Reliability analysis of an on-chip watchdog for embedded systems exposed to radiation and EMI

Due to stringent constraints such as battery-powered, high-speed, low-voltage power supply and noise-exposed operation, safety-critical real-time embedded systems are often subject to transient faults originated from a large spectrum of noisy sources; among them, conducted and radiated Electromagnetic Interference (EMI). As the major consequence, the system´s reliability degrades. In this paper, we present the most recent results involving the reliability analysis of a hardware-based intellectual property (IP) core, namely Real-Time Operating System - Guardian (RTOS-G). This is an on-chip watchdog that monitors the RTOS´ activity in order to detect faults that corrupt tasks´ execution flow in embedded systems running preemptive RTOS. Experimental results based on the Plasma processor IP core running different test programs that exploit several RTOS resources have been developed. During test execution, the proposed system was aged by means of total ionizing dose (TID) radiation and then, exposed to radiated EMI according to the international standard IEC 62.132-2 (TEM Cell Test Method). The obtained results demonstrate the proposed approach provides higher fault coverage and reduced fault latency when compared to the native (software) fault detection mechanisms embedded in the kernel of the RTOS.