Switch-level bridging fault simulation in the presence of feedbacks

This paper investigates the degradation in detectability of bridging faults caused by situations of active feedback and logically unresolvable intermediate values under different fault modeling assumptions. A bridging fault simulator is presented that is based on a combination of switch-level modeling and levelized logic simulation. Levelized simulation is efficient for fault propagation and feedback analysis, whereas the switch-level model is used for determining whether an intermediate value is logically resolvable. A method to extract the logic function of channel graphs is presented in order to perform levelized processing of switch-level networks. The experimental results show that active feedback may reduce fault coverage by as much as 9% for stuck-at test sets and realistic bridging fault sets.