22.3.12 Internal Consistency Checks

The ERRCTRL has internal consistency checks and can detect several internal errors. In particular, the internal state registers are duplicated, and the duplicated copies are monitored continuously for any mismatch. If such an error is detected, the internal state is inconsistent and cannot be trusted, and a Machine Check Reset request is sent to the Reset Controller. The reset request will cause an immediate entry to a safe state. For more information, refer to the Reset Controller section.

As a consequence of the immediate Reset, all I/O pins will be floated, and any heartbeat will stop due to the Control A (ERRCTRL.CTRLA) register Reset.

The assumption is that a reset will clear whatever condition caused the internal error. If the error persists, the MCU will enter an endless reset sequence.