Code and Data Placement for Embedded Processors with Scratchpad and Cache Memories

This paper proposes a code placement problem, its ILP formulation, and a heuristic algorithm for reducing the total energy consumption of embedded processor systems including a CPU core, on-chip and off-chip memories. Our approach exploits a non-cacheable memory region for an effective use of a cache memory and as a result, reduces the number of off-chip accesses. Our algorithm simultaneously finds a code layout for a cacheable region, a scratchpad region, and the other non-cacheable region of the address space so as to minimize the total energy consumption of the processor system. Experiments using a commercial embedded processor and an off-chip SDRAM demonstrate that our algorithm reduces the energy consumption of the processor system by 23% without any performance degradation compared to the best result achieved by the conventional approach.