Power-performance optimal 64-bit carry-lookahead adders

Abstract

A circuit sizing tool that minimizes the delay under energy constraints has been developed using optimisation software, tabulated delay models and analytical energy models. The tool is used to generate energy-delay (E-D) tradeoff curves for selected high-performance 64-bit carry-lookahead adders. The optimisation indicates that the sparse radix-4 carry-lookahead adder with sparseness factor of 2 has optimal performance in the energy-delay space.