Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32f1/STM32F101/OTG_FS_DEVICE/DVBUSPULSE#0x0
OTG_FS device VBUS pulsing time register
Device VBUS pulsing time
https://github.com/modm-io/cmsis-svd-stm32