Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Silicon Labs/Series1/EFM32GG11B/EFM32GG11B820F2048IQ100/ETH/SPECADDR1TOP#0x0
Specific Address 1 Top
Specific address 1 MSB
MAC SA or DA selection
https://github.com/cmsis-svd/cmsis-svd-data