0.5-V operation variation-aware word-enhancing cache architecture using 7T/14T hybrid SRAM

This paper presents a novel cache architecture using 7T/14T hybrid SRAM, which can dynamically improve its reliability with control lines. Our proposed 14T word-enhancing scheme can enhance its operating margin in word granularity by combining two words in a low-voltage mode. The proposed scheme is suitable for dynamic voltage and frequency scaling (DVFS). In a 65-nm process, it can reduce the minimum operation voltage (Vmin) to 0.5 V, which is 42% and 21% lower, respectively, than the conventional 6T SRAM and the cache word-disable scheme. The respective power reductions are 90% and 65%.