31.5.1 12 MHz RC Oscillator

After reset, the 12 MHz RC oscillator is enabled and selected as the source of MAINCK and MCK. MCK is the default clock selected to start up the system.

Refer to the table “DC Characteristics”.

The software can disable or enable the 12 MHz RC oscillator with the MOSCRCEN bit in the Clock Generator Main Oscillator register (CKGR_MOR).

When disabling the Main clock by clearing CKGR_MOR.MOSCRCEN, PMC_SR.MOSCRCS is automatically cleared, indicating the Main clock is OFF.

Setting the MOSCRCS bit in the Power Management Controller Interrupt Enable register (PMC_IER) triggers an interrupt to the processor.