Asynchronous serial port communication baud rate automatic detection device and method

Abstract

The invention discloses an asynchronous serial port communication baud rate automatic detection device and method. The detection device comprises an edge detection module, a pulse width counting module, a minimum pulse width module and a table look-up module which are connected in sequence. The detection method comprises the following steps: receiving an asynchronous serial port signal, and sampling the asynchronous serial port signal through a sampling clock signal with a fixed frequency to obtain a rising edge signal and a falling edge signal of the asynchronous serial port signal; generating a counting enable signal according to the rising edge signal or the falling edge signal, and obtaining the effective time length of the enable signal in real time to obtain a high-level or low-levelbit width count value; comparing the high-level or low-level bit width count value with the minimum pulse width count value, and outputting a smaller value ; and querying a Baud rate and bit width relation table stored in the minimum pulse width module according to the value output by the minimum pulse width module to obtain the Baud rate of the asynchronous serial port sending data.

Description

technical field [0001] The invention relates to a baud rate detection technology, in particular to an asynchronous serial port communication baud rate automatic detection device and a method thereof. Background technique [0002] GPS / Beidou satellite positioning, navigation and timing and synchronous timing between mobile communication base stations, position and time information are all sent through the asynchronous serial port, and the TOD message is sent regularly, and the device receiving the serial TOD message receives the TOD message , parse the message data to obtain the synchronization time information. [0003] The baud rate of the TOD message sending the timing information is configurable, usually the default is 9600bps, and it can also be set to other common baud rates, such as the lowest 4800bps and the highest 115200bps. Therefore, the device receiving the TOD message needs to know the baud rate of the TOD message to communicate normally. When the baud rate of ...

AI Technical Summary

Problems solved by technology

The disadvantage is that the software sequentially executes the process, and the detection time is long, which needs to be completed by running the corresponding application software with the CPU processor or MCU microcontroller

[0008] This interrupt calculation method through the CPU occupies CPU hardware resources, and the software driver is not conducive to transplantation, and the accuracy is low

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