随着多微机系统的应用和微机网络的发展，通信功能越来越显得重要。串行通信是在一根传输线上一位一位地传送信息.这根线既作数据线又作联络线。串行通信作为一种主要的通信方式，由于所用的传输线少，并且可以借助现存的电话网进行信息传送，因此特别适合于远距离传送。在串行传输中，通信双方都按通信协议进行，所谓通信协议是指通信双方的一种约定。约定对数据格式、同步方式、传送速度、传送步骤、纠错方式以及控制字符定义等问题做出统一规定，通信双方必须共同遵守。-With the application of multi-microcomputer systems and computer networks, communication becomes less important. Serial communication is a one in a transmission line to transmit information, which lines both for the data line and make contact line. Serial communication as a primary means of communication, since the transmission line with less, and can make use of existing telephone network for information transmission, it is particularly suitable for long-distance transmission. In serial transmission, the communication protocol for communication by both sides, the so-called communication protocol is an agreement the two sides. Agreement on data formats, synchronization, transmission speed, transmission procedures, error correction, and control characters are defined to make uniform provisions and other issues, communication, both parties must abide by.