Parallel approach to the functional decomposition of logical functions using developmental genetic programming

Functional decomposition is the main step in the FPGA-oriented logic synthesis, where a function is decomposed into a set of functions, each of which must be simple enough to be implementable in one logic cell. This paper presents a method of searching for the best decomposition strategy for logical functions specified by cubes. The strategy is represented by a decision tree, where each node corresponds to a single decomposition step. In that way the multistage decomposition of complex logical functions may be specified. The tree evolves using the parallel developmental genetic programming. The goal of the evolution is to find a decomposition strategy for which the cost of FPGA implementation of a given function is minimal. Experimental results show that our approach gives significantly better results than other existing methods.