Architectural Vulnerability Factor Estimation with Backwards Analysis

Single-Event-Upsets in synchronous register-based designs are a severe problem for safety-critical applications. Exact and detailed error rate estimations are needed to determine a system´s level of reliability. Available methods for estimation consider only special effects, use special reliability models or are computationally intensive. We present an innovative method that is able to calculate the architectural vulnerability factor (AVF)of any RT-level circuit description by applying time-reversed stimulus values. This method, which we call Backwards Analysis, considers all major masking effects (logic masking, information lifetime, timing derating, transitive masking) in a single algorithm and delivers results in several levels of detail from average AVF through sensitivity waveforms. The results show the critical parts and states of a design, which could be used for reliability assessment and selective hardening of the circuit to reach a target failure rate.