A CAD Tool for the Optimal State Assignment of Sequential Synchronous Circuits

Assigning proper binary codes to the states of sequential circuits is a long studied problem known as state assignment. The choice of the numbers assigned to the states determines the final hardware structure and implementation requirements of the circuits. Conventional state assignment techniques can not be applied when arbitrary optimality criteria are defined. The problem can actually be seen as a search problem with a huge non-linear space. The nature of the space makes it impossible to find optimal solutions by conducting exhaustive, random or conventional search techniques. In this paper, a CAD tool is introduced which solves the problem for sequential synchronous circuits by means of a Genetic Algorithm (GA). The main advantage of the tool is the ability to cope with large circuits and optimize with respect to different objective functions. Moreover, it is free, easy-to-use and crossplatform.