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# IOUSBDeviceDescriptor

The structure for storing a USB device descriptor.

```
struct IOUSBDeviceDescriptor;
```

## Overview

For information about this descriptor type, see section 9.6.1 of the USB 3.2 specification at <http://www.usb.org>.

## Topics

### Getting the Device Properties

[`uint8_t bLength;`](/documentation/USBDriverKit/IOUSBDeviceDescriptor/bLength)

The length of the descriptor in bytes.

[`uint8_t bDescriptorType;`](/documentation/USBDriverKit/IOUSBDeviceDescriptor/bDescriptorType)

The type of the descriptor.

[`uint16_t bcdUSB;`](/documentation/USBDriverKit/IOUSBDeviceDescriptor/bcdUSB)

The USB specification release number with which the device complies.

[`uint8_t bDeviceClass;`](/documentation/USBDriverKit/IOUSBDeviceDescriptor/bDeviceClass)

The class code indicating the behavior of this device.

[`uint8_t bDeviceSubClass;`](/documentation/USBDriverKit/IOUSBDeviceDescriptor/bDeviceSubClass)

The subclass code that further defines the behavior of this device.

[`uint8_t bDeviceProtocol;`](/documentation/USBDriverKit/IOUSBDeviceDescriptor/bDeviceProtocol)

The protocol that the device supports.

[`uint8_t bMaxPacketSize0;`](/documentation/USBDriverKit/IOUSBDeviceDescriptor/bMaxPacketSize0)

The maximum packet size for endpoint `0`, specified as an exponent value.

[`uint16_t idVendor;`](/documentation/USBDriverKit/IOUSBDeviceDescriptor/idVendor)

The ID of the device’s manufacturer.

[`uint16_t idProduct;`](/documentation/USBDriverKit/IOUSBDeviceDescriptor/idProduct)

The product ID assigned by the manufacturer.

[`uint16_t bcdDevice;`](/documentation/USBDriverKit/IOUSBDeviceDescriptor/bcdDevice)

The release number of the device, specified as a binary-coded decimal number.

[`uint8_t iManufacturer;`](/documentation/USBDriverKit/IOUSBDeviceDescriptor/iManufacturer)

The index of the string descriptor that describes the manufacturer.

[`uint8_t iProduct;`](/documentation/USBDriverKit/IOUSBDeviceDescriptor/iProduct)

The index of the string descriptor that describes the product.

[`uint8_t iSerialNumber;`](/documentation/USBDriverKit/IOUSBDeviceDescriptor/iSerialNumber)

The index of the string descriptor that describes the device’s serial number.

[`uint8_t bNumConfigurations;`](/documentation/USBDriverKit/IOUSBDeviceDescriptor/bNumConfigurations)

The number of configurations that the device supports.


---

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