UART波特率检测电路的FPGA设计算法与实现  

FPGA-based design algorithm and realization of baud rate detection circuit for UART

作　　者：吴朝晖[1] 曲立国[1] WU Zhaohui;QU Liguo(School of Physics and Electronic Information,Anhui Normal University,Wuhu 241000,China)

机构地区：[1]安徽师范大学物理与电子信息学院,安徽芜湖241000

出　　处：《现代电子技术》2022年第20期41-44,共4页Modern Electronics Technique

基　　金：2020省级质量工程项目(2020szsfkc0420)。

摘　　要：为了检测异步串行通信线上传输信号所采用的时钟波特率,文中提出一种基于检测信号波形特征参数的方法,用于分析计算可能的时钟波特率。相比传统检测法,文中方法对每种信号都能进行检测,不需要发送特定的信号,波特率计算准确,虽然占用的电路资源稍多,但检测效率高。首先对通信线路上每种信号波形进行分析研究,得到它们的特征参数,即每个波形都有确定的间隔数和间隔宽度比例;然后对这些参数进行归纳,得出约93%的波形都具有唯一的特征参数,只有7%的波形特征参数可能不唯一;最后,使用Verilog HDL语言设计实现UART波特率检测电路,包括信号边沿检测、信号边沿计数、有限状态机、信号脉冲宽度计数以及波特率计算等。仿真检测和FPGA开发板的下载验证结果表明,文中方法波特率检测正确,对于具有唯一特征参数的信号,能够给出成功检测的标志。In order to detect the clock baud rate used to transmit signal in the asynchronous serial communication line,a method based on the characteristic parameters of detection signal waveform is proposed to analyze and calculate the possible clock baud rate. In comparison with the traditional detection method,the method proposed in this paper can detect each signal without sending any specific signal,its baud rate calculation is accurate,and although it may occupy a little more circuit resources,the detection efficiency is high. Each signal waveform in the communication line is analyzed and studied to obtain their characteristic parameters,that is,each waveform has a certain interval number and interval width ratio. After summarizing these parameters,it is concluded that about 93% of the waveforms have their own unique characteristic parameters,and only7% of the waveform have no their unique characteristic parameters. Verilog HDL language is used to design and realize the baud rate detection circuit for the UART(universal asynchronous receiver/transmitter),in which signal edge detection,signal edge counting,finite state machine,signal pulse width counting and baud rate calculation are included. The results of simulation test and FPGA development board download verification show that the baud rate detection of the method proposed in this paper is correct,and for signals with unique characteristic parameters,it can give a sign of successful detection.

关 键 词：波特率检测电路 波形特征检测 UART FPGA 特征参数 仿真测试 

分 类 号：TN919.3-34[电子电信—通信与信息系统]