Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Silicon Labs/Series1/EFM32PG1B/EFM32PG1B100F128IM32/CMU/HFCLKSTATUS#0x0
HFCLK Status Register
HFCLK Selected
1 (HFRCO): HFRCO is selected as HFCLK clock source
2 (HFXO): HFXO is selected as HFCLK clock source
3 (LFRCO): LFRCO is selected as HFCLK clock source
4 (LFXO): LFXO is selected as HFCLK clock source
https://github.com/cmsis-svd/cmsis-svd-data