Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Silicon Labs/Series1/EFM32GG11B/EFM32GG11B840F1024GM64/I2C1/RXDATAP#0x0
Receive Buffer Data Peek Register
RX Data Peek
https://github.com/cmsis-svd/cmsis-svd-data