I would like some advice on suitable SDRAM, EEPROM,Flash memory , Flexible memory controller (FMC)etc. and other memory sticks. For storing data from rotary encoder as such as counter when clock wise or counter clockwise i use stm32h750vbt6

[non]

I want to know the proper way.

[S.Ma]

If the rotary encoder is processed by the MCU and update a global variable (like the volume level of a car radio), and you want to keep the position value when restarting the code (power up or reset and rerun the app in debug mode), the easiest would be to store the value in an EEPROM such as M24128. Writing will take 5 msec max for a multi-write byte update using I2C bus (even just using GPIO using I2C Bitbang)

An example for STM32C0 can be found here.

Then, once optimisation (cost) becomes important, you might try to use embedded MCU flash sectors to emulate to some point the external EEPROM. One step at a time.