本例程是使用STC系列MCU做的模拟串口。用户根据自己的时钟和波特率自行设置后编译下载。使用串口助手向MCU发送数据，MCU收到后原样返回给PC。-This routine is the STC series MCU analog serial. Users according to their own clock and the baud rate to set compiler download. Serial assistant to send data to the MCU, the MCU received and return it unchanged to the PC.