Hello,
The FLL factor 2197 can be selected in the FBE and FEE MCG modes only (FLL must use a 32768 Hz external clock source). When an internal oscillator is used it is not possible to set the DMX32 bit. There is a risk to damage device. See the reference manual instructions:
In FBI and FEI modes, setting C4[DMX32] bit is not recommended. If the internal
reference is trimmed to a frequency above 32.768 kHz, the greater FLL multiplication
factor could potentially push the microcontroller system clock out of specification and
damage the part.
Best Regards,
Marek Neuzil