说明：  c51用串口通信源码,包括调试 1.发送：向总线上发命令 2.接收：从总线接收命令，并分析是地址还是数据。 3.定时发送：从内存中取数并向主机发送.
(decoder serial communication with the source code, including a debugger. Send : Bus made to order two. Acceptance : Bus from receiving orders and analysis of data or address. 3. Timing this : from memory a few sent to the mainframe.)