Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/STMicroelectronics/STM32F7x8/FMC/SDCMR#0x0
SDRAM Command Mode register
Command mode
Command target bank 2
Command target bank 1
Number of Auto-refresh
Mode Register definition
https://github.com/cmsis-svd/cmsis-svd-data