Low-Overhead State-Retaining Elements for Low-Leakage MTCMOS Design

Multi-threshold CMOS (MTCMOS) has shown to be a very effective technique for reducing sub-threshold leakage currents in DSM CMOS designs. Application of the MTC-MOS paradigm to sequential circuits requires the availability of data-retaining elements for storing circuit state during stand-by mode. In this paper we propose two novel circuit schemes for sequential elements featuring low leakage currents in stand-by mode and high-speed/low-dynamic power in active mode. We present post-layout simulation results obtained after parasitic extraction for delay and power of circuits built in 130nm CMOS technology. Our experiments demonstrate several advantages of the proposed schemes over the best previously published solutions.