Reducing energy consumption of video memory by bit-width compression

A new architectural technique to reduce energy dissipation of video memory is proposed. Unlike existing approaches, the technique exploits the pixel correlation in video sequences, dynamically adjusting the memory bit-width to the number of bits changed per pixel. Instead of treating the data bits independently, we group the most significant bits together, activating the corresponding group of bit-lines adaptively to data variation. The method is not restricted to the specific bit-patterns nor depends on the storage phase. It works equally well on read and write accesses, as well as during precharging. Simulation results show that using this method we can reduce the total energy consumption of video memory by 20% without affecting the picture quality.