The design and implementation of a low-overhead supply-gated SRAM

We report a virtual supply domain control technique for low-leakage SRAMs. This method encompasses cell-based sleep circuit tiling, sequentially regulated poweron/off, and flexible domain interfacing. The usual overhead associated with driving sleep transistors is significantly reduced by powering on/off gradually. Over 26Ox and 3x leakage reduction is observed in 65nm-technology hardware for hard and soft gating, respectively, including the leakage of control and drive circuits. Measured virtual domain power-on latency is compatible with high-frequency designs. © 2006 IEEE.