An Examination of the Cost Function for Programmable Logic Arrays

Abstract

Cost functions for combinational switching circuits are commonly defined as monotonically increasing functions of the number of gates and the number of inputs. The structure of programmable logic arrays (PLA's) is such that the cost is more aptly only dependent on gate quantity. The consequences of redefining cost for PLA's are studied with respect to covering algorithms. The major benefits are that a multiple output prime implicant (implicate) table can be viewed as a single output table and that minimal covers can be determined much more simply, especially for cyclic tables.