Digital phase discriminator based on finite-state machine

Abstract

The invention relates to a digital phase discriminator based on a finite-state machine, and the digital phase discriminator comprises a first synchronous circuit, a second synchronous circuit, a state machine, an add-subtract counter and a storage circuit; the first synchronous circuit, the second synchronous circuit and the storage circuit are connected to the input end of the state machine; the add-subtract counter and the storage circuit are connected with the output end of the state machine, and the add-subtract counter is connected with the storage circuit. According to the phase discriminator, signal synchronization processing is carried out on the input signal input by the first synchronous circuit and the feedback signal input by the second synchronous circuit through the first synchronous circuit and the second synchronous circuit, so that the influence of a metastable state condition on an output result of the phase discriminator is avoided; then, under the control of a state machine, corresponding addition or subtraction processing is performed according to different input conditions; and finally, data storage and output are completed through a storage circuit. Through the operation, the output time of the phase discriminator can be effectively shortened, and the power consumption is reduced.

Description

technical field [0001] The invention belongs to the field of integrated circuits, in particular to a digital phase detector circuit based on a state machine control counter. Background technique [0002] The phase-locked loop is a control system that automatically calibrates the phase of the signal. It compares the frequency phase of the external reference clock signal and the feedback clock signal, and generates a clock signal that is consistent with the frequency phase of the reference signal. With the continuous emergence of new materials and new technologies, the level of semiconductor technology has advanced rapidly. The phase-locked loop is composed of independent discrete devices at the beginning, and later developed into an integrated phase-locked loop composed of analog circuits. After entering the nanometer era, the reduction of feature size makes it more and more difficult to improve the performance of analog circuits, and also induces many leakage current proble...

AI Technical Summary

Problems solved by technology

[0004] Therefore, since the identification time of the current phase detector is not fast enough, a new type of digital phase detector that can help the phase-locked loop to shorten the locking time is needed

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