Signal Shaping Dual Modular Redundancy for Soft Error Tolerant Finite Impulse Response Filters

A technique to protect finite impulse response (FIR) filters against soft errors is presented. The approach is based on the use of two copies of the FIR filter. In one of the copies, preprocessing of the input and a postprocessing of the output are added. In the event of a soft error, the outputs of the filters differ or mismatch for one or more samples. The additional processing introduced in the second copy of the filter ensures that the mismatch patterns are unique to each copy. Hence, the copy in error can be identified and the output of the other copy selected as the final error protected filter output. The proposed scheme can efficiently correct isolated soft errors at lower cost than general techniques, such as triple modular redundancy.