Multiple fault diagnosis in combinational circuits using sensitizing input‐pairs

Abstract

AbstractThis paper presents a new method for multiple fault diagnosis of combinational circuits using sensitizing input‐pairs. A partition of a circuit under test into subtree circuits and a generation method for diagnostic test are described. The set of diagnostic tests used in this paper is one of sensitizing input‐pairs that generate sensitizing paths including checkpoints on them.By studying the relation between a sensitizing path generated by a sensitizing input‐pair and a subtree circuit, a method is presented for multiple fault diagnosis in the subtree circuit based on the fault‐free and the faulty responses observed at primary outputs. A deduction algorithm is described for a value at an output of a subtree circuit which does not have a primary output. The proposed method is applied to benchmark circuits having double faults, triple faults, and fourfold faults. Experimental results show that suspected faults are identified within 8 to 30 percent of all stuck‐at 0 and 1 faults on all lines in the circuit.