Reliability Evaluation of Combinational Logic Circuits by Symbolic Simulation

This paper presents new algorithms for evaluating the reliability of fault-tolerant combinational logic circuits. In order to model the effects of multiple faults on circuit functionality, we use fault indicators as control variables. We use BDD-based symbolic simulation to avoid the explicit enumeration of faults. We present experimental results on fault-tolerant implementations of several mcnc benchmark circuits. They show that undetectable multiple faults have a large impact on the reliability of fault-tolerant circuits.