1# UsbDdkInterface 2<!--Kit: Driver Development Kit--> 3<!--Subsystem: Driver--> 4<!--Owner: @lixinsheng2--> 5<!--Designer: @w00373942--> 6<!--Tester: @dong-dongzhen--> 7<!--Adviser: @w_Machine_cc--> 8 9## Overview 10 11Defines a USB DDK API, which is a collection of alternate settings for a particular USB interface. 12 13**Since**: 10 14 15**Related module**: [UsbDDK](capi-usbddk.md) 16 17**Header file:** [usb_ddk_types.h](capi-usb-ddk-types-h.md) 18 19## Summary 20 21### Member Variables 22 23| Name| Description| 24| -- | -- | 25| uint8_t numAltsetting | Number of alternate settings of the USB interface.| 26| struct UsbDdkInterfaceDescriptor* altsetting | Alternate setting of the USB interface.| 27