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
Design Guide 153
R
Figure 83. Topology for AGPCLK to AGP Connector
A
R1
Clock
Driver
AGP
Device
B C
AGP
Connector
Trace on AGP
Card
Figure 84. Topology for AGPCLK to AGP Device Down
A
R1
Clock
Driver
AGP
Device
B
Table 52. AGPCLK Routing Guidelines
Parameter Routing Guidelines
Clock Group AGPCLK
Topology Point to point
Reference Plane Ground Referenced (Contiguous over entire Length)
Characteristic Trace Impedance (Zo) 55 Ohms ± 15%
Trace Width 4 mils
Trace Spacing 20 mils
Spacing to other traces 20 mils
Trace Length – A 0.00” to 0.50”
Trace Length – B (CLK66 Trace B) – 4”
Trace Length – C Routed 4” per the AGP Specification
Resistor R1 = 33 Ohms ± 1%
Skew Requirements Should have minimal (~ 0) skew between the AGPCLK
and the clocks in the CLK66 clock group.