Non-Volatile Flip-Flop Based on Unipolar ReRAM for Power-Down Applications

In this paper, we propose a new architecture of non-volatile Flip-Flop based on ReRAM unipolar resistive memory element (RNVFF). This architecture is proposed in the context of power-down applications. Flip-Flop content is saved into ReRAM memory cell before power-down and restored after power-up. To simulate such a structure a compact model of unipolar ReRAM was developed and calibrated on best in class literature data. The architecture of the RNVFF, based on the insertion of a non-volatile memory block before a master-slave Flip-Flop, is detailed. The save and restore processes are described from the succession of four operating modes (normal, save, read, reset) needed by the save and restore processes. Finally, the structure is fully validated through electrical simulations, when the data to save is either ‘0’ or ‘1’.