Arithmetic Data Path Optimization Using Borrow-Save Representation

Abstract

Considering the performance increase provided by redundant operators such as adders and multipliers, it appears interesting to generalize the use of those operators in high computational digital circuit design. Using redundant arithmetic in conjunction with classical arithmetic is nevertheless a complex task. Optimization CAD tools which automate its use become therefore very helpful. However the existing approaches are restricted in using only the Carry-Save representation. In this paper we propose to overcome this limitation with an exploration of the possible optimizations of using the Borrow-Save representation also. To illustrate this, the optimizations of a Distance Computation Unit (DCU) and a Discrete Cosine Transform (DCT) operators are presented.