The OSC32KCTRL gathers controls for all 32KHz oscillators and provides clock sources to the Generic Clock Controller (GCLK), Real-Time Counter (RTC), and Watchdog Timer (WDT).
The available clock sources are: XOSC32K, OSC32K, and OSCULP32K.
The OSC32KCTRL bus clock (CLK_OSC32KCTRL_APB) can be enabled and disabled in the Main Clock module (MCLK).