2023-12-10 12:10 AM
Hello,
I have 3 of these (chinese origin) boards, 2 are failing communication, 1 is ok.
In essence my STLINK-V3SET fails to connect to the board but the led's on the brand new board are blinking. Therefore the MCU processor is running. I measured the 3.3V power supply pins on my STLINK and they are not powering the board (board is powered externally), so a 3.3 conflict does not seem to be the origin of the broken board, my question: are there any other steps that can be taken to repair the JLINK interface or at least find the origin of the problem?
2023-12-13 04:08 AM
Hello,
we don't know this board, do you have the schematic ?
You're talking about JLINK and ST-LINK. Which one are you using ?
Maybe the board that is not working already has a firmware inside that when executing prevents to use the debug pins.
Solution would be to connect under reset or connect via bootloader with boot0 set to 1 and perform a mass erase.
2023-12-15 12:07 PM - edited 2023-12-15 12:07 PM
Hello,
Schematic drawing see attachement.
As I see jlink with both SWD and JTAG capabilities via ST-LINK V3.
Both work correctly on twin board that is OK.
Tried the following:
Where pin 3 and 2 are connected on pin 8.
So I suppose all is ok.
What I do see is that the 3.3V on the bogus board is there but the ac voltage on the Y1 is much lower compared to the OK board. (140 mV ok & 14 mV nok). However one of the LED's on the board is blinking so the processor is running. I also replaced Y1 with a brand new one. However I do not believe Y1 is necessary for an operational board.
So thank you for the reply but no result yet.
2023-12-15 02:53 PM
Looks more like a Generic ARM 20-pin JTAG, not "J-LINK" specifically, although the Silk-Screen suggests that what they referred to it as
You could select "SWD" as the connection method, it uses a sub-set of the full JTAG pins.
ST Tools may reject connectivity if the parts is a counterfeit or clone device. Board and processor need to be properly powered for the SWD/JTAG interface to be viable.
2023-12-16 02:52 AM - edited 2023-12-16 03:32 AM
Thank you for the info.
I have 3 boards, identical design (except for the color of the headers :).
The first board, the older one, SWD and JTAG operating fully no connection problems whatsoever.
The 2 recent boards, SWD, JTAG, even connect under reset with Boot 0 = 1, no connection.
Therefore, sorry to say and respect for what you do for the people on the forum, but your post did not hit the target this time.
2023-12-25 12:05 PM
I connected my scope to the board and this gave me the following image: (SWD connection, red is clock)
Do you have any idea what kind of protocol I need to select or any other insights that could lead to the solution i.e. my ST-LINK programmer finding the target board?
Is there a way to find out if the MCU is counterfeit? The imprint seems genuine.