An electric energy meter, a metering chip and its built-in clock signal modulation method

Abstract

The invention discloses an electric energy meter, a metering chip and a built-in clock signal modulation method thereof. According to the method, training bytes sent by a microcontroller chip are counted through the metering chip, and the signal frequency of a built-in clock of the metering chip is obtained through calculation; the signal frequency is then read through the microcontroller chip, the difference between the signal frequency and a preset frequency is calculated, and whether the difference is smaller than the preset difference is judged; when it is judged that the difference is not smaller than the preset difference, the metering chip is controlled to adjust the circuit parameters of the built-in clock, the training bytes are counted again so that a new signal frequency and a new difference can be obtained till it is judged that the difference is smaller than the preset difference; finally, the difference between the signal frequency of the built-in clock obtained by each chip and the preset frequency is made smaller than the preset difference, it is guaranteed that clock signal frequencies of all the chips are basically identical, and the problem of high frequency difference of an RC clock in the prior art is solved.

Description

technical field [0001] The invention relates to the technical field of signal processing, in particular to an electric energy meter, a metering chip and a modulation method for a built-in clock signal thereof. Background technique [0002] Microcontroller chips and metering chips used in energy metering generally use external crystals to achieve the required clock accuracy. If the metering chip can use a built-in RC clock, the cost of electric energy metering applications can be reduced; at the same time, because the external crystal has the risk of stopping vibration, the use of a built-in RC clock in the metering chip is also very important for improving the reliability of the metering chip. help. [0003] However, in the prior art, the integration of RC clocks on the metering chip has the following problems: the individual discreteness of the RC clock frequency is relatively large, and even if a certain price is paid, the RC clock frequency deviation between chips may re...

AI Technical Summary

Problems solved by technology

[0004] In view of this, the present invention provides an electric energy meter, metering chip and its built-in clock signal modulation method to solve the problem of high frequency deviation of RC clock between chips in the prior art

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