This section summarizes USB class specifications and standards for host controllers.
4. USB host controller complies with OpenHCI or UHCI
| Required | ||
The host controller must be compliant with either OpenHCI for USB (published by Compaq, Microsoft, and National Semiconductor) or Universal HCI (UHCI; published by Intel).
Microsoft intends to support only these two USB host controller implementation standards. Hardware manufacturers who design to one of these specifications should not require an additional device driver for their host controller.