PDIUSBD12的与上位机通过USB通信的代码，基于51内核，经典菜鸟学习USB的程序-PDIUSBD12 with the host computer through the USB communication code, based on 51 core, the classic rookie USB study procedures

PDIUSBD12固件编程简单实例，USB设备配置后，使与P1口连接的LED全亮-PDIUSBD12 s easy firmware programming example, the LED lights that are connected with P1-wide will be lighted after usb device is configurated.