CQCTL: A Cost-Optimized and Quadruple-Node-Upset Completely Tolerant Latch Design for Safety-Critical Applications

With the rapid development of semiconductor technologies, latches are becoming increasingly sensitive to multiple node upsets, such as triple node upsets and quadruple node upsets (QNUs). Therefore, they should be considered for safety-critical applications. To effectively tolerate QNUs, this paper proposes a QNU-tolerant latch design with moderate overhead. The latch mainly comprises two parallel storage cells, and three 2-input C-elements. When any four internal nodes are flipped at the same time, the output value of the latch will not be affected. Simulation results not only confirm the QNU tolerance of the proposed latch but also demonstrate that the latch can reduce by 40.93% delay, 40.73% area, 13.11% power, and 71.19% delay-area-power product (DAPP) on average compared to the existing QNU-tolerant latches.