  Non-volatile flip-flops (NVFFs) using power gating techniques promise to
overcome the soaring leakage power consumption issue with the scaling of CMOS
technology. Magnetic tunnel junction (MTJ) is a good candidate for constructing
the NVFF thanks to its low power, high speed, good CMOS compatibility, etc. In
this paper, we propose a novel magnetic NVFF based on an emerging memory device
called NAND-SPIN. The data writing of NAND-SPIN is achieved by successively
applying two unidirectional currents, which respectively generate the spin
orbit torque (SOT) and spin transfer torque (STT) for erase and programming
operations. This characteristic allows us to design an erase-hidden and
drivability-improved magnetic NVFF. Furthermore, more design flexibility could
be obtained since the backup operation of the proposed NVFF is not limited by
the inherent slave latch. Simulation results show that our proposed NVFF
achieves performance improvement in terms of power, delay and area, compared
with conventional slave-latch-driven SOT-NVFF designs.
