A fine-grain dynamic sleep control scheme in MIPS R3000

Abstract

A fine-grain dynamic power gating is proposed for saving the leakage power in MIPS R3000 by sleep control and applied to a processor pipeline. An execution unit is divided into four small units: multiplier, divider, shifter and other (CLU). The power of each unit is cut off dynamically, based on the operation. We tape-outed the prototype chip Geyser-0, which provides an R3000 Core with the power reduction technique, 16 KB caches and translation lookaside buffer (TLB) using 90 nm CMOS technology. The evaluation results of four benchmark programs for embedded applications show that 47% of the leakage power is reduced on average with 41% area overhead.