Functional extension of structural logic optimization techniques

This work provides a generalization of structural logic optimization methods to general Boolean networks. With this generalization, the nodes of the network are no longer restricted to simple gates and can be functions of any size. Within this framework, we present necessary and sufficient conditions to identify all the possible functional expansions of a node that allow one to eliminate a wire elsewhere in the network. These conditions are also given for the case of multiple variable expansion, providing an incremental mechanism to perform functional transformations involving any number of variables that can be applied in a very efficient manner. On the other band, we will show in this paper that relevant simplifications can be obtained when this framework is applied to the particular case of AND-OR-NOT networks, resulting in important savings in the computational effort. When compared to previous approaches, the experimental results show an important reduction in the number of computations required.