Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Silicon Labs/Series1/EFM32GG11B/EFM32GG11B820F2048IM64/USB/HFNUM#0x0
Host Frame Number/Frame Time Remaining Register
Frame Number
Frame Time Remaining
https://github.com/cmsis-svd/cmsis-svd-data