BAUD RATE CALIBRATION CIRCUIT AND SERIAL CHIP

The present disclosure relates to communication technologies, and provides a circuit for calibrating a baud rate and a serial port chip. The circuit includes: a first counter which is connected to a receiving module of a serial port chip and configured to record a first low level duration of a data frame received by the receiving module; a second counter which is connected to the receiving module and configured to: receive a bit sampling pulse, and record a quantity of the bit sampling pulse in the first low level duration, where the bit sampling pulse is generated from sampling the data frame by the receiving module according to a current baud rate of the receiving module; a divider, which is connected to the first counter and the second counter and configured to calculate a calibration baud rate according to the first low level duration and the quantity of the bit sampling pulse in the first low level duration; and a selector, which is connected to the receiving module and the divider and configured to output the calibration baud rate to the receiving module.