Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/STMicroelectronics/STM32W108/SC1_I2C/SC1_I2CSR#0x0
Serial controller I2C status register
NACK
BTF
BRF
CMDFIN
https://github.com/cmsis-svd/cmsis-svd-data