Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/STMicroelectronics/STM32F7x8/OTG_FS_HOST/OTG_FS_HFNUM#0x0
OTG_FS host frame number/frame time remaining register (OTG_FS_HFNUM)
Frame number
Frame time remaining
https://github.com/cmsis-svd/cmsis-svd-data