After I write to flash memory I cannot do it again upon reflashing entire program onto chip, how to avoid this?

[WBäck.1]

I have an STM32F407 board and have worked out how to flash a certain flash-sector as well as erasing it.

My problem is that whenever I have written to flash, and I reboot my board, I cannot flash again until I reflash the entire programme from STM32CubeIDE. As far as I've understood it is that whenever flash is accessed it will lock it afterwards to avoid unauthorized access. But I want to be able to do it indefinitely without having to reflash the code. How do I do this?

My code is at the moment:

FLASH_Unlock();
FLASH_OB_Unlock();
 
FLASH_EraseSector(FLASH_Sector, VoltageRange);
flashFunction(param);
 
FLASH_Lock();
FLASH_OB_Lock();

Any suggestions what to do to be able to write to flash how much I want without reflashing?

[Piranha]

Read the reference manual and debug the code. Look at FLASH status register, especially the error bits.

[FBL]

Hello @William Bäckström​,

As mentioned in the reference manual, the main Flash memory block is divided into 4 sectors of 16 Kbytes, 1 sector of 64 Kbytes, and 7 sectors of 128 Kbytes. You can program/erase the sectors word by word using HAL_FLASH_Program(); HAL_FLASHEx_Erase();

Maybe, jumping and executing your code from RAM could be a better choice.

[Piranha]

The person cannot implement a simple thing, but you are suggesting a more complex and rarely necessary one. Great advice!

[FBL]

Thank you for your feedback @Piranha​. Although, that's an interesting opinion, but I prefer to help anyways. We are here to help each other!