ST Bootloader behavior when flash is not programmed

[kf_SEA]

Hi everyone!

I found the following diagramm in AN2606 and my understanding was, that the bootloader will be executed when there is no valid content in flash memory.

I know that boot pins or a jump from user code can be used to enter the ST bootloader, but it would be interesting for me if it will be executed for new chips which were not programmed before, too. In this case they could be flashed without SWD/ST-Link (boot pins are not an option here).

I tried to erase the complete flash to simulate a new chip, but it did not become active as DFU device in ST bootloader.

It seems to be a misunderstanding on my side. Can you give me further information how to interpret?

Thanks and regards

KF

 

[AScha.3]

Hi,

>the bootloader will be executed when there is no valid content in flash memory.

Right, but there are some details, see AN2606 , table 2 :

setting of option bytes and -maybe- bootloader version .

+ 

 

+ Did you power cycle it after full erase ? (and look, whats you option byte setting)

+ Did you try with a 100% new chip?