Run-time Active Leakage Reduction by power gating and reverse body biasing: An eNERGY vIEW

Abstract

Run-time active leakage reduction (RALR) is a recent technique and aims at aggressively reducing leakage power consumption. This paper studies the feasibility of RALR from the energy aspect, for both power gating (PG) and reverse body bias (RBB) implementations.We develop two energy saving models for PG and RBB, respectively. These models can accurately estimate the circuit energy saving at any time, even when the circuit is in state transition. In PG modeling, we discover a physical phenomenon called ldquoinstant savingrdquo, which can affect the model accuracy by 30%-50%. Based on the RBB model, we derive the optimum design point of RBB for RALR. Finally in terms of energy saving, we define four figures-of-merit, to compare the efficacy of using PG and RBB to implement RALR.