Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Silicon Labs/Series0/EZR32HG/EZR32HG320F32R67/USB/GRXFSIZ#0x0
Receive FIFO Size Register
RxFIFO Depth
https://github.com/cmsis-svd/cmsis-svd-data