Lifetime Enhancement of Non-Volatile Caches by Exploiting Dynamic Associativity Management Techniques

International audienceBy showcasing the attractive features like high density and low static power, the emerging Non-Volatile Memories (NVMs) have recently being accepted act as a prominent choice in the memory hierarchy, including caches. However, the limited write endurance with the write variation introduced by the applications and the existing cache management policies leads to an early breakdown of NVM cells, thus reducing the effective lifetime.This chapter presents efficient techniques to improve the lifetime by mitigating inter-set write variation. Our first technique: FSSRP partitions the cache into groups of sets called fellow groups. Each set has two logical parts: Normal and Reserve. Sets within the fellow group can use the reserve part of its fellow sets to distribute the uneven writes. The second technique: FSDRP, based on FSSRP, partitions the cache vertically into equal-sized windows and use a different window one at a time as a reserve part during the execution to disperse the writes uniformly. Experimental results using full system simulation show a significant reduction in inter-set write variation over the baseline and existing technique