Clocks Startup

The device selects the OSC16M oscillator which is enabled by default after reset and configured at 4MHz.

This 4MHz clock is also the default time base for the Generic Clock Generator 0 which provides the main clock (CLK_MAIN) to the system through the GLCK_MAIN clock.
Note: Other generic clocks are disabled to optimize power consumption.

Some synchronous clocks require also to be active after startup.

Note: These active synchronous clocks also receive the 4MHz clock from Generic Clock Generator 0.

Refer to the Clock Mask Register section in the Main Clock (MCLK) chapter to obtain the list of clocks that are running by default.