Platform Clock Routing Guidelines
42
Design Guide
4.1.2
CLK66 Clock Group
In the CLK66 clock group, the driver is the clock synthesizer 66 MHz clock output buffer, and the
receiver is the 66 MHz clock input buffer at the MCH, ICH3-S, and P64H2.
NOTES:
1. For better understanding of the concept, refer to
,
.
2. Assuming no connector.
Figure 4-6. Topology for CLK66
Table 4-4. CLK66 Routing Guidelines
Parameters
Routing Guidelines
Clock Group
CLK66
Topology
Point-to-Point
Reference Plane
Ground referenced (contiguous over entire length)
Characteristic Trace Impedance (Z
0
)
50
Ω
±
10%
Trace Width
5 mils
Trace Spacing
25 mils
Trace Length – L1
0.00” – 0.50”
Trace Length – L2
3.00” – 9.0”
Resistor
R1 = 43
Ω
±
5%
Skew Requirements
All the clocks in the CLK66 group must have < 100 mil skew
between each other.
Clock Driver to MCH
X = (3” – 9.5”)
1
Clock Driver to ICH3-S
X = (3” – 9.5”)
Clock Driver to P64H2
X – 0.34”
2
R1
L1
L2
MCH,
Intel
®
ICH3-S,
Intel
®
P64H2
Clock
Driver
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 ...