Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Silicon Labs/Series1/EFM32GG11B/EFM32GG11B420F2048GQ64/USART3/ROUTELOC1#0x0
CTSLOC=LOC0, RTSLOC=LOC0
I/O Routing Location Register
I/O Location
0 (LOC0): Location 0
1 (LOC1): Location 1
2 (LOC2): Location 2
3 (LOC3): Location 3
4 (LOC4): Location 4
5 (LOC5): Location 5
6 (LOC6): Location 6
https://github.com/cmsis-svd/cmsis-svd-data