Software-controlled cache architecture for energy efficiency

Power consumption is an important design issue of current multimedia embedded systems. Data caches consume a significant portion of total processor power for multimedia applications because they are data intensive. In an integrated multimedia system, the cache architecture cannot be tuned specifically for an application. Therefore, a significant amount of cache energy is actually wasted. In this paper, we propose the software-controlled cache architecture that improves the energy efficiency of the shared cache in an integrated multimedia system on an application-specific base. Data types in an application are allocated to different cache regions. On each access, only the allocated cache regions need to be activated. We test the effectiveness of the software-controlled cache of the MPEG-2 software decoder. The results show up to 40% of cache energy reduction on an ARM-like cache architecture without sacrificing performance.