DEV_TARGET_HELD_UNDER_RESET error from ST-LINK

[G0MGX]

I'm a complete newbe at directly programming STM and am learning using a Nucleo-l476RG board. When I try and run my code from STMCubeIDE I get errors failed to execute MI command and then "the system tried to join a drive to a directory on a joined drive".

I tried connecting directly from STM32Cube programmer and I get DEV_TARGET_HELD_UNDER_RESET.

Yesterday the board was working and I was prompted to update the ST-Link firmware.

I'm lost and would be grateful for any pointers.

Mark

G0MGX

[Uwe Bonnes]

Check that nothing pulls doen the reset line

[HSaee.1]

I have the same problem, try hold reset button and connect with stlink utility software maybe in your case it work.

But for me was not the answer.

for me it is a same scenario my mcu programed and worked well and very perfect I even programed it for 4 or 5 times but after that I get

DEV_HELD_UNDER_RES error and it look like it is halt in the first line and not working.

Please someone help US!

SOS ... SOS ... SOS ... SOS ...

[Tesla DeLorean]

Not clear if this is code related, but if you put broken code on the device one approach is top strap BOOT0 High so it goes into the loader instead. ​

[JRF.1]

Have you solved the problem? I'm having the issue here :\

[HSaee.1]

if you configured the debug interface in cubemx and now your board does not connect read entire comment but if not choose the under reset mode and hold reset button and click on connect just wait a moment and release button and you will connect to mcu erase it and program it with a program which configure the debug interface you will find a lot in google .

I have same issue, and I asked it in this forum. interesting thing is stm shows short circuit after this happen.

I design and solder my boards and first I though there should be a design problem but it was not after that I get suspicious to soldering ( temperature and even solder paste and so on) but that was not problem.

and other interesting thing is if you leave board alone for while ( about a day or hour) it will be okay it is like that some capacitor get empty and problem get solve something inside the mcu ( I do no t know maybe rom loose his memory I really do not know)

[Alexmouse]

I've just had my 401RE-Nucleo do this whilst debugging an external target. I've isolated the local STM32F401 processor reset, and the reset is still held low, so the STM32F103 ST-Link processor must be at fault? A reset pin failure? They are cheap enough, but there was no good reason for it to fail.

[Alexmouse]

Curiously, having isolated the reset line between ST-Link & local target processor, I can still program & debug the local target processor. I can't use it as an external debugger, because of the broken reset link on the ST-Link.

[KyleH]

Not sure if this can solve your issue, just for your reference, I had the same issue recently, but when I measure the voltage of the capacitor(C18 in my case) of nRST pin, it shows 1.6v, but after the measurement, the connection works, I guess it's because when I measure it, the capacitor get released and cleared, please see if this works for you.

[RMerc.2]

Hi! 
I tried to follow the method provided in other forums (which is holding reset for 1-2 seconds after pressing connect in the GUI) but I had no luck! 

So attempted to change settings and voila! it worked. check out the image below: 

(Just in case)

Setting

Port: SWD

Freq: 4000

Mode: Hot plug

..

Reset Mode: Hardware Reset

...

Hope this helps!