ST-LINK/V2 Failed to detect STM32F446RC on custom board with pin headers shown in images.

[DCont.1]

Hi!

I am currently trying to connect the ST-LINK/V2 to my custom board which is using a STM32F446RC. I am able to detect the ST-LINK using both the STM32CubeIDE or the STM32 ST-LINK utility, however this is only displaying the serial number. but it is failing to detect the target (MCU).

I have added a picture of the header on the custom board and the header am using for guidance.

Am not sure whether to use the JTAG connections or the SWD connection guidelines.

[Tesla DeLorean]

Seems like your pin numbering is completely rotated vs ARM 10-pin

Just use the SWD connections, the ST-LINK expects 3.3V on Pin 1 or 2 of their header

GND, VCC, SWDIO/TMS, SWCLK/TCLK minimum

NRST allows for connect under reset

SWO/TDO allows for debug channel

Check orientation of your STM32

Make sure VDDA is powered

Check voltage/caps of VCAP pins, should see 1.25 V or about

Check level on NRST, should be high

[DCont.1]

@Community member​ Thank you for replying. So I tried connecting it using the SWD connections. I have attached a picture of the table I used for connection. the SWO pin would be PB3 on the custom board header. Everything else maps the same. I still receive a fail connection.

[DCont.1]

Using the STM32CubeIDE I change the debugger configuration to openOCD just for the sake of getting some output, the error I receive on the console is the following:

Error: target voltage may be too low for reliable debugging

Error: init mode failed (unable to connect to the target)

Using GDB server I get:

Error in initializing ST-LINK device.

Reason: No device found on target.

The BOOT0 and BOOT1 are both hard-wired to GND on the custom board

[DCont.1]

The reading on the VCAP is about 4.2 mV

[DCont.1]

Additionally, if I disconnect the ST-LINK/V2 from the computer but leave it connected to the custom board, the ST-LINK/V2 led stays on. Am not sure if this is a positive indication.

[DCont.1]

Apologies, the VCAP pin has a voltage of 1.14 V and NRST is high.

I however wired the BOOT0 and BOOT1 to ground, which means is booting from the user flash memory. Could this be the issue?

[TDK]

Recheck connections. If it's not detecting the target voltage is 3.3V, something is off. BOOTx connection doesn't matter for debugging, unless your program reassigns SWD pins.

Try STM32CubeProgrammer.

[Tesla DeLorean]

No shouldn't matter. It does however foreclose on the ability to get a signs-of-life response from the System Loader via a USART

The inability to connect typically falls into two categories, the wrong pins, or device non-functional.

The ST-LINK via Utilities or STM32 Cube Programmer, should be able to report the VCC / VTarget voltage

NRST High suggests the analogue side is powered.

Close to 1.2V on the VCAPs suggests orientation is correct.

[DCont.1]

Thank you @Community member​ and @TDK​ I will go ahead and probe the SWD and SWCLK. I will post schematics along with the results from the probing.