Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Keil/AT32A403Axx_v2/I2C1/CTRL2#0x0
Control register 2
Input clock frequency
Error interrupt enable
Event interrupt enable
Data transmission interrupt enable
DMA transfer enable
DMA transfer end indication
https://github.com/cmsis-svd/cmsis-svd-data