27.6.5 Events

The RTC can generate the following output events:

• Overflow (OVF): Generated when the counter has reached its top value and wrapped to zero
• Tamper (TAMPER): Generated on detection of valid signal on a tamper input pin or tamper event input
• Compare (CMPn): Indicates a match between the counter value and the compare register
• Alarm (ALARMn): Indicates a match between the clock value and the alarm register
• Period n (PERn): The corresponding bit in the prescaler has toggled. Refer to Periodic Intervals for details.
• Periodic Daily (PERD): Generated when the COUNT/CLOCK has incremented at a fixed period of time

Setting the Event Output bit in the Event Control Register (EVCTRL.xxxEO = 1) enables the corresponding output event. Writing a zero to this bit disables the corresponding output event. Refer to the EVSYS - Event System for details on configuring the event system.

The RTC can take the following actions on an input event:

• Tamper (TAMPEVT): Capture the RTC counter to the timestamp register. See Tamper Detection.

Writing a ‘1’ to an Event Input Enable bit ((EVCTRL.TAMPEVEI) ) into the Event Control register (EVCTRL) enables the action on input events. Writing a ‘0’ to this bit disables the action on input events.