The key features of the PCI express hard IP include endpoint and rootport support, a rev 2.0 compliant protocol stack, three link widths, two payload sizes, and high throughput. Supporting both endpoint and rootport means that the user can configure the Cyclone® IV GX device to control the PCI express bus, eliminating the need for a specific arbiter. Because of the 2.0 compliant protocol stack the user gets a verified and integrated transaction layer, data link layer, and physical layer to make the PCI express link easier to design and verify.