An automatic Scratch Pad Memory management tool and MPEG-4 encoder case study

Using software-controlled scratch-pad memory (SPM) in systems-on-chip has the potential of reducing power consumption by using design-time application knowledge to reduce memory accesses and processor stalls. This paper presents a fully automatic application analysis and transformation tool which selects data-structures for transfer to the SPM and schedules data transfers between background memory and SPM (pre-fetching) to achieve both high performance and low power consumption. A case study applying this tool on an MPEG-4 video encoder shows an overall power reduction of 25%, a 40% power reduction in just the memories and a 40% reduction in processor cycles as compared to an optimized hardware-cache based solution.