Magnetic nonvolatile flip-flops with spin-Hall assistance for power gating in ternary systems

In this paper, two ternary nonvolatile magnetic flip-flops are proposed to provide power gating in ternary systems. The proposed designs sequence ternary data in ternary data paths in their normal function. Furthermore, they can backup and restore the data of a ternary system before and after power gating. The proposed designs rely on assistance from the spin-Hall effect for the data backup operation, which eliminates the incubation delay. This method also needs no extra supply voltages higher than the nominal voltage of the technology. Furthermore, sub-10-nm gate-all-around carbon nanotube field-effect transistors (GAA-CNTFETs) are utilized to design the flip-flops and the required control switches. In the proposed ternary flip-flops, dual flat-band voltages are used for the GAA-CNTFET to determine the required switching thresholds, which is more feasible than the use of different diameters for the nanotubes. It is notable that the contention-free write operation and the disturbance-free read operation of the proposed design enhance its performance and robustness. Monte Carlo simulations certify the correct function and acceptable robustness of the proposed designs in the presence of various process variations.