IEI Technology PCIE-9452, User Manual

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PCIE-9452 PICMG 1.3 CPU Card
Page 14
2.5.3 Intel
®
945GM PCIe x16
2.5.3.1 PCIe x16 Bus Overview
The Intel® 945GM northbridge chipset has a dedicated 16-lane PCIe port for an external
PCIe x16 graphics card. The PCIe x16 graphics card is installed on a compatible PICMG
1.3 backplane and interfaced to the northbridge through the two golden fingers shown in
Figure 2-5 . Note that the 16 lanes of the PCIe x16 northbridge bus are connected to two
golden fingers.
Figure 2-5: PCIe x16 Golden Fingers
2.5.3.2 PCIe x16 Expansion Options
The PCIe x16 can be interfaced to either one PCIe x16 graphics card or a single PCIe x1
expansion card on a compatible PICMG 1.3 backplane.
2.5.3.3 PCIe x16 Bus Specifications
Some of the PCIe x16 bus specifications are listed below.
Compliant with the current PCI Express Base Specification base PCIe
frequency of 2.5GHz
Raw bit rate on the pins is 250Gb/s
Maximum theoretical bandwidth of 4GB/s in each direction resulting in an
8GB/s bandwidth when in PCIe x16 mode
100MHz differential reference clock