If the Clock Failure Detection Source (CFDSRC) bit field in the Main Clock Control C
(CLKCTRL.MCLKCTRLC) register has the value 0x0
and the main clock
is monitored, writing a ‘1
’ to the Clock Failure Detection Test
(CDFTST) bit in MCLKCTRLC will trigger a fault that will change the main clock to
the start-up clock source.