Skip to Main Content
Three-level logic is shown to have a potential for reducing the area over two-level implementations, as well as for a gain in speed over multilevel implementations. A heuristic algorithm TOP is presented, targeting a three-level logic expression of type g1°g2, where g1 and g2 are sum-of-products expressions and '°' is a binary operation. For the first time, to the authors' knowledge, this problem is addressed for an arbitrary operation '°', although several algorithms for specified cases of '°' have been presented in the past. The experimental results show that, on average, the total number of product-terms in the expression obtained by TOP is about one third of the number of product-terms in the expression obtained by a two-level AND-OR minimiser.