Keil: SWDIO no target connected

[Francesco Sfragara]

Posted on February 19, 2018 at 14:48

I'm using a stm32f407vg board. Suddenly I can't download my code to flash memory anymore. I'm using the keil toolchain. I tried stm32 st-link utility, but it can't connect to target either. I tried the option 'connect under reset', but it didn't work. I tried to unistall and install again the st link drivers and utility, but it didn't work. 

Can somebody please help me? Thanks.

[Tesla DeLorean]

Posted on February 19, 2018 at 15:32

Try pulling BOOT0 high, reset, and program/erase via ST-LINK Utilities

[Andrew Neil]

Posted on February 19, 2018 at 15:56

Cross-post: 

http://www.keil.com/forum/63376

 

[ACarb]

I've solved the issue following these steps:

-Install STM32 ST-LINK Utility;

-Open it, click on ST-LINK -> Firmware update;

-Plug your board, then click on Device Connect. If the board is recognised proceed with the firmware update (click yes), otherwise check if the drivers are correctly installed;

-Click on Target -> Settings. Under "Mode" select "Connect under reset". Leave all the other settings as default;

-Go on Target -> Connect. You are now connected to the board (see the registers);

-Finally click on the red Rubber figure (Full Chip Erase).

Now you should be able to download your code into the flash using Keil.

[RKlaj]

Hi, thank you for sharing the solution! I had the same issue and it worked for me too.

[ersinkecis]

hi, thank you for all.

but this solution is not working for me. :(

sometimes connecting. sometimes does not connect.

Is there anyone have an idea?

STLinkUSBDriver.dll v5.1.2.0

ST-LINK Firmware v2.J34.S7

[Tesla DeLorean]

Does your device go into a low power mode? Interfere with clocks, or pins related to SWD interface? NRST connected?

Try "Connect Under Reset"

[ersinkecis]

like you said, because I use a low-powered power supply. thank you so much.