Reset and partial-reset-based functional broadside tests

摘要

Functional broadside tests were defined to avoid overtesting that may occur under scan-based tests because of non-functional operation conditions created by unreachable scan-in states. Functional broadside tests were computed assuming that functional operation starts after the circuit is initialised by applying a synchronising sequence. This study discusses the definition of functional broadside tests for the case where hardware reset is used for bringing the circuit into a known state before functional operation starts. This study shows that the set of reachable states for a circuit with hardware reset contains the set of reachable states based on a synchronising sequence. Consequently, the set of functional broadside tests and the set of detectable faults for a circuit with hardware reset contain those obtained based on a synchronising sequence. In addition, there are differences between different reset states in the sets of reachable states and the sets of detectable faults. This study also discusses the case where hardware reset is provided only for a subset of the state variables (referred to as partial reset).