Inquisitive Defect Cache: A Means of Combating Manufacturing Induced Process Variation

This paper proposes a new fault tolerant cache organization capable of dynamically mapping the in-use defective locations in a processor cache to an auxiliary parallel memory, creating a defect-free view of the cache for the processor. While voltage scaling has a super-linear effect on reducing power, it exponentially increases the defect rate in memory. The ability of the proposed cache organization to tolerate a large number of defects makes it a perfect candidate for voltage-scalable architectures, especially in smaller geometries where manufacturing induced process variation (MIPV) is expected to rapidly increase. The introduced fault tolerant architecture consumes little energy and area overhead, but enables the system to operate correctly and boosts the system performance close to a defect-free system. Power savings of over 40% is reported on standard benchmarks while the performance degradation is maintained below 1%.