PCI-X Layout Guidelines

8.6.5PCI 33 MHz Embedded Mode Topology

Figure 21 and Table 14 provide routing details for a topology with an embedded PCI 33 MHz design.

Figure 21. PCI 33 MHz Embedded Mode Routing Topology

 

EM1

EM3

EM5

EM7

EM9

 

TL EM1

TL EM3

TL EM5

TL EM7

TL EM9

TL1

TL2

TL3

TL4

 

TL5

 

TL EM2

TL EM4

TL EM6

TL EM8

TL EM10

 

EM2

EM4

EM6

EM8

EM10

 

 

 

 

 

B2723 -01

Table 14.

PCI 33 MHz Embedded Routing Recommendations

 

 

 

 

Parameter

Routing Guideline for Lower AD Bus

 

 

 

 

Reference Plane

Route over an unbroken ground plane

 

 

 

 

Board Impedance

60 +/- 15%

 

 

 

 

Stripline Trace Spacing

12 mils, edge to edge

 

 

 

 

Microstrip Trace Spacing

18 mils edge to edge

 

 

 

 

Group Spacing

Spacing from other groups: 25 mils min, edge to edge

 

 

 

 

Breakout

5 mils on 5 mils spacing. Maximum length of breakout region can be 500 mils.

 

 

 

 

Trace Length 1 TL1: From

 

 

41110 signal Ball to first

5.0” max

 

junction

 

 

 

 

 

Trace Length TL2 to TL5 -

0.5” min - 3.5” max

 

between junctions

 

 

 

Trace Length TL_EM1 to

 

 

TL_EM10 from junction to

2.0” min - 3.0” max

 

embedded devices

 

 

 

 

 

Length Matching

Clocks coming from the clock driver must be length matched to within 25 mils.

 

Requirements

 

 

 

 

 

40

Intel® 41110 Serial to Parallel PCI Bridge Design Guide

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Intel 41110 manual PCI 33 MHz Embedded Mode Topology, PCI 33 MHz Embedded Routing Recommendations