A compare-and-write ferroelectric nonvolatile flip-flop for energy-harvesting applications

In this paper, a novel compare-and-write ferroelectric nonvolatile flip-flop is developed, which can be used in the checkpoint processor for energy-harvesting applications. It can make the processor nonvolatile, secure and instant recoverable from power failures. The behavior model of ferroelectric capacitor is set up to characterize its electrical property. An improved architecture of ferroelectric capacitor based flip-flop is proposed in which a compare-and-write block is used to decide if the state of ferroelectric capacitor should be changed. Thus, the presented architecture can prolong the lifetime of the ferroelectric capacitor by removing the unnecessary programming cycles. The design is implemented in HJTM 0.18 um CMOS process and simulation results show that the proposed ferroelectric nonvolatile flip-flop operates properly and reduces 40-80% programming cycles, which increases the lifetime of the ferroelectric capacitors effectively and expands its application in checkpoint processors for energy-harvesting area.