Automatic Baud rate detection method and detection module

Abstract

The invention discloses an automatic Baud rate detection method. According to the method, a Baud rate counter counts continuously from a start moment to a first moment, from the first moment to a second moment and from the second moment to a third moment to obtain a first Baud rate value, a second Baud rate value and a third Baud rate value respectively; a Baud rate generator of an asynchronous receiving transmitter uses the first Baud rate value, the second Baud rate value and the third Baud rate value as the Baud rate to generate a first Baud rate synchronous signal, a second Baud rate synchronous signal and a third Baud rate synchronous signal; received data which are received with the Baud rate synchronous signals as sampling points and appointed data are compared, and the automatic Baud rate detection is completed if the received data and the appointed data are identical. According to the automatic Baud rate detection method, start bit time detection and semi-bit detection are further included. The invention further discloses an automatic Baud rate detection module which comprises a precision Baud rate detection unit, a start moment detection unit, a semi-bit detection unit and a data frame matching detection unit. According to the automatic Baud rate detection method and the automatic Baud rate detection module, more precise and faster automatic Baud rate detection can be provided compared with the prior art.

Description

technical field [0001] The invention relates to the technical field of data communication, in particular to an automatic baud rate detection method and a detection module applied in the field of large-scale serial port data communication in the Beidou navigation system. Background technique [0002] In a Beidou navigation system chip, the Universal Asynchronous Receiver Transmitter (UART) provides an asynchronous communication interface as the main way for the system to exchange data with external host / slave devices. When communicating with the host, it is used as the main interface for program download / update; when communicating with the slave device, it is used to output navigation and positioning information. [0003] The structure of a typical Universal Asynchronous Receiver Transmitter (UART) see figure 1 . For the sending part, the data to be sent t1 (8bit) is transferred from the bus interface circuit 11 to the sending buffer 13; when the sending controller 14 enter...

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Problems solved by technology

[0005] Due to the fact that the data may be biased after being converted and quantized during transmission, the length of the high and low levels of each bit of the formed square wave is not equal, so the baud rate calculated according to the low level of the start bit may be too high or biased. Small, the result is that the automatic baud rate detection is unsuccessful or the detection is successful but the obtained baud rate cannot meet the transmission error requirements

Therefore it can be seen that there are some problems in the above-mentioned baud rate detection method of the prior art

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