Enhancing Reliability of STT-MRAM Caches by Eliminating Read Disturbance Accumulation
This work addresses the critical reliability threat posed by accumulated read-disturb errors in STT-MRAM caches when unverified ECC-protected cache blocks are read in parallel. For the first time, this study formally characterizes the cumulative nature of such errors and proposes REAP-cache, a lightweight mechanism that completely eliminates read-disturb errors without compromising performance. By refining the ECC verification process, optimizing parallel read scheduling, and incorporating a proactive error prevention strategy, REAP-cache dramatically enhances system reliability—improving the cache’s mean time to failure (MTTF) by 171×—while incurring less than 1% area overhead and only a 2.7% energy penalty.