Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Silicon Labs/Series1/EFR32MG13P/EFR32MG13P733F512GM48/RTCC/RET2_REG#0x0
Retention Register
General Purpose Retention Register
https://github.com/cmsis-svd/cmsis-svd-data