A low energy cache design for multimedia applications exploiting set access locality

An architectural technique is proposed to reduce power dissipation in conventional caches. Our technique is based on the observation of cache access locality: current access is likely to touch the same cache set including the tags as the last access. We show that considerable amount of power driving the cache tag and data banks can be saved if this cache access locality is fully exploited. This is achieved through buffering and accessing the last accessed cache set instead of driving the tag and data banks. Unlikely previous designs, our technique does not incur performance degradation. Experimental results carried out on 8 KB/16 KB/32 KB data and instruction caches have respectively shown 31%/35%/36% and 51%/58%/66% power savings.