Code compression for low power embedded system design

Abstract

We propose instruction code compression as an efficient method for reducing power on an embedded system. Our approach is the first one to measure and optimize the power consumption of a complete SOC (System--On--a--Chip) comprising a CPU, instruction cache, data cache, main memory, data buses and address bus through code compression. We compare the pre-cache architecture (decompressor between main memory and cache) to a novel post-cache architecture (decompressor between cache and CPU). Our simulations and synthesis results show that our methodology results in large energy savings between 22% and 82% compared to the same system without code compression. Furthermore, we demonstrate that power savings come with reduced chip area and the same or even improved performance.