I'm using a stm32f407vg board. Suddenly I can't download my code
to flash memory. It gives me this error " Debugger - Cortex-M error:
no target connected". In options for target > Debug > Settings
in SW Device tab I see " SWDIO: Error No target connected".
How can I solve this?
Start by testing basic connectivity & comms with ST's ST-Link
* If that doesn't work, then you have a fundamental issue -
nothing to do with Keil;
* If that does work, then the issue is somewhere in your Keil
I assume you are connecting using the on board debugger. If so,
here are some ideas for troubleshooting a ST-Link.
I) Test with a pack example
If the top right of the dialog says "No ST-Link detected", or on
the top left, next to "Unit" the pull down box is empty: - Make sure
there are no Windows USB drivers or board debugger firmware issues.
If not - Swap out USB cables - Don't connect the ST-Link to your
computer via USB hub
If the box on the top left says - "Unknown target connected" - On
the middle-left of the screen, in the 'Target Com" box, switch the
Port from "JTAG" to "SW" - ST-LINK requires a Serial Wire interface,
If that works, close the dialogues. Still using the sample pack
example, Select Debug-> Start/ Stop debug session. If you get a
pop up box, that says
I had this same issue with my STM32F446RE Nucleo board. This is
what I had to do to get my onboard ST-Link to talk to uVision
-Download the STM32 ST-LINK Utility tool and try to connect to the
STM32 ST-LINK Utility:
-If the Utility tool fails to connect with the board try tying
your boot0 pin high, resetting the board, and reconnecting. On my
board this meant using one of the extra jumpers from CN11/12 and
connecting pins 7 (boot0) and 5 (VDD) together. Your board's User
Manual will tell you where the boot0 pin is and might also tell you
how to tie it high. If this doesn't work then the rest of my
instructions may not work for you.
-Once connected to the board, in Utility go to menu option ST-Link
-> Firmware update. A new window will appear, select "device
connect". The window will determine if your ST-Link firmware is out
dated and give you the option to update it, select
-Return to uVision and try flashing to your device again without
boot0 tied high.
-If still failing, tie boot0 high again and retry flashing the
device in uVision. If this works, then retry flashing with boot0 tied
This worked for me, hope it helps.
This worked, thanks!
Maybe some of the circuits on the board are powerless