UART:Universal Asynchronous Receiver/Transmitter，通用异步接收/发送装置，UART是一个并行输入成为串行输出的芯片，通常集成在主板上，多数是16550AFN芯片。

串行接口是一种可以将接受来自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。一般完成这种功能的电路，我们称为串行接口电路。-UART: Universal Asynchronous Receiver/Transmitter, universal asynchronous receiver/transmitter device, UART is a parallel input into serial output of the chip, usually integrated on the motherboard, most of 16550AFN chip.

Serial interface is able to accept the characters from the CPU of the parallel data into serial data stream continuously sent, at the same time will receive the serial data stream into parallel data characters in the supply of the device CPU. General to complete the circuit of this function, we call the serial interface circuit.