Design of a Sextuple Cross-Coupled SRAM Cell with Optimized Access Operations for Highly Reliable Terrestrial Applications

Abstract

The Aggressive technology scaling makes modern advanced SRAMs more and more sensitive to soft errors that include single-node upsets (SNUs) and double-node upsets (DNUs). This paper presents a novel Sextuple Cross-Coupled SRAM cell, namely SCCS cell, which can tolerate both SNUs and DNUs. The cell mainly consists of six cross-coupled input-split inverters, constructing a large error-interceptive feedback loop to robustly retain stored values. Since the cell has many redundant storage nodes, the cell achieves the following robustness: (1) the cell can self-recover from all possible SNU; (2) the cell can self-recover from partial DNUs; (3) the cell can avoid the occurrence of other DNUs due to node-separation. Simulation results validate the excellent robustness of the proposed cell. Moreover, compared with the state-of-the-art typical existing hardened cells, the proposed cell achieves an approximate 61% read access time as well as 12% write access time reduction at the costs of 47% power dissipation as well as 44% silicon area on average.