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

Abstract

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.

Combined Frame Memory Motion Compensation for Video Coding

“…Moshnyaga's works [1], [5] on motion estimation reported the presence of block-data whose content remain unchanged between the adjacent frames. These unchanged block-data are facilitated to eliminate frame memory writes and computations during the motion estimation.…”

“…1 Both designs are synthesized with the clock constrained at 50 MHz, which is more than enough to perform real-time decoding even for CIF frame size. The memory size of the CFMMC is 42.3% smaller then that of the PPFMMC.…”

“…The PPFM swaps the role of the reconstructed current frame memory and the reference frame memory upon the completion of each frame's motion compensation. As a result, the PPFM requires a memory size of two frames and often accounts for approximately half of the energy consumption in a video decoder [1].…”

A 122-mW Low-Power Multiresolution Spectrum-Sensing IC With Self-Deactivated Partial Swing Techniques

“…In [2], wordlines were dynamically gated using a data-transition-indicating bit (DTB) according to the data of a RAM. In [3], a sense amplifier (SA) and precharge blocks were inactivated using a bit-width compression method. However, these methods ignored the additional power dissipation in evaluating a DTB itself in a bit-cell array.…”

Analysis of memory access optimization for motion compensation frames in MPEG-4

“…However, still the frame buffer is consuming 40% of the total en ergy [1]. Moshnyaga [2]. [3] reported the presence of block data whose content remain unchanged between the adjacent frames.…”