Extended addressing mode for low power

This paper demonstrates the feasibility of a register-memory addressing mode in microprocessors targeted for low power applications. Using a high level power profiling tool that performs software energy evaluation, the major sources of power dissipation in a typical RISC processor are identified. It is shown that the addition of a register-memory addressing mode can target these `hot-spots' and provide power savings. Two different implementation options are considered and the power-performance trade-offs are evaluated. The reduction in performance is cushioned by the reduced instruction count, and it is anticipated that the overall impact on the total execution time of programs will be acceptable in low power application domains.