Why ST-Link programmer on NUCLEO-XXXXRX works while NUCLEO-XXXXRX-P does not?

[abaldur]

Hi

For some time I have been using the ST-Link programmer from a NUCLEO-L452RE board for programming a custom STM32 board (external MCU). It has been working very well.

Recently, I have acquired a NUCLEO-L452RE-P, which has a bit different ST-Link programmer. For instance, it uses a micro USB connector as opposed to a mini connector. Also, it has an extra jumper. But aside from that, they look pretty much the same.

The thing is, I cannot get the NUCLEO-L452RE-P programmer to work on the same custom STM32 board. I have connected it the same way as I do for the NUCLEO-L452RE using the same SWD cable. Both ST-Link programmers have the same (latest) firmware V2J33M25.

I use Atollic TrueSTUDIO which reports the following error:

Error in initializing ST-Link device.

Reason: (4) No device found on target.

Can anyone explain why they are not compatible?

Thanks

/ abaldur

[Uwe Bonnes]

I see CN2 jumpered on both boards. To program an external device, you need to remove them. Pehaps you did that, but you did not mention, so just in case.

[AvaTar]

The new part number and the different appearance suggests the manual was updated as well. Did you check ?

I wouldn't bet on it, though ...

[abaldur]

Hi AvaTar. I have looked in the user manuals for both boards (UM1724 and UM2206). I have not been able to find anything that could explain it.

[AvaTar]

I have neither of your L452 Nucleos - already too much of those boards, and too little time.

Have you reviewed the schematic (of the new board), especially the SWD connection, and cross-checked the board/PCB with the schematics ?

ST's documentation department seems to have a little backlog recently.

[abaldur]

Hi Uwe. Thx for the quick reply. The CN2 jumpers have been removed. On both ST-Link programmers, I have removed ALL jumpers. Only the SWD connector and the UART connector is used. That is CN3 (SWD) and CN4 (UART) on NUCLEO-L452RE-P and CN4 (SWD) and CN3 (UART) for NUCLEO-L452RE.

[Mike_ST]

• CN2 should be unpopulated.
• If the MB1319B is in original condition, make sure JP6/IDD is connected to bring VDD_MCU to the level shifter U6.
• If you separated the ST-LINK from the target board. You won't have VDD MCU, and the level shifter U6 will not be powered, you have to power it with 3.3V or populate R23 with 100 Ohms.

[abaldur]

Hi @Mike_ST​ 

The ST-Link is separated from the target board.

I have connected my external MCU to the following pins on the SWD connector (CN3):

• CN3.Pin2 (T_JTCK) -> SWCLK
• CN3.Pin3 (GND) -> GND
• CN3.Pin4 (T_JTMS) -> SWDIO

The rest is left unconnected, and the target MCU is powered separately from a 5V USB supply.

I have tried populating the R23 resistor (which was mounted from factory on the NUCLEO-XXXXRX variant). The result is the same:

Error in initializing ST-Link device.

Reason: (4) No device found on target.

/ abaldur

[Mike_ST]

You absolutely need to connect pin 1 on CN3 connector. If I'm correct, it is an input that sense the target MCU voltage 1.8 or 3.3V. So please connect to 3.3V

[Mike_ST]

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