Redundant faults in TSC networks: definition and removal

When designing Totally Self-Checking (TSC) systems the user imposes a functional encoding methodology and a constrained synthesis for guaranteeing that each fault produces a detectable error with respect to the applied coding. Both aspects, functional methodology and synthesis constraints, are not always supported by automatic tools thus possibly leading to the presence of undetected faults. The paper presents a classification of redundant faults with respect to TSC circuits (TSC redundant faults), proposing a methodology for their removal to achieve a complete fault coverage.