---
title: IOUSBInterfaceAssociationDescriptor
framework: IOKit
role: symbol
role_heading: Structure
platforms: [Mac Catalyst 13.0+, macOS 10.3+]
path: iokit/iousbinterfaceassociationdescriptor
---

# IOUSBInterfaceAssociationDescriptor

## Declaration

```occ
typedef struct IOUSBInterfaceAssociationDescriptor {
    ...
} IOUSBInterfaceAssociationDescriptor;
```

## Overview

Overview USB Inerface Association Descriptor. ECN to the USB 2.0 Spec. See the USB Specification at http://www.usb.org.

## Topics

### Instance Properties

- [bDescriptorType](iokit/iousbinterfaceassociationdescriptor/1426207-bdescriptortype.md)
- [bFirstInterface](iokit/iousbinterfaceassociationdescriptor/1425592-bfirstinterface.md)
- [bFunctionClass](iokit/iousbinterfaceassociationdescriptor/1426096-bfunctionclass.md)
- [bFunctionProtocol](iokit/iousbinterfaceassociationdescriptor/1425830-bfunctionprotocol.md)
- [bFunctionSubClass](iokit/iousbinterfaceassociationdescriptor/1426264-bfunctionsubclass.md)
- [bInterfaceCount](iokit/iousbinterfaceassociationdescriptor/1426355-binterfacecount.md)
- [bLength](iokit/iousbinterfaceassociationdescriptor/1425365-blength.md)
- [iFunction](iokit/iousbinterfaceassociationdescriptor/1426026-ifunction.md)

## See Also

### Related Documentation

- [IOUSBInterfaceAssociationDescriptor](iokit/usb_h_user-space/iousbinterfaceassociationdescriptor.md)