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How to resolve a problem with ST-Link/2 not connecting to target

Duggan.Robert
Associate II

I have been working with the trial version of the IAR IDE and with the STM32 processor family.

I have been using the ST-Link/2 device to connect to my target for debugging with no problems.

I began having a problem when starting debug, I am getting a message for the driver:

Fatal error: ST-Link, No MCU device found / Session Aborted!

I've tried updating the ST-Link firmware and reinstalling the driver but no luck.

I've also installed the ST-Link Utility and this does not connect either. I find the same problem with several ST-Link devices and all target boards. 

However, a Nucleo board does function properly.

Does anyone have any suggestions?

1 ACCEPTED SOLUTION

Accepted Solutions
Duggan.Robert
Associate II

Thank you Gentleman. The problem was, indeed, with the power supply!

View solution in original post

6 REPLIES 6
Uwe Bonnes
Principal II

Did you try connect under reset? Try also other combinations of debugger/target if you have access to more devices.

Duggan.Robert
Associate II

Thank you Uwe. I have tried three different types of target board (all operated with ST-Link/V2 dongle previously.)

The ST-Link Utility will communicate with the dongle, but not with any target connected.

Check that the ST-LINK can see and report the Target Voltage, pin 1/2 need to see power.

Strap BOOT0 high to observe if the part is responsive when executing ROM code.

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Strapping boot network is useful if the user code is in stop mode. A simple workaround to reduce this pb is in the user code to delay going to power mode after reset so you have a time window to connect...

Duggan.Robert
Associate II

Thank you Gentleman. The problem was, indeed, with the power supply!

Well that, but also stuff like configuring the pins very tight in the ResetHandler. It is a diagnostic method to rule out user code, and a lack of NRST pin connectivity.

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