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 approach that employs a judicious mix of probability theory, circuit simulation, graph theory, and fault simulation. SERA achieves five orders of magnitude speedup over Monte Carlo-based simulation approaches with less than 5% error. Dependence of the soft-error rate (SER) of combinational logic circuits on a supply voltage, clock period, latching window, circuit topology, and input vector is 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 are orders of magnitude greater than those of the LSBs and the MSBs. An increase of up to 25% in the SER for multiplier circuits of various sizes has been observed as technology scales from 0.18 to 0.13 mum