Nucleo H723ZG, DEV_TARGET_HELD_UNDER_RESET

[Lysandros]

Hello community,

has anyone encountered  DEV_TARGET_HELD_UNDER_RESET issues with a Nucleo Board (ST-Link V3) ?

I have multiple Nucleo H723ZG and for some reason I can't connect to any of them since a few days.

I have tried:

• swapping USB cables and adapters
• using a docking station or the notebook ports themselves
• external power supply vs. power supply over USB
• applying the board reset jumper and the ST-Link reset jumper
• trying to first power-up, then connect to computer
• the ST-Link Upgrade tool
• different IDE like VScode, STM32CubeIDE
• serial COM tools like Minicom
• turning off the computer and starting again

With all the combination I can max. achieve to see the board in the COM port (e.g. as /dev/tty.usbmodem21103), nothing more. Some boards draw 0.35A from remote which I find high, others only 0.1A. Others draw 500mA from the USB; which I find very high. It appears as if this is an issue with my computer...

        STLINK-V3:

          Product ID: 0x374e

          Vendor ID: 0x0483  (STMicroelectronics)

          Version: 1.00

          Serial Number: 0018001C3156501520323443

          Speed: Up to 480 Mb/s

          Manufacturer: STMicroelectronics

          Location ID: 0x01100000 / 1

          Current Available (mA): 500

          Current Required (mA): 500

          Extra Operating Current (mA): 0

Any ideas?

Many thanks

[Tesla DeLorean]

Same software on all of them, breaking the same way?

If you add a jumper between BT0 (BOOT0) and VDD pins, is the core accessible after a board level power cycle?

[AScha.3 · Accepted solution]

Hi,

 use CubeProgrammer, show , whats its telling about your st-link V3 ;

--if problem , set :

then connect , under reset, and show, whats its telling .

...here from a H743 -> V3mods

[Lysandros]

Thanks for both hints.

With one of the boards, I even managed to connect tin the CubeProgrammer.

And the board appears in the Terminal as /dev/tty.usbmodem213203

I have the impression, that other software (e.g. VScode) can't connect to the board if I don't close the STM32CubeProgrammer first, could this be? I managed to flash software, but only after first disconnecting from both Minicom and STM32CubeProgrammer...

[AScha.3]

So you can connect now - good.

+

>can't connect to the board if I don't close the STM32CubeProgrammer first, could this be?

Maybe, as long as a device is "used"/connected by any program, others have no access.

But (on Win or my Linux system here) CubeProgrammer only occupies the port on "connect(ed)" .

Others, like terminal programs, most time take the used port and then occupy the port permanently .