ST-Link/v2 can't connect to MCU

[Fabrizio32]

Hi,

I’m using a NUCLEO-C031C6 64 board.

I successfully setup the tool chain and ran several test from STM32CubeMX templates, directly compile and programming through STM32CubeIDE.

Until this morning, everything was working fine.

But I have lost the connection to the MCU later on.

 

From STM32CudeIDE:

Target unknown error 19

Error in initializing ST-LINK device.

Reason: Unknown. Please check power and cabling to target.

 

Using of STM32CubeProgrammer:

• Recognized as mass storage
• On board ST-LINK/V2 is recognized, updated to version V2J47M34 successfully
• Full chip erase and board recognition works fine on the NUCLEO-G031K8 board

But I have repetitively following messages while I try to connect ():

 

I have tried unsuccessfully:

• under reset mode 
• external SWD ST-LINK

 

 

How can I debug futher?

Did I miss something?

Thanks!

 

 

 

[Andrew Neil]

Is your software using low-power modes, and/or reconfiguring the SWD pins ?

Have you enabled any security/protection ?

 

Try connecting from CubeProgrammer.

 

 

[Fabrizio32]

 

The program is a basic CubeMX configuration template. I have no low-power mode or security settings.

I played with clock configuration and somehow disabled the “serial wire” debug in one of my tests. Beyond this point, I couldn’t recover the connection with the MCU 

[Andrew Neil]

Connecting under hardware reset should get you out of that.

Or use the System bootloader.

[db16122]

Until this morning, everything was working fine.

But I have lost the connection to the MCU later on.

 

between this period of time, is there any change on the board or your laptop? looks wired...

[Fabrizio32]

Thanks all for your suggestion.

 

I tried several reset configuration, both on the board and with CubeProgrammer options.

Everything was normal on the scope from ST-Link side (SWD signal, NRST).

I finally get back access to the STM32 using the option “power down”:

 

 

I erased completely the MCU and I can now program it again with CubeProgrammer or directly after compilation with CubeIDE.

 

Thanks!

[db16122]

well done and congratulations~~