Logic Masking for SET Mitigation Using Approximate Logic Circuits

Logic masking approaches for Single-Event Transient (SET) mitigation use hardware redundancy to mask the propagation of SET effects. Conventional techniques, such as Triple-Modular Redundancy (TMR), can guarantee full fault coverage, but they also introduce very large overheads. Alternatively, approximate logic circuits can provide the necessary flexibility to find an optimal balance between error coverage and overheads. In this work, we propose a new approach to build approximate logic circuits driven by testability estimations. Using the concept of unate functions, approximations are performed in lines with low testability in order to minimize the impact on error coverage. The proposed approach is scalable and can provide a variety of solutions for different trade-offs between error coverage and overheads.