Graph representation of logic functions to design two-level MOS networks

Abstract

The design problem of two-level MOS networks with a minimum number of cells is reduced to the covering problem of graphs with a minimum number of cliques. When every node of the graph corresponds to a minterm, an algorithm which generates an MOS network with a minimum number of cells is presented. The time complexity of this algorithm is O(M)2, where M is the number of minterms. When every node of the graph corresponds to a prime implicant, a procedure which generates near optimum solutions by selecting prime implicants with special properties is presented. About 2 percent of designed networks for four-variable functions are not minimal ones.