An all-digital frequency measurement system based on clock phase shift

Abstract

The invention provides an all-digital frequency measurement system based on clock phase shift. The system comprises a reference clock module, a counter module, a trigger module, a time division multiplexing module, a register module, a status decoding module and a calculating module. The reference clock module provides a plurality of paths of high-frequency clock signals having same frequency and having phase difference; the counter module carries out pulse value counting on input signals and one path of high-frequency clock signal; the trigger module, the time division multiplexing module and the register module are used for locking and storing state vector of each path of high-frequency clock at beginning time and end time when carrying out counting on the input signals; the status decoding module carries out decoding on the state vectors of the plurality of paths of high-frequency clocks; and a frequency measurement value of the input signals is obtained through the calculating module. The method prevents the technical scheme of improving frequency resolution by simply improving clock frequency of a conventional frequency measurement method, and converts improvement of clock frequency into the plurality of paths of high-frequency clocks having phase difference, thereby realizing clock subdivision and improving frequency measurement resolution.

Description

technical field [0001] The invention relates to the technical field of frequency measurement, in particular to an all-digital frequency measurement based on clock phase shifting, which can improve the frequency measurement resolution without increasing the reference clock frequency and prolonging the test time, and is suitable for high resonance sensors. Accurate frequency measurement needs. Background technique [0002] Resonant sensors such as vibrating beam accelerometers and resonant pressure gauges have the outstanding advantages of high resolution, direct frequency pulse output, and easy direct matching with subsequent digital processing systems. In order to ensure the output resolution of the sensor, high-resolution full digital Frequency measurement method. [0003] In the existing frequency measurement technology, the multi-cycle synchronization method and the analog interpolation method are mainly used to realize high-resolution frequency measurement. [0004] Th...

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Problems solved by technology

However, the interposer is generally implemented by charging and discharging a capacitor, which requires an analog-digital hybrid circuit with a complex circuit structure, and is often used in special frequency counting equipment that does not require high volume and power consumption.

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