Circuit optimization using carry-save-adder cells

Carry-save-adder (CSA) is the most often used type of operation in implementing a fast computation of arithmetics of register-transfer-level design in industry. This paper establishes a relationship between the properties of arithmetic computations and several optimizing transformations using CSAs to derive consistently better qualities of results than those of manual implementations. In particular, we introduce two important concepts, operation duplication and operation split, which are the main driving techniques of our algorithm for achieving an extensive utilization of CSAs. Experimental results from a set of typical arithmetic computations found in industry designs indicate that automating CSA optimization with our algorithm produces designs with up to 53% faster timing and up to 42% smaller area.