扩展串口的常用芯片16C554，自带四通道，含16字节FIFO，中文版更易读懂。,Extension of the commonly used serial port chip, the Chinese version easier to read.

环形缓冲区的实现原理,在通信程序中，经常使用环形缓冲区作为数据结构来存放通信中发送和接收的数据。环形缓冲区是一个先进先出的循环缓冲区，可以向通信程序提供对缓冲区的互斥访问-The principle of the ring buffer, in the communication process, often use ring buffers to store the data as a data structure to send and receive communications. FI