本程序实现USB鼠标的功能.对D12芯片的命令使用、USB标准请求格式、USB各种描述符以及描述符返回等作了详细的介绍.-This procedure realize the function of the USB mouse. Command for D12 chips use format, USB, USB standard request various descr iptors and the return of the descr iptor has made the detaile