Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Silicon Labs/SiM3_NRND/SIM3C167_B/RTC_0/LFOCONTROL#0x0
LFOSCEN=DISABLED
LFOSC Control
Low Frequency Oscillator Enable.
0 (DISABLED): Disable the Low Frequency Oscillator (LFOSCn).
1 (ENABLED): Enable the Low Frequency Oscillator (LFOSCn).
https://github.com/cmsis-svd/cmsis-svd-data