Accurate modeling and fault simulation of Byzantine resistive bridges

Many recent studies show that a resistive bridging fault may cause intermediate voltages at the bridging fault site. Since the gates in the fanout of the fault site may have distinct and multiple logic threshold voltages, namely VIL and VIH, these gates may interpret the intermediate voltage as logic '1', logic '0', or logically indeterminate. Such fault behavior is described as the bridging fault Byzantine general problem (T. Nanya et al., Nov. 1989). None of the existing models of bridging faults used by bridging fault simulators accurately captures the indeterminate logic behavior of such bridges. We present a resistive bridging fault model that accurately yet efficiently captures indeterminate logic values. We also describe an efficient PPSFP bridging fault simulator and show that all previous approaches seriously overestimate bridging fault coverage.