18.6.4 Digital Frequency Locked Loop (DFLL48M) Operation
The DFLL48M can operate in both open-loop
mode and closed-loop mode. In closed-loop mode, a low-frequency clock with high accuracy
should be used as the DFLL48M reference clock to get high accuracy on the output clock
(CLK_DFLL48M).
Important: The
DFLL48M can only be used with LDO regulator.
The DFLL48M’s output can be used as a source for the generic clock generators (GCLK.GENCTRLn.SRC = DFLL).