Hub Interface 2.0 Length Matching - Intel Pentium M Processor Design Manual

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Intel Pentium M Processor and Intel
Hub Interface
Figure 75.

Hub Interface 2.0 Length Matching

NOTES:
1. All signal lines with arrows depict the total length of the signal including the mother board trace length, MCH
package trace length, and Intel
2. PUSTRBF and PUSTRBS length matching is the same as for PSTRBF and PSTRBS.
3. This figure is only an example for an implementation with the device on the motherboard. For an
implementation with the Hub Interface device on a riser card, simply replace both instances of 0.25 inch
with 0.125 inch.
4. In the example above, HI[x], HI[y], and HI[z] represent Hub Interface data signals. The other six data signals
in the group must also be matched within 0.25 inch. The associated strobe pair must be within 1.0 inch of
the longest data signal.
The Hub Interface 2.0 has a minimum trace length requirement of three inches, and a maximum
trace length requirement of 20 inches for a device on the motherboard implementation for all Hub
Interface signals (using an internal routing layer on the recommended stack-up). However, for a
device on an adapter card plugged in a Hub Interface 2.0 connector, the maximum motherboard
trace length is 14 inches. This allows three inches for card routing and three inches for connector
skew. For a riser card topology, the maximum trace length would reduce by three inches to (11-Y)
inches, where Y is the riser card trace length. The riser must be built to not exceed the maximum
trace length with the motherboard routed length.
116
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E7501 Chipset Platform
HI[x]
HI[y]
HI[z]
PSTRBF
PSTRBS
- OR -
PSTRBF
PSTRBS
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P64H2 package trace length.
0.25"
1.0 "
0.25"
Design Guide