A Method to Reduce Power Dissipation of Conditional Operations with Execution Probabilities and its Application to Dual Supply Voltage System

摘要

条件依存処理は投機的演算実行により処理実行時間を短縮できるが、結果的に不要となる演算実行によって電力が消費される。演算の実行確率を考慮して投機的に実行する演算を選択することで消費電力を削減する手法を提案する。また、高低二種類の電源電圧を使用する回路において演算器数および実行時間の上限が与えられたとき、電源電圧割り当てを考慮して消費電力を最小化する問題への応用を示す。%In processing with conditional operations, computations are executed conditionally based on the result of condi­tion operation. The scheduling method is proposed to reduce the energy dissipated unnecessarily by the speculative operations considering the probability of operation execution. Executing computation with low power supply voltage reduces the energy dissipation but requires more control steps for computations. The scheduling method is applied to select power supply volt­ages to minimize the energy dissipation for processing with conditional operations with a processing speed requirement. The experimental results show 15% to more than 30% energy can be reduced with the proposed method.