Size of Option bytes on STM32H743

[deckhard]

The size of system memory on STM32H743 is 2 sectors of 128KB each.

What is the size of the option bytes block?

[TDK]

Option bytes are not directly accessible. So in one sense they don't have a size as they don't exist anywhere in the memory map.

You can only modify them indirectly through the register interface shown in the FLASH section of the RM, which gives you access to portions of 8x 32-bit words.

[deckhard]

Thanks.

Is it possible to write into System memory region from user flash regions in RDP level 0 ?

[TDK]

System memory is read only.

[deckhard]

Is possible while running form Flash in RDP level 0 to:

1. write code into SRAM
2. Change the BOOT_ADDR to SRAM
3. Reset the MCU via AIRCR register i.e NVIC_SystemReset()
4. Boot into SRAM code

Is it possible?

I know that if RDP level 2 is applied you can only boot into user flash or into System Memory.