The SBC’s PCI Express links drive the PCIe card slots directly. An additional x4 PCIe link from the SBC enables a dual-channel PCIe-to-PCI-X bridge chip to interface the PCI-X slots into the system. The 32-bit/33MHz PCI slots are driven directly from the SBC’s optional edge connector D PCI interface. Twelve option card slots on this PCI Express backplane support PCIe, PCI-X and PCI plug-in I/O cards typically used in military and industrial automation platforms.