最常用的两种串口异步通信协议就是8位数据模式与9位数据模式,本文对这两种通信协议做了详细分析,对不同协议之间能否正常通信也进行了分析,尤其是9位模式发送数据、8位模式接收数据的可行性,对于这种方式从协议上进行了分析,并进行了实验验证。在实际应用中出现通信错误时,从通信波形进行通信协议分析,用接收数据中转的方法来查找与确认是否为通信协议设置的问题。

The two most commonly used serial asynchronous communication protocols are 8bit data mode and 9bit data mode.This paper makes a detailed analysis of these two communication protocols.It also analyzes whether the different protocols can communicate normally,especially the feasibility of sending data in 9bit mode and receiving data in 8bit mode.This method has been analyzed from the protocol and verified by experiments.This paper also gives the method of how to analyze the communication protocol from the source of the communication waveform when communication errors occur in practical applications,and how to find and confirm whether it is the problem of the communication protocol setting by using the method of receiving data transfer.