Low Power Asynchronous VLSI with NEM Relays

Benjamin Tang, Sunil Bhave, Rajit Manohar

CMOS technology scaling has reached a point where the circuit's static power is as high as the dynamic power. While further process scaling will only worsen leakage in transistors, it will benefit NEM relay technology. As asynchronous circuit design helps with dynamic power and NEM delays with static power, the use of NEM relays in asynchronous VLSI is ideal for low-power applications. In this paper, we present ways of combining both asynchronous and NEMS technologies and compare them with their CMOS counterpart. NEM relays can effectively implement not only QDI designs, but also bundled-data and power-gated circuits. We show in simulation that a 64-bit C-element, 32-bit PCHB AND, and 8-bit PCHB adder implemented with NEM relays can achieve over 16X, 25X and 1.7X better energy-efficiency respectively compared to CMOS in a 90nm technology.