Analysis and implementation of fault simulation techniques concerning automotive functional safety using Cadence Legato

Abstract

Mixed-signal electronic systems are increasingly being used in safety-critical applications such as automotive, aerospace, and industrial automation. However, ensuring their functional safety remains a major challenge due to the lack of a standardized methodology for performing failure and safety analysis, particularly at the transistor level where analog and digital domains interact closely.

To address this gap, a fault injection and simulation methodology was developed using the Cadence Legato platform. This approach aims to establish an easy to adopt, scalable and accurate fault analysis flow specifically tailored for mixed-signal circuits. A comprehensive set of fault permutations—including both transient and permanent faults—was injected into a representative test circuit to evaluate the robustness and safety behavior of the design under various fault conditions. The simulation results provided key safety relevant metrics such as fault detection coverage, safe fault tolerance, and latent fault susceptibility. In ddition, the flow helped to identify critical areas in the design that were most vulnerable to faults,offering deep insights into potential failure modes. These findings demonstrate the practicality and effectiveness of the proposed methodology in supporting functional safety assessments for mixed-signal designs. Overall, this work contributes a structured, transistor-level fault analysis framework that can serve as a foundation for standardizing functional safety verification in mixed-signal systems.