Enhancing the multiple-fault detection of single-fault test sets

Abstract

The paper discusses the problem of deriving single-fault test sets (SFTS) with an improved multiple-fault detection ability for combinational ciruits. Two heuristics for deriving SFTSs are given for the avoidance of fault masking. Then, a special class of single-fault vectors that satisfies both the heuristics is defined and derived using the Boolean difference approach. It is shown that, if a certain condition is satisfied, a fault can be detected without any fault masking. Even when the condition is not met, the protection against fault masking is still quite high. With this method, SFTs with an improved multiple-fault detection ability can easily be obtained without any additional cost.