11.3.3.1.2 32.768 kHz Oscillator (OSC32K)
The 32.768 kHz oscillator is optimized for Ultra-Low Power (ULP) operation. Power consumption is decreased at the cost of reduced accuracy compared to an external crystal oscillator.
This oscillator provides a 1.024 kHz or 32.768 kHz clock for the Real-Time Counter (RTC), the Watchdog Timer (WDT), and the Brown-out Detector (BOD). Also, this oscillator can provide a 32.768 kHz clock to the Main Clock (CLK_MAIN).
For the start-up time of this oscillator, refer to the Electrical Characteristics section.