Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32f7/STM32F767/TIM1/AF2#0x0
alternate function option register 2
BRK2 BKIN input enable
BRK2 DFSDM_BREAK enable
BRK2 BKIN2 input polarity
https://github.com/modm-io/cmsis-svd-stm32