Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32f4/STM32F446/FMPI2C/TIMEOUTR#0x0
Timeout register
Bus Timeout A
Idle clock timeout detection
Clock timeout enable
Bus timeout B
Extended clock timeout enable
https://github.com/modm-io/cmsis-svd-stm32