Multiple stuck-at fault diagnosis in combinational circuits based on restricted single sensitized paths

We describe a method for multiple stuck-at fault diagnosis in combinational circuits based on restricted single sensitized paths generated by a seven-valued calculus. Our method determines the set of all possible stuck-at faults from the faulty response observed at the primary output, based on deducing internal values along the sensitized path. By using the fault-free response observed at the primary output, we remove fault-free lines along the sensitized path from the set of the candidates, by checking whether the fault-free response is prevented by the candidate fault from propagating to the primary output regardless of the presence of any other candidates. Experimental results on the benchmark circuits show that the fault locations are identified within 2-25% of all stuck-at 0 and 1 faults on all lines in the circuit with up to fourfold multiple faults without probing internal lines