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 power-on/off, and flexible domain interfacing. The usual overhead associated with driving sleep transistors is significantly reduced by powering on/off gradually. Over 260x 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.