Resistive bridge fault modeling, simulation and test generation

In this work¹ we develop models of resistive bridging faults and study the fault coverage on ISCAS85 circuits of different test sets using resistive and zero-ohm bridges at different supply voltages. These results explain several previously observed anomalous behaviors. In order to serve as a reference, we have developed the first resistive bridging fault ATPG, which attempts to detect the maximum possible bridging resistance at each fault site. We compare the results of the ATPG to the coverage obtained from other test sets, and coverage obtained by using the ATPG in a clean-up mode. Results on ISCAS85 circuits show that stuck-at test sets do quite well, but that the ATPG can still improve the coverage. We have also found that the loss of fault coverage is predominantly due to undetected faults, rather than faults in which only a small resistance is detected. This suggests that lower-cost fault models can be used to obtain high resistive bridge fault coverage