Self-checking FSMs based on a constant distance state encoding

The design of self-checking systems is a viable approach for coping with critical applications, guaranteeing the on-line detection of a fault as soon as it causes an erroneous behavior. The aim of this paper is the definition of a design strategy for sequential circuits, starting from their description in terms of Finite State Machines. The attention is focused on a constant distance code and state encoding technique which provide, together with a traditional Berger encoding of the outputs, a self-checking system. Benchmark results and a comparison with other approaches are presented to evaluate the quality of the proposed methodology.