Memory Interface Routing Guidelines
72
Design Guide
NOTES:
1. The DIMM displayed represents
any
DIMM.
All DIMMs must be length matched within the specified distance.
A simple method to do this is to length match the MCH to the first DIMM within the specified tolerance and
then match all the signals DIMM to DIMM.
2. There are 8 Data lines (DQ) per group. For simplicity purposes, only the longest and the shortest are
represented here.
3. Indicated lengths measure from the MCH die pad to the DIMM connector pin (including the series resistor).
NOTES:
1. Indicated lengths measure from the MCH die pad to the DIMM connector pin (including the series resistor).
Figure 6-5. Trace Length Matching Requirements for Source Synchronous Routing
MCH
Long
est S
trobe
(DQ
S) =
Y
Shortest Data (DQ) = Y – 100 mils
Shortest Strobe (DQS) = X
Long
est D
ata (
DQ)
= X +
100
mils
Rs
Rs
Rs
Rs
DIMM
Figure 6-6. DQS To CMDCLK Pair Length Matching
MCH
DIMM
CMDCLK length = x
CMDCLK# length = x
Shortest DQS length = x - 1.75"
Longest DQS length = x + 1.75"
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 ...