25.6.5 Events
The RTC can generate the following output events and can be used by the EVSYS module:
- Overflow (OVF) – Generated when the counter has reached its top value and wrapped to zero
- Tamper (TAMPER): Generated on detection of a 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, see Periodic Intervals from Related Links
- Periodic Daily (PERD) – Generated when the COUNT/CLOCK has incremented at a fixed period of time
- RTC Event (RTC_EVENT) – Generates specific external signal on the RTC EVENT I/O pin
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. See Event System (EVSYS) from Related Links for more details on configuring the event system.
- Tamper (TAMPEVT) – Capture the RTC counter to the timestamp register. See Tamper Detection from Related Links.
Writing a one to an Event Input bit into the Event Control register (EVCTRL.xxxEI) enables the corresponding action on input event. Writing a zero to this bit disables the corresponding action on input event.
RTC Event (RTC_EVENT) – Other than the above events, which are mapped to the EVSYS module, the following events can generate a specific external signal on the RTC EVENT I/O pin:
- 32 KHz clock
- Alarm pulse
- 1-second clock
These event signals are configured using CFGCON4.RTCEVENTSEL[1:0] bits.