Multi-level Logic Optimization Based on Wave Synthesis of Permissible Mutation Functions (WASP)

WAve Synthesis of Permissible mutation functions, WASP, is a heuristic with an objective to minimize the nodes and the levels of an acyclic multiple level boolean network of 2-input nodes. WASP transforms a multi-input, multi-output perturbation region of wires Pj into a single-level mutation subcircuit Mj and a remainder subcircuit Rj . The transformations include the concept of minimum cost permissible mutation subcircuit Mj , formed by replacing each pair of wires that are perturbable by a set of 255 mutation functions. Since we can precompute and store all possible 2-1 perturbation indices that map into 255 mutation indices (ranked into 8 equivalent cost classes), we can determine the minimum cost mutation by a simple table look-up, given the 4-tuple of permissible perturbation indices. Unlike methods that rely on truth tables or ROBDDs, the methods proposed here can exploit e cient ATPG techniques and can thus more rapidly scale to circuits with the larger number of inputs.