Reducing energy dissipation of frame memory by adaptive bit-width compression

In this paper, we propose a new architectural technique to reduce energy dissipation of frame memory through adaptive bitwith compression. Unlike related approaches, the technique utilizes the fixed order of memory accesses and data correlation of video sequences by dynamically adjusting the memory bitwidth to the number of bits changed per pixel. Instead of treating data bits independently, we group the most significant bits together, activating the corresponding group of bit lines adaptively to data variation. The approach is not restricted to specific bit patterns, nor does it depend on the storage phase. It works equally well on read and write accesses, as well as during precharging. Simulations show that in using this method, we can reduce the total energy consumption of frame memory by 20% without affecting the picture quality. The implementation scheme is simple yet compact. Index Terms--Bit compression, frame memory, low-power design, video encoders.