<trid="row71857914585"><tdclass="cellrowborder"valign="top"headers="mcps1.2.4.1.1 "><pid="p1318619155811"><aname="p1318619155811"></a><aname="p1318619155811"></a>struct UsbRequest *UsbAllocRequest(const UsbInterfaceHandle *interfaceHandle, int isoPackets, int length);</p>
<trid="row12422102092613"><tdclass="cellrowborder"valign="top"headers="mcps1.2.4.1.1 "><pid="p194231720102610"><aname="p194231720102610"></a><aname="p194231720102610"></a>struct UsbRawRequest *UsbRawAllocRequest(const UsbRawHandle *devHandle, int isoPackets, int length);</p>
USB ACM设备核心代码路径为drivers\peripheral\usb\gadget\function\acm\cdcacm.c,其使用示例如下所示,首先根据描述符创建设备,然后获取接口,打开接口,获取Pipe信息,接收Event事件,接着进行USB通信(读写等),设备卸载时候,关闭接口,停止Event接收,删除设备。