Digital circuit noise filter and digital filtering method

Abstract

The invention discloses a digital circuit filter. The digital circuit filter comprises an independent glitch filtering module and a correlated glitch filtering module, wherein the independent glitch filtering module is used for receiving an input signal and filtering independent glitches in the signal; the signal input end of the correlated glitch filtering module is connected with the output end of the independent glitch filtering module; the correlated glitch filtering module is used for receiving an input signal from which the independent glitches are filtered and filtering glitches correlated with a signal waveform; the glitches correlated with the signal waveform comprise glitches occurring before the signal waveform and glitches occurring after the signal waveform; the distances between the glitches correlated with the signal waveform and the signal waveform do not surpass the pulse widths of the glitches; and the independent glitch filtering module and the correlated glitch filtering module are used for distinguishing and filtering the glitches in a time direction. The invention further discloses a corresponding digital filtering method. According to the digital filter and the digital filtering method, a method for distinguishing and filtering the glitches in the time direction is adopted, so that pulse noise with large amplitude can be eliminated, and clock or signal errors are avoided.

Description

technical field [0001] The invention relates to the technical field of digital circuits, in particular to a digital circuit noise filter and a digital filtering method. Background technique [0002] Chips are often subject to external disturbances in the system, such as electrostatic discharge, momentary power switch jumps, or momentary signal jitter caused by lightning. The above interference will introduce short-term but large-amplitude noise pulses, the effect of which is similar to glitches for digital circuits, which may cause clock pulse errors or signal transmission errors. [0003] For the glitches caused by crosstalk, the general approach is to use a Schmitt trigger, so that the amplitude of the input signal will not cause the output signal to jitter within a certain range. The input and output curves of the Schmitt trigger are as follows figure 1 shown. When the input is less than -T and increases from -T to T, the output is -M; when the input is greater than T ...

AI Technical Summary

Problems solved by technology

If the input signal is a control signal or a data signal, a transmission error will occur

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