Permissible functions for multioutput components in combinational logic optimization
Yoshi Watanabe, Lisa M. Guerra, Robert K. Brayton · IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems · 1996
This paper is concerned with logic optimization of multilevel combinational logic circuits. In the light of theoretical work of the past years, where a circuit is modeled by a Boolean network in which each node implements a single-output Boolean function, we address how a concurrent optimization over multiple nodes or components can lead to further optimization compared to conventional minimization techniques. In particular, we provide a procedure for computing maximally compatible sets of permissible relations for multiple nodes. This is a generalization of the classical notion of a compatible set of permissible functions for a single node, where no method is known for correctly computing such a maximal set. We provide a method for computing the set correctly for the general case. Based on this, we develop and implement a procedure for optimizing multiple nodes concurrently. The proposed procedure has been implemented, and we present experimental results.