Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32n6/STM32N645/FMC1/FMC_BCHDSR0#0x0
FMC BCH decoder status register 0
Decoder uncorrectable error
Decoder error found
Decoder error number
https://github.com/modm-io/cmsis-svd-stm32