Direct methods for synthesis of self-monitoring state machines

The authors consider synthesis methods that yield state assignments with checking invariants amenable to signature monitoring. They describe an automated synthesis approach based on a novel, generalized monitor architecture and prove that, for any given finite-state machine (FSM), a special, methodology-consistent state assignment exists. The state assignment permits each state´s reference signature to be extracted directly from the state code. This eliminates the need for explicit reference-signature storage and yields continuous monitoring with near zero error-detection latency at each state. A practical tool that implements these synthesis algorithms can, in 37 seconds, generate state assignments for all 41 MCNC synthesis benchmark FSMs. Layout overhead comparisons obtained with an FSM macro-cell CAD system show that this technique can require as little as 52.3% of traditional duplication´s layout area.<>