer to Section 5.3.
• This recommendation provides a low
impedance line without the cost of additional
plane or island.
• Refer to Section 5.2.
• V signal must be a clean as possible
REF REF
from noise.
• Refer to Section 5.3.
Layout Review Checklist
273