Soft-Error-Aware SRAM for Terrestrial Applications

Quadruple and Sextuple Cross-Coupled SRAM Cell Designs With Optimized Overhead for Reliable Applications

“…In order to quantify the various overhead of the proposed SCCS and QCCS cell and make a fair comparison with the state-of-the-art SRAM cells described in Section II, the same simulation conditions described in the above section were used for all simulations. The reliability and overhead comparison results among the unhardened/hardened SRAM cells in terms of SNU recoverability (SNUR), number of DNU Hardened node-Pairs (#DHP), read access time (RAT), write access time (WAT), average power dissipation (dynamic and static), silicon area measured as in [31] and sensitive cross-section area measured as in [35] are shown in Table I.…”

“…Based on the variation in output, the designer can decide to change the design. Foundry companies provide a model file for MC Simulation to know the fluctuation in output [35][36]. The µ and σ comparison of power loss and stability for SRAM cells are reported in Table II.…”

“…Also, to check the process, voltage, and temperature (PVT) variations on SNU and DNU of bit-cells, the MC simulation has been performed. Truncated Gaussian variation is applied to the widths, lengths, and threshold voltages of all-transistor with ±3σ variation to perform 5000 MC simulations [35]. Meanwhile, the probability of SNU occurrence (PS) of the cells is calculated as the ratio of the sensitive area of a cell to the total area of the cell [36].…”

“…Furthermore, the robustness of SNU/DNU recovery is assessed by evaluating the probability of logical flipping (PLF). It is calculated as the ratio of simulations fail to recover to the total number of simulations (5000) [35]. The PLF comparison of considered cells is reported in Table III.…”

“…To evaluate the impact of gate length and threshold voltage Vth change on Qc, a simple empirical model from Ref. [35] is used. The time effectiveness of the model makes it suitable for circuit-level design exploration and tool implementation.…”