Strengthening method of digital filter based on PI type CDR

Abstract

The invention discloses a strengthening method of a digital filter based on PI type CDR. The method aims at solving the problem of abnormal phase interpolation coefficient caused by the situation that the digital filter based on PI type CDR is easily influenced by a space high-energy particle. The technical scheme is as follows: introducing a strengthening circuit containing a rollback judgment module and a selector to monitor the current_state output by a phase tracking accumulator and the last_state output by a register block of the digital filter, and judging the monitoring result; the output of the register block maintaining the unchanged value of the former clock period thereof if monitoring the abnormal current_state. Through the adoption of the method disclosed by the invention, the single event effect propagated to the output end of the phase tracking accumulator can be effectively monitored and the rollback can be implemented in the premise of not introducing extra time delay, the influence caused by the single event effect to the output of the register block, namely the final phase interpolation coefficient, is avoided.

Description

technical field [0001] The invention relates to a method for strengthening a digital filter circuit in a PI type (based on phase interpolation, Phase Interpolator, referred to as PI) CDR (Clock and Data Recovery, referred to as CDR), especially for suppressing the Reinforcement method for single event effect of digital filter circuit in space environment. Background technique [0002] There are a large number of high-energy particles (protons, neutrons, heavy ions, etc.) and high-energy rays in the universe, and integrated circuits will produce single-event effects under the bombardment of these high-energy particles and high-energy rays. Specifically, after the combinational logic unit (such as AND, NOT gate, etc.) in the integrated circuit is bombarded, it will generate a single event transient (Single Event Transient, SET for short) pulse; After the bombardment, a Single Event Upset (SEU) will occur. Both SET and SEU are likely to be passed backwards, causing errors in ...

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