Modern hand-held multimedia terminals consume significant power for their quality display devices. Due to 60Hz or higher LCD refresh operations, frame buffer memory and related buses become dominant power consumers. In this paper, we introduce an efficient frame buffer compression scheme that uses differential Huffman coding and its hardware implementation. The compression and decompression must be simple and not incur distinct power overhead involving no CPU operations. We have achieved both on-the-fly compression and high compression efficiency devising a limited-size code book, color-difference reduction techniques and an adaptive code book update scheme. On the MobileMark 2002 benchmark, our techniques reduce the frame buffer activity by 52% to 90%, saving up to 86mW including the overhead.
['Hojun Shim', 'Youngjin Cho', 'Naehyuck Chang']
Frame buffer compression using a limited-size code book for low-power display systems