State assignments for non-normal asynchronous sequential circuits

There is a lack of procedures that can be used to find good internal state assignments for asynchronous sequential circuits operating in the non-normal mode. Presented here, are two generalized state assignments, which are functions only of the number of rows in a flow table. The suggested bounds for the generalized state assignments are m + [log₂m] and m + [m/2] internal state variables for a 2m-row flow table, where [ ] means next lowest integer . Both generalized state assignments produce group (linear) codes. The algorithms for generating these internal state assignments are easy and straight-forward to implement. It is shown that each of these state assignments satisfactorily encode certain classes of flow tables. Even though a general proof has not been found to show that these assignments were standard, worst-case situations have been constructed, and it has never been necessary to increase the suggested bounds. An internal state assignment procedure for obtaining non-standard or non-generalized state assignments is also presented. The internal state assignments, using the proposed method, are obtained in a systematic manner; and generally require fewer internal state variables than other procedures presently available --Abstract, page ii