Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32f4/STM32F412/OTG_FS_HOST/FS_HFNUM#0x0
OTG_FS host frame number/frame time remaining register (OTG_FS_HFNUM)
Frame number
Frame time remaining
https://github.com/modm-io/cmsis-svd-stm32