Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32n6/STM32N645/OTG1/OTG_HFNUM#0x0
OTG host frame number/frame time remaining register
Frame number
Frame time remaining
https://github.com/modm-io/cmsis-svd-stm32