Cycle-time-aware sequential way-access set-associative cache for low energy consumption

In this paper, we exploit the concept of sequential way access to reduce the number of ways being activated on each access of set-associative cache for low energy consumption while maintaining performance. The proposed architecture accesses each way in sequence, and then eliminates subsequent accesses if a hit is detected. It features smart cache placement and replacement policies to minimize the number of required access cycles. It can also reduce the heavy fanout load of the hit-signal, which suppresses the possible increase of cache cycle time due to more complicated cache control mechanism. The experimental results show that a 32 KB 2-way sequential way-access set-associative cache reduces the energy consumption by 24% compared against a conventional 2-way set-associative cache with the same size at virtually no performance loss.