For interrupts and events, failures can be detected using information about the time behavior of the system. The monitored signals can be either periodic or aperiodic.

For a typical closed loop control application, most of the critical events are periodic in nature and these periodic events can be monitored and incoherence in the events can be used for fault detection. A few places where online monitoring periodic interrupts and events can be employed include:

• Online monitoring of periodic occurrence of interrupts, for example, ePWM, ADC end-of-conversion (EOC), eCAP and eQEP interrupts
• Online monitoring of periodic events such as periodic generation of ADC start-of-conversion (SOC): ADC SOC signal can be used to generate an external interrupt (XINT) with the help of X-BAR. The occurrence of periodic interrupts can be monitored.

Monitoring of interrupts and events which are normally not expected during the correct operation can also be used to improve the diagnostic coverage (e.g. ECC correctable error interrupt).