Test generation for primitive path delay faults in combinational circuits

Abstract

This paper presents a method of identifying primitive path-delay faults in combinational circuits, and deriving robust tests for all robustly testable primitive faults. It uses the concept of sensitizing cubes to reduce the search space. This approach helps identify faults that cannot be part of any primitive fault, and avoids attempting test generation for them. Sensitization conditions determined for primitive fault identification are also used in test generation, reducing test generation effort. Experimental results on some of the ISCAS'85 and MCNC'91 benchmark circuits indicate that they contain a fair number of primitive multiple path delay faults which must be tested.