Searching for Better Logic Circuits: Using Artificial Intelligence Techniques to Automate Digital Design.

Abstract

Logic circuits are at the core of modern computing. The process of designing circuits which are efficient is thus of critical importance. Usually, logic circuits are designed by human beings who have a specific repertoire of conventional design techniques. These techniques limit the solutions that may be considered during the design process in both form and quality. The limits guide designers through the immense realm of possible circuits, thus making the problem more manageable. Simultaneously, the limits sometimes eliminate from consideration circuits which are optimal in terms of size, depth, etc. By exploring the full range of possible solutions, circuits could be discovered which are superior to the best known human designs. Automated design techniques borrowed from artificial intelligence have allowed exactly that. Specifically, the application of genetic algorithms has allowed the creation of circuits which are substantially superior to the best known human designs. This paper expands on such previous research with a three-fold approach. This approach is comprised of (1) two distinct optimizations for the application of genetic algorithms to design, (2) the formulation and implementation of a systematic search technique to the problem and (3) a comparison of the relative merits of the optimized genetic algorithm and the systematic search technique. It is contended that both genetic algorithms and systematic search can be preferable depending on the situation at hand.