ST-LINK V2 Can not connect to target! Help Me!!

[sim20]

Posted on August 22, 2016 at 14:52

Hi All,

Connect the pins were as follows: SWD ST-LINK V2 and between MCU.1:VDD - VDD3:GND - GND7:SWDIO - PA13_SWDIO 9:SWCLK - PA14_SWCLKPDR_ON: 10k pull-upBOOT0: 10k pull-downBYPASS_REG: 10k pull-downVCAP: 2.2uF GNDVDD:1.8VVDDUSB:1.8VVBAT:1.8VVDDA:1.8VThe test MCU is in STM32F746NGH6.VDD is 3.3V when the connection was good, do not connect change with VDD 1.8V, as shown below.On the MCU specifications are listed as available from 1.7V to 3.6V.Can not connect to target!Please select ''Connect Under Reset'' mode from Target->Settings menu and try again.If you're trying to connect to a low frequency application , please select a lower SWD Frequency mode from Target->Settings menu.What's the problem?

Thank you.

Best regards,

gyosun.

[Walid FTITI_O]

Posted on August 22, 2016 at 15:22

Hi gyosun,

Upgrade the ST-Link firmware to V2-1 version through this

http://www.st.com/content/st_com/en/products/embedded-software/development-tool-software/stsw-link009.html

and try again. -Hannibal-

[Tesla DeLorean]

Posted on August 22, 2016 at 16:38

VDDUSB isn't going to be viable at 1.8V

I seem to have to constantly repeat the same advice. Review the voltage on the VCAP and NRST pins. Connect NRST on the debugger header. Consider if the ST-LINK is supporting 1.8V through it's buffers. Not really going to dig into the PDR/BYPASS Consider if you can connect to the USART in the System Loader (BOOT0=1) to see if you can show signs of life for the STM32 chip that way.

[ierturk]

I have same problem with battery powered custom board with STM32L431. The MCU connects successfully when VDD is under 3.3V but not above 3.3 - 3.6V. The configuration as follow

VDD is about 3.6V

GND

NRST

SWDIO -> PA13

SWDCLK -> PA14

SWO -> PB3

Any suggestion? Thanks in advance.

ierturk

[Tesla DeLorean]

And this is using an official ST-LINK/V2 or some bootleg?

[ierturk]

Yes it is official ST-LINK/V2.

[ierturk]

Yes it is official ST-LINK/V2.