A fast algorithm for OR-AND-OR synthesis

Design methods for OR-AND-OR three-level networks are useful for exploiting the flexibility of logic blocks in many complex programmable logic devices. This paper presents T RIMIN, a fast heuristic algorithm for designing OR-AND-OR networks from sum-of-products expressions. Each output of the network realizes a sum-of-complex-terms expression, where a complex term (CT) is similar to a product-of-sums expression. TRIMIN ʹs objective is to lower the number of gates in the network. It first generates a set of CTs by applying factorization techniques; then, it solves a set-covering problem by using a greedy algorithm to select a subset of the CTs. The effectiveness of TRIMIN is demonstrated through experimental results.