SWD and GPIO

[Toraora]

Hi all,

I have an STM32L-Discovery which seems to have locked up. My best guess is that I configured certain GPIOs to output to an external LCD display, but these pins also happen to be connected to the SWD header. Would this cause problems (and why didn't the manual tell me to avoid this?).

Thanks,
toraora

 

[Harald Kapp]

I don't know the STM32, but I had a similar issue with an ATMEL processor. Turned out I had used the RESET input as port pin. This way in circuit programming was no longe rpossible.
In my case it helped to remove the CPU from the circuit and erase it completely using the high voltage programming mode. I don't know, perhaps the STM32 has such a capability, too?

And: the ATMEL manual contained the necessary information. It was my fault to overlook it. If that's an issue with the STM32, I'm sure the information is buried somwhere in the manual, too.

Harald