Fault simulation of multiple faults in PLAs

A novel approach is presented to the problem of the simulation of multiple crosspoint faults in PLAs (programmable logic arrays). An efficient algorithm is presented that makes use of concepts derived from the critical path method. To reduce memory allocation, the technique makes use of the minimal information set needed for exact analysis. Results obtained on benchmark PLAs show that those multiple crosspoint faults which are undetectable by means of single-fault-oriented test vectors represent a nonnegligible fraction of all possible faults and should, therefore, be explicitly considered