![]() In the transfer, the request type is GET DESCRIPTOR and the recipient is the device. The host obtains the device descriptor through a control transfer. A device must not change the information contained in the device descriptor during the lifetime of a connection, including during power state changes. The device descriptor also indicates the total number of configurations that the device supports.Ī device might report different information in its device descriptor when the device is connected to the host computer in a high speed capacity than when it's connected in a full speed capacity. You can view the those identifiers in Device Manager. The USB driver stack uses bcdDevice, along with idVendor and idProduct, to generate hardware and compatible IDs for the device. The bcdDevice value indicates the device-defined revision number. ![]() For example, 0x0200 indicates that the device is designed as per the USB 2.0 specification. The bcdUSB field indicates the version of the USB specification to which the device conforms. In the Details tab, the Hardware Ids property value indicates the hardware ID ("USB\ XXX") that is generated by Windows. To view the hardware ID of a particular device, open Device Manager and view device properties. Windows uses those field values to construct a hardware ID for the device. For example, the idVendor and idProduct fields specify vendor and product identifiers, respectively. Windows uses that information to derive various sets of information. ![]() The USB_DEVICE_DESCRIPTOR structure describes a device descriptor. ![]() This topic describes the USB_DEVICE_DESCRIPTOR structure and includes information about how a client driver can send a get-descriptor request to obtain the device descriptor.Įvery Universal Serial Bus (USB) device must be able to provide a single device descriptor that contains relevant information about the device. The device descriptor contains information about a USB device as a whole. ![]()
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