Time synchronization, also known as clock synchronization, aims to coordinate multiple independent clocks and adjust their operations to be consistent. However, after a period of time, clock timing differences between devices may still occur due to clock drift and slight differences in their timing rates. The difference in clock timing will cause a variety of problems. Although there are many solutions to solve this phenomenon, the best solution must be determined by the actual situation. In serial communication, clock synchronization can refer to clock recovery, that is, frequency synchronization, as opposed to phase synchronization. This kind of clock synchronization is used in telecommunications to automatically detect the synchronization and baud rate. At present, in many communication scenarios and positioning scenarios, the clock synchronization accuracy between different devices is required to be very high; and when the devices form a network, digital synchronization must provide accurate timing for the network to ensure its normal operation.