Adaptive baud rate detection method for serial bus communication interface

The serial bus communication interface has the characteristics of convenient connection and simple protocol, such as RS232, RS422 and RS485, which are widely used in aerospace, security monitoring and other industrial fields. As one of the important parameters of serial bus communication interface, baud rate directly affects whether the data can be analysed correctly. According to the data frame protocol of serial bus communication interface, an adaptive baud rate detection method is proposed based on FPGA. By detecting the negative pulse width on the serial data line, the maximum common divisor of the negative pulse width is calculated, and the abnormal baud rate is continuously filtered from the candidate baud rate table according to the maximum common divisor, and finally the effective baud rate is output. The adaptive detection and matching of the baud rate are realized, and the flexibility and generality of the serial bus interface are significantly improved. Simulation results show the feasibility and effectiveness of the proposed method.