A ReRAM-based single-NVM nonvolatile flip-flop with reduced stress-time and write-power against wide distribution in write-time by using self-write-termination scheme for nonvolatile processors in IoT era

Recent nonvolatile flip-flops (nvFFs) enable the parallel movement of data locally between flip-flops (FFs) and nonvolatile memory (NVM) devices for faster system power off/on operations. The wide distribution and long period in NVM-write times of previous two-NVM-based nvFFs result in excessive store energy (Es) and over-write induced reliability degradation for NVM-write operations. This work proposes an nvFF using a single NVM (1R) with self-write-termination (SWT), capable of reducing ES by 27+x and avoid over-write operations. In fabricated 65nm ReRAM nvProcessor testchips, the proposed SWT1R nvFFs achieved off/on operations with a 99% reduction in Es and 2.7ns SWT latency (TSWT). For the first time, an nvFF with single NVM device is presented.