Pci-X Riser Card Topology; Device Down Before Pci-X Riser Card Topology - Intel Pentium M Processor Design Manual

Figure 85
used, the channel may be run up to PCI-X 133 MHz. When a three slot riser is used, the channel
may be run up to PCI 66 MHz.
Figure 85.

PCI-X Riser Card Topology

Table 65. PCI-X Riser Card Length Requirements
PCI-X 133 MHz, 1 slot riser
PCI-X 66 MHz, 3 slot riser
Figure 86
riser is used, the channel may be run up to PCI-X 100 MHz. If a three slot riser is used, the channel
may be run up to PCI-X 66 MHz.
Figure 86.

Device Down Before PCI-X Riser Card Topology

Table 66. Device Down Before PCI-X Riser Card Length Requirements
Configuration
PCI-X 100 MHz, 1 slot riser
PCI-X 66 MHz, 3 slot riser
Figure 87
slot riser requires a 10 Ω series resistor on the riser between the riser fingers and the connector. The
three slot riser configuration cannot be run at PCI 66 MHz. It requires a 15 Ω series resistor on the
baseboard between the Intel
resistor is also need on the riser itself between the riser card fingers and the first connector.
Design Guide
®
Intel Pentium
shows a PCI-X channel with a single connector used for a riser. When a one slot riser is
Intel
P64H2
Configuration
shows a PCI-X channel with a device down before a riser card connector. If a one slot
®
Intel
P64H2
shows a riser card topology with a device down after the riser card connector. The one
® P64H2 and the Riser connector closer to the riser. A second 15 Ω
®
M Processor and Intel
®
P64H2 to Riser
®
Intel P64H2 to Riser
Lower
1.0" – 7.25"
1.0" – 8.25"
Dev ice
P64H2 to Dev ice
®
Intel P64H2 to Device
Lower Upper
0.0" – 6.0" 0.0" – 5.0"
1.0" – 6.0" 1.0" – 4.0"
®
E7501 Chipset Platform
®
Intel 82870P2 (Intel P64H2)
Riser
Upper
1.0" – 6.5"
1.0" – 3.8"
Riser
Dev ice to Riser
Device to Riser
Lower Upper
0.0" – 6.0" 0.0" – 5.0
1.0" – 4.0" 1.0" – 4.0"
127