Fast state verification

Unique input/output (UIO) sequences are used for state verification and functional test in finite state machines. A UIO sequence for a state s distinguishes it from other states in the FSM. Current algorithms to compute UIO sequences are limited in their applicability to FSMs with binary input symbols such as those found in control applications. Execution times of traditional approaches are exponential in the number of FSM inputs. We develop a new heuristic algorithm to generate UIO sequences for FSMs with binary inputs. Execution time is reduced significantly by reducing the size of the search space. When a UIO sequence cannot be generated, our algorithm generates a small number of functional faults for state verification.