Method for fault detection in safety mechanisms

Abstract

Safety mechanisms are embedded into a System on a Chip (SoC) and are operable to detect faults present in the logic circuitry in the SoC. Various types of faults in logic circuitry can occur, for example, a bit stuck at 0 or 1, or a transient or temporary fault due to radiation impacting the SoC. SoC devices are required to meet certain automotive safety integrity standards. The most stringent automotive safety integrity level requires that 90% of random latent faults are detected in all relevant logic, including all safety mechanism. Examples disclosed include hardware based checkers and hardware or software based pattern generation methods that achieve high online fault coverage in safety mechanism circuitry used for functional safety. A hardware based safety mechanism monitors the logic circuitry during operation. Any time the safety mechanism detects any faults in the logic circuitry, a fault notification is propagated to upstream logic.