A State Assignment Procedure for Asynchronous Sequential Circuits

This paper presents a new procedure for constructing nonuniversal shared-row internal state assignments for asynchronous sequential circuits. The method consists basically of establishing an initial code with the minimum number of variables required to distinguish the states. satisfactory assignment is obtained. State variables added in the expansion of an assignment are merely the EXCLUSIVE OR of state variables in the original assignment. This simple construction procedure terminates with a maximum of m+[m/2] state variables for a 2^m-row flow table.