A novel charge recycle read write assist technique for energy efficient and fast 20 nm 8T-SRAM array

The read instability of conventional 6T-SRAM cell has made the 8T-SRAM cell a substitute for high data reliability. But the single ended nature of read operation demands a complete Vdd swing of high capacitive read bit lines leading to large energy consumption. A novel assist technique using charge recycling concept is proposed here which reduces the read and write energy by reducing the voltage swing. Mathematical analysis of the proposed technique, theoretically predicts the read and write energy to reduce by 75% and 25% respectively compare to that of the conventional 8T-SRAM array. Experimental simulation using predictive technology model demonstrates these two energy consumptions to be reduced by 58% and 27% respectively. The proposed technique also reduces the leakage current flow in the standby cells and hence the energy consumption. The dummy read current flow in the half-selected cells is also controlled significantly in the proposed technique. The stability of the SRAM cell remains unchanged by the insertion of the proposed assist technique.