SYMBOLIC METHOD FOR SIMPLIFYING AND-EXOR REPRESENTATIONS OF BOOLEAN FUNCTIONS USING A BINARY-DECISION TECHNIQUE AND A GENETIC ALGORITHM

An algorithm called XORGA is presented which minimises Boolean multi-o utput logic functions as multilevel AND-EXOR networks of two-input log ic gates. It carries out symbolic simplification, and works from the b ottom of a binary variable decision tree to the top, with variable cho ice determined using a genetic algorithm. Since the algorithm is multi level in nature, it delivers more compact circuits than two-level ESOP minimisation algorithms, such as EXMIN2. It also finds more economica l representations than the fixed polarity Reed-Muller method.