Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32f4/STM32F407/FSMC/SDRTR#0x0
SDRAM Refresh Timer register
Clear Refresh error flag
Refresh Timer Count
RES Interrupt Enable
https://github.com/modm-io/cmsis-svd-stm32