Way Sharing Set Associative Cache Architecture

Abstract

In order to minimize the conflict miss rate, cache memories can be organized in set-associative manner. The downside of increasing the associativity is increase in the per access energy consumption. In conventional n-way set-associative caches, irrespective of the set-wise demand, each set has n cache ways at its disposal, but cache sets may exhibit non-uniform demand for these cache ways. Exploiting this property, we propose a novel cache architecture, called way sharing cache, wherein by allowing sharing of cache ways among a pair of cache sets, we obtain dynamic energy savings as high as 41% in DL1 cache with negligible performance penalty.