Test generation for combinational circuits with multiple faults

A test generated under the single-fault assumption may be invalid for the combinational circuit with multiple faults because of masking among them. The authors propose a new test generation algorithm for combinational circuits with multiple faults. A property of a valid test which can detect a target fault regardless of the presence of any other fault is studied and it is shown that a pair of input vectors is necessary for the valid test of a target fault. Next, an algorithm for generating a single sensitized path using a seven-valued calculus and a decision algorithm for finding a completely single sensitized path are presented. Finally, experimental results on several benchmark circuits are given