The STM32H743ZI MCU has 4 Kbytes of SRAM in Backup domain.
Is it possible to access this back up RAM?
I have found and tried this that works for the F429
But the RCC registers are a bit different on the H7
RCC->APB1ENR |= RCC_APB1ENR_PWREN;
is not found found in RCC_TypeDef.