Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32f4/STM32F427/I2C3/CR2#0x0
Control register 2
Peripheral clock frequency
Error interrupt enable
Event interrupt enable
Buffer interrupt enable
DMA requests enable
DMA last transfer
https://github.com/modm-io/cmsis-svd-stm32