Improved read/write assist mechanism for 10‐transistor static random access memory cell

Abstract

AbstractThis paper presents a robust low‐power 10T SRAM cell (RLP10T) with a novel read/write assist mechanism, improving both read static noise margin (RSNM) and write static noise margin (WSNM) simultaneously. To assess its relative strength, we compared the proposed cell with recently published SRAM cells such as WRE8T, 10T‐P1, HFBS10T, WALP11T, and SE11T in 16‐nm CMOS technology node. The RLP10T cell shows 3.55/1.07 times higher/lower RSNM compared to the WRE8T/WALP11T cell and offers at least 1.10 times higher WSNM. Due to the presence of three series‐connected transistors in its read path, which includes a strong pull‐down transistor, the proposed design shows 1.23 times shorter read delay (TRA) than that of 10T‐P1/HFBS10T cell. The proposed cell incurs a penalty of high write delay (TWA) due to its long write path. However, it exhibits the fourth (second)‐best read (write) power, attributed to its single‐ended structure and lower read (write) frequency. It also dissipates acceptable leakage power due to its single‐bitline structure and the presence of stacked transistors in its read path and pull‐down path of one of the inverters in the cell core. Subjected to the severe process, voltage, and temperature variations, the RLP10T cell offers at least 1.31/1.09/1.03 times lower variability in RSNM/WSNM/TRA at VDD = 0.7 V, at the cost of 1.22 times area overhead compared to the WRE8T cell.