UNIVERSAL STATE ASSIGNMENTS FOR SYNTHESIS OF ASYNCHRONOUS SEQUENTIAL CIRCUITS.

One essential problem for syntheses of asynchronous sequential circuits is that of generating internal state assignments which permit critical race-free realization of a given flow table. This paper presents a new systematic procedure for constructing universal single transition time (STT) state assignments and shows that the procedure can give better upper bounds on the number of state variables required for realizing asynchronous normal flow tables than any known universal STT state assignments. It is further shown that the procedure can also be applied to improve the best known bounds for (2,1)-separating systems which are known to be less restricted universal assignments. The specific feature of the procedure is that two binary code vectors are assigned to each internal state.