Formalized methodology for data reuse: exploration for low-power hierarchical memory mappings

Efficient use of an optimized custom memory hierarchy to exploit temporal locality in the data accesses can have a very large impact on the power consumption in data dominated applications. In the past, experiments have demonstrated that this task is crucial in a complete low-power memory management methodology. But effective formalized techniques to deal with this specific task have not been addressed yet. In this paper, the surprisingly large design freedom available for the basic problem is explored in-depth and the outline of a systematic solution methodology is proposed. The efficiency of the methodology is illustrated on a real-life motion estimation application. The results obtained for this application show power reductions of about 85% for the memory subsystem compared to the case without a custom memory hierarchy. These large gains justify that data reuse and memory hierarchy decisions should be taken early in the design flow.