Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Silicon Labs/Series1/EFM32GG12B/EFM32GG12B410F1024GQ100/LEUART0/TXDATA#0x0
Transmit Buffer Data Register
TX Data
https://github.com/cmsis-svd/cmsis-svd-data