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# IOUSBInterfaceAssociationDescriptor

The USB Interface Association Descriptor.

```
struct IOUSBInterfaceAssociationDescriptor;
```

## Overview

This type defines the ECN to the USB 2.0 Spec. See the USB Specification at <http://www.usb.org>. USB 3.0 9.6.4: Interface Association.

## Topics

### Accessing the Descriptor Properties

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

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

[`uint8_t bFirstInterface;`](/documentation/USBDriverKit/IOUSBInterfaceAssociationDescriptor/bFirstInterface)

[`uint8_t bInterfaceCount;`](/documentation/USBDriverKit/IOUSBInterfaceAssociationDescriptor/bInterfaceCount)

[`uint8_t bFunctionClass;`](/documentation/USBDriverKit/IOUSBInterfaceAssociationDescriptor/bFunctionClass)

[`uint8_t bFunctionSubClass;`](/documentation/USBDriverKit/IOUSBInterfaceAssociationDescriptor/bFunctionSubClass)

[`uint8_t bFunctionProtocol;`](/documentation/USBDriverKit/IOUSBInterfaceAssociationDescriptor/bFunctionProtocol)

[`uint8_t iFunction;`](/documentation/USBDriverKit/IOUSBInterfaceAssociationDescriptor/iFunction)


---

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