Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Silicon Labs/Series1/EFM32GG11B/EFM32GG11B420F2048IL120/USB/DIEP1_TSIZ#0x0
Device IN Endpoint x+1 Transfer Size Register
Transfer Size
Packet Count
Multi Count
https://github.com/cmsis-svd/cmsis-svd-data