BVA-NQSL: A Bio-Inspired Variation-Aware Nonvolatile Quaternary Spintronic Latch

Quaternary memory and logic circuits have been studied by researchers, as they can provide denser integrated circuits and subsequently lower area and power consumption via succinct interconnects. Using multithreshold gate-all-around carbon nanotube field-effect transistors and the nonvolatile feature of magnetic tunnel junctions (MTJs), this letter proposes a bio-inspired variation-aware nonvolatile quaternary latch (Qlatch). Nonvolatility allows the system to be completely powered off during the idle state to reduce standby power significantly without the need for extra component and data loss. Moreover, thanks to the bio-inspired structure of the Qlatch, and the fact that no sense amplifier is used in this circuit to read the MTJs, the Qlatch is more robust to process variations. Simulation results show that the nonvolatile Qlatch consumes 7% less dynamic power and 12% less static power than the conventional Qlatch, has a 61% lower delay, and has 68% lower power delay product.