ApplicationSpecic Memory Management for Embedded Systems Using SoftwareControlled Caches

We propose a way to improve the performance of embed ded processors running dataintensive applications by allow ing software to allocate onchip memory on an application specic basis Onchip memory in the form of cache can be made to act like scratchpad memory via a novel hard ware mechanism which we call column caching Column caching enables dynamic cache partitioning in software by mapping data regions to a specied sets of cache columns or ways When a region of memory is exclusively mapped to an equivalent sized partition of cache column caching provides the same functionality and predictability as a ded icated scratchpad memory for timecritical parts of a real time application The ratio between scratchpad size and cache size can be easily and quickly varied for each applica tion or each task within an application Thus software has much ner software control of onchip memory providing the ability to dynamically tradeo performance for onchip memory 1