数据的读取：串口通信串口按位发送和接收字节，可以将来自CPU的并行数据字符转换为连续的串行数据流发送出去，同时可将接受的串行数据流转换为并行的数据字符供给CPU的器件使用。串口通信最主要的参数是波特率、数据位、停止位和奇偶校验。(The data read: serial communication serial port by sending and receiving bytes, parallel data characters from the CPU into a continuous serial data stream is sent, and will accept the serial data stream conversion device for data parallel use of CPU supply characters.)