Baud rate calibration circuit and serial chip

Abstract

The application relates to the technical field of communication, and provides a baud rate calibration circuit and a serial port chip. The calibration circuit includes: a first counter connected to the receiving module of the serial port chip, the first counter is used to record the first low-level duration of the data frame received by the receiving module; a second counter connected to the receiving module, the first The second counter is used to receive bit sampling pulses and record the number of bit sampling pulses in the first low-level duration; wherein, the bit sampling pulses are generated by sampling the data frame by the receiving module according to the current baud rate of the receiving module; division The device is connected with the first counter and the second counter, and the divider is used to calculate the calibration baud rate according to the first low-level duration and the number of bit sampling pulses in the first low-level duration; the selector is connected with the receiving The module and the divider are connected, and the selector is used to output the calibration baud rate to the receiving module.

Description

technical field [0001] The application belongs to the technical field of communication, and in particular relates to a baud rate calibration circuit and a serial port chip. Background technique [0002] The baud rate is a measure of the transmission rate of symbols, and 1 baud means that 1 symbol is transmitted per second. In a common serial communication system, 1 symbol corresponds to 1 bit, so 1 baud can also be understood as transmitting 1 bit per second. And in a common serial communication system, the sending end and the receiving end must agree on a consistent baud rate in advance to achieve normal communication, ensuring that the data sent by the sending end is the same as the data received by the receiving end. [0003] However, the inventors of the present application have found that there are at least the following problems in the prior art: due to the internal clock deviation of both ends of the communication, the baud rate of the data received by the receiving ...

AI Technical Summary

Problems solved by technology

[0003] However, the inventors of the present application have found that there are at least the following problems in the prior art: due to the internal clock deviation of both ends of the communication, the baud rate of the data received by the receiving end will not match the baud rate of the data sent by the sending end (such as figure 1 , figure 2 As shown), there will be abnormal reception of data at the receiving end, reducing the reliability of data transmission, and even affecting normal data communication

This method cannot achieve real-time calibration of the baud rate, and is not suitable for communication systems where the communication environment changes too quickly, and has great limitations.

Images