A Set Associative Cache Model with Energy Saving

This paper proposes a method to save energy in set associative cache. The method gathers the time of access of each memory address by profiling. Additional information about next access to a way is maintained in the cache ways. All the ways of the cache are put in either disable mode or low energy mode as supported by the cache. At each time unit, the cache ways are searched enabling the way that is going to be accessed next. If no way is going to be accessed in the next time unit, the generated address is placed respecting the replacement algorithm in the cache using the address mapping function. During this mapping all the ways of the mapped set are enabled as in a traditional set associative cache. The model was simulated on SPEC2 000 benchmarks with average energy savings of 19% and performance degradation of about 10%.