Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Silicon Labs/Series1/EFR32ZG13P/EFR32ZG13P531F512GM32/USART1/RXDATAX#0x0
RX Buffer Data Extended Register
RX Data
Data Parity Error
Data Framing Error
https://github.com/cmsis-svd/cmsis-svd-data