Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/STMicroelectronics/STM32U599/OTG_HS/DOEPTSIZ0#0x0
The application must modify this register before enabling endpoint 0.
XFRSIZ
PKTCNT
STUPCNT
https://github.com/cmsis-svd/cmsis-svd-data