Intel Xeon Processor and Intel E7500/E7501Chipset Compatible Platform Design Guide

Intel
®
Xeon™ Processor and Intel
®
E7500/E7501 Chipset Compatible Platform Design Guide 119
Intel
®
82870P2 (P64H2)
Figure 8-6 shows a device down before a PCI-X riser card. Place a 22 Ω series resistor on the stub
to riser leg, close to the riser itself. This topology can only be run at PCI 66 MHz or below.
8.1.5 PCI-X Two Devices Down Routing Requirements
The following guideline is for a system that uses two devices down on a singe PCI-X channel. A
good example of usage for this configuration is an I/O Processor or RAID device and a SCSI
controller. This channel can be run at PCI-X 100 MHz.
Figure 8-6. Device Down with Stub before PCI-X Riser Card Topology
Table 8-9. Device Down with Stub before PCI-X Riser Card Length Requirements
Configuration
Intel
®
P64H2 to Stub Stub to Riser Stub to Device
Lower Upper Lower Upper Lower Upper
PCI-X 66 MHz, 3 slot riser 3.3” – 5.6” 3.3” – 4.6” 0.2” – 2.3” 0.2” – 1.3” 1.9” – 6.5“ 1.9” – 5.5”
Intel
®
P64H2
P64H2 to Stub
Device
Riser
Stub to Riser
Stub to Device
Figure 8-7. Two Devices Down Card Topology
Table 8-10. Two Devices Down Length Requirements
Configuration
Intel
®
P64H2 to Device
Lower Upper
100 MHz PCI-X 3.5” – 7.0” 3.5” – 7.0”
Intel
®
P64H2
P64 H2 t o
Device
Dev ic e
Dev ic e
P64H2 to
Device