Preprint from Workshop Notes, International Workshop on Logic Synthesis (IWLS’97), Tahoe City, California, May 19-21, 1997 Multi-output Functional Decomposition with Exploitation of Don't Cares

Functional decomposition is an important technique in logic synthesis, especially for the design of lookup table based fpga architectures. We present a method for functional decomposition with a novel concept for the exploitation of don't cares thereby combining two essential goals: the minimization of the numbers of decomposition functions in the current decomposition step and the extraction of common subfunctions for multi-output Boolean functions. The exploitation of symmetries of Boolean functions plays an important role in our algorithm as a means to minimize the number of decomposition functions not only for the current decomposition step but also for the (recursive) decomposition algorithm as a whole. Experimental results prove the e ectiveness of our approach.