Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Silicon Labs/SiM3_NRND/SIM3L166_C/PLL_0/CALCONFIG#0x0
RANGE=RANGE0
Calibration Configuration
DCO Dither Setting.
DCO Calibration Value.
DCO Range.
0 (RANGE0): DCO operates from 23 to 37 MHz.
1 (RANGE1): DCO operates from 33 to 50 MHz.
2 (RANGE2): DCO operates from 45 to 50 MHz.
https://github.com/cmsis-svd/cmsis-svd-data