REV REV 复位值:10h只读 RevisionThis read-only field contains the BCD representation of the version of the HCI specification that is implemented by this HC. For example, a value o...
Figure 3-1 shows four main focus areas of a Universal Serial Bus (USB) system. These areas are the Client Software/USB Driver, Host Controller Driver (HCD), Host Controller (HC), ...
Hub descriptors are derived from the general USB device framework. Hub descriptors define a hub device and the ports on that hub. The host accesses hub descriptors through the hub...
A device descriptor describes general information about a USB device. It includes information that applies globally to the device and all of the device’s configurations. A USB dev...