A soft error rate analysis (SERA) methodology

We present a soft error rate analysis (SERA) methodology for combinational and memory circuits. SERA is based on a modeling and analysis-based approach that employs a judicious mix of probability theory, circuit simulation, graph theory and fault simulation. SERA achieves five orders of magnitude speed-up over Monte Carlo based simulation approaches with less than 5% error. Dependence of soft error rate (SER) of combinational circuits on supply voltage, clock period, latching window, circuit topology, and input vector values are explicitly captured and studied for a typical 0.18 mum CMOS process. Results show that the SER of logic is a much stronger function of timing parameters than the supply voltage. Also, an "SER peaking" phenomenon in multipliers is observed where the center bits have an SER that is orders of magnitude greater than that of LSBs and MSBs.