On Boolean functions having maximal number of subfunction classes

Advances in LSI technology have led to problems concerning the selection of output functions for optimum complex logic modules. A natural criterion for the evaluation of possible designs is the structure of the set of all subfunctions of the function realized by a module. Thus studying properties of the sub-function sets of Boolean functions is an approach to solving the above problems. In the paper some general results on Boolean functions having the largest sets of subfunction classes are presented and methods for constructing such functions are discussed.