Universal Serial Bus (USB)

The PCH implements an xHCI USB controller which provides support for up to eight USB 2.0 signal pairs, four USB 3.0 and two USB 3.1 signal pairs.

The xHCI controller supports wake up from sleep states S1-S4. The eXtensible Host Controller (xHCI) supports up to 64 devices for a max number of 2048 Asynchronous endpoints (Control/Bulk) or max number of 128 Periodic Endpoints (Interrupt/isochronous).

Each walk-up USB 3.2 capable port contains one USB 2.0 signal pair and one USB 3.2 signal pair.

The USB subsystem also supports Dual Role Capability. The xHCI is paired with a standalone eXtensible Device Controller Interface (xDCI) to provide dual role functionality. There is only one endpoint supported.

The xDCI shares all USB ports with the host controller, with the ownership of the port being decided based the USB Power Delivery specification. Since all the ports support device mode, xDCI enabling must be extended by System BIOS. While the port is mapped to the device controller, the host controller Rx detection must always indicate a disconnected port.