I create a PCB with stm32F411 and i obtain: "Can not connect to target" with st-LINK Utility

[bvale.2]

Hello,

For a project, I created a PCB with an STM32F411 using a 10pin JTAG port for SWD programming.I tried to connect my card using the ST LINK V2 box and the ST Link utility software but I get the following error:

The st link works because I can program another card using a stm32F042. I tried all the connection parameters and to play with the BOOT0 pin status but nothing works.

Can anyone help me to program my card?

[bvale.2]

>> The other secondary method is to probe one of the System Loader's UARTs responds to the 0x7F data pattern at 9600 8E1, in the BOOT0=HIGH cases.

Focus on causal reasons why chip is dead in the water...

Sorry, I don't understand how to do it?

>> Does the ST-LINK see a voltage? VTarget

Cube Programmer said Vtarget = 3.2V

 

>> Can you take a picture of the IC on the PCB? Points for clear, sharp and in focus.

Here is a part of my wiring diagram, the stm32 CubeIDE configuration and a picture of the board. Pin 1 is on the bottom right. BOOT0 is given to a 10k Ohm resistor for which I can choose to ground or 3.3V

 

[TDK]

You've grounded VCAP. That will cause the chip to not function. This pin outputs ~1.2V and needs to be bypassed to GND with a ~2.2uF cap.

 

Review the reference layout documentation.

https://www.st.com/resource/en/application_note/dm00115714-getting-started-with-stm32f4xxxx-mcu-hardware-development-stmicroelectronics.pdf

Tesla asked you about this in the very first post.

> Check voltage seen on VCAP pins, and placed caps.

Edit: Not only that, but you replied and said that you've checked it.

> I have already checked all this

[bvale.2]

Sorry I didn't see this feature in the documentation. I unsoldered this pin and soldered a 2.2uF capacitor as indicated. Now the card consumes much less and the value seems to me more coherent (10mA instead of 150mA).

I still can't connect to the board but I will read the documentation more carefully before coming back to you.

Thanks for your help

[TDK]

After looking at your picture again, the only thing you have populated is the STM32 and F1 and some cables. Might need some decoupling caps on there before it acts correctly. I guess there may be components on the other side.

[bvale.2]

Yes, I will order a new card changing the Vcap pin and putting a 4.7uF capacitance (because only one Vcap if I understood) and putting all the decoupling capacitance requested for the power supply. Yes I have components on the other side, and the board is printed on 4 layers.

Normally if I read the documentation well I should not have other problems?

[Tesla DeLorean]

I'd image it would get hot with the internal regulator shorted to ground. The core logic runs at about 1.25V, but can be functional/viable below that.

>>Sorry, I don't understand how to do it?

AN2606 describes the boot loader, AN3155 the UART protocol.

By default there is no outward pin toggling, or clocks than one might see on classic MCU as an indicator that it's alive. For the STM32 you can send signals which the boot loader can respond too. Generally if neither the SWD/JTAG or the UART methods work the device is not running/powered. Synchronous logic needs POWER and CLOCKS, absent these things nothing happens.

[bvale.2]

Hello

I received my new PCB yesterday, after soldering it managed to make the board work.

I corrected the problem with the capacitance on Vcap and the decoupling capacitance on each power supply leg of the microcontroller

Thanks for all.