Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Silicon Labs/Series1/EFR32MG12P/EFR32MG12P433F1024GM48/GPCRC/CTRL#0x0
Control Register
CRC Functionality Enable
Polynomial Select
Byte Mode Enable
Byte-level Bit Reverse Enable
Byte Reverse Mode
Auto Init Enable
https://github.com/cmsis-svd/cmsis-svd-data