connection fail via swd with jlink

RE: connection fail via swd with jlink

bini2007 — Thu, 13 Mar 2025 02:43:29 GMT

Thanks for your support.

I used another nRF52832 DK board as a debugger apart from nRF52833 DK and tested our target with j-link connection.

It works well.

In addition, maybe,

it might work well using nRF52833 DK as a debugger when I connect a female-to-female jumper wire, or a 2 pin header jumper to P22.

Thanks,
Jaehong Park

RE: connection fail via swd with jlink

Menon — Tue, 11 Mar 2025 12:41:24 GMT

Hello,

Have you made any soldering modifications or changes to the DK? (Please verify this.) It looks like the DK is not being detected.

You only need to follow the connections mentioned in this section.

Kind regards,
Abhijith

RE: connection fail via swd with jlink

bini2007 — Mon, 10 Mar 2025 01:35:44 GMT

Hi,

I have tested j-link connection between our target and DK board.

When DK board was connected with RTT Viewer on my PC, the noti message with "update on Jlink OB fw"showed on RTT Viewer.

And I update Jlink OB on my DK board and I tested again j-link via swd with my target.

Then the following errors happened. please advice me why this happened and jlink OB connection failed even with our target.

C:\Program Files\SEGGER\JLink_V794e>JLink.exe
SEGGER J-Link Commander V7.94e (Compiled Jan 15 2024 15:20:36)
DLL version V7.94e, compiled Jan 15 2024 15:18:46

Connecting to J-Link via USB...O.K.
Firmware: J-Link OB-SAM3U128-V2-NordicSemi compiled Oct  9 2024 11:00:56
Hardware version: V1.00
J-Link uptime (since boot): 0d 00h 02m 58s
S/N: 685079944
License(s): RDI, FlashBP, FlashDL, JFlash, GDB
USB speed mode: High speed (480 MBit/s)
VTref=3.300V


Type "connect" to establish a target connection, '?' for help
J-Link>connect
Please specify device / core. <Default>: NRF52833_XXAA
Type '?' for selection dialog
Device>
Please specify target interface:
  J) JTAG (Default)
  S) SWD
  T) cJTAG
TIF>S
Specify target interface speed [kHz]. <Default>: 4000 kHz
Speed>
Device "NRF52833_XXAA" selected.


Connecting to target via SWD
InitTarget() start
InitTarget() end - Took 108ms
Connect fallback: Reset via Reset pin & Connect.
InitTarget() start
InitTarget() end - Took 109ms
Cannot connect to target.
J-Link>

Please help me.

RE: connection fail via swd with jlink

bini2007 — Fri, 07 Mar 2025 16:01:22 GMT

Above link was "https://docs.nordicsemi.com/bundle/ug_nrf52832_dk/page/UG/dk/ext_programming_support_P20.html"

RE: connection fail via swd with jlink

bini2007 — Fri, 07 Mar 2025 15:59:31 GMT

Hi Menon,

Yes,

the issue occurs when you use an external j-link debugger, but there is no issue for programming when using the nRF52833 DK as the debugger.

However, there is still the issue for debugging for using RTT viewer even when using the nRF52833 DK as the debugger.

So,

I have looked more into the following link referring to nRF52832 DK. "docs.nordicsemi.com/.../ext_programming_support_P20.html"

Here, it says the more connection for reset pin ,apart from pins connection of swclk, swdio, vcc and gnd.

So,

can you tell me about the pin connections between our external target board and nRF52832 DK debugger.

Then the next time after solving it, I may have to solve issues between our board and j-link external debugger.

Thanks,

RE: connection fail via swd with jlink

Menon — Thu, 06 Mar 2025 13:30:50 GMT

Hello,

From your response, I understand that the issue occurs when you use an external debugger, but there is no issue when using the nRF52833 DK as the debugger. Please correct me if I’m wrong.

If that is the case, the problem is likely related to the connection between your J-Link debugger and your custom board. Could you please ensure that the power supply is stable while using the external debugger?

From the last shared logs, it appears that the target device is not being detected.

Kind Regards,

Abhijith

RE: connection fail via swd with jlink

bini2007 — Wed, 05 Mar 2025 06:31:44 GMT

Today, I use nrf52833 DK board as a debugger for our target device following this link.
The link is "">docs.nordicsemi.com/.../hw_debug_out.html" .

After test as above,

Our target is working good with debugger as DK board.

It is so good for us.

Then the connection problem with j-link device still happen as before.

Please advice us why to happen and how to solve.

RE: connection fail via swd with jlink

bini2007 — Wed, 05 Mar 2025 00:44:38 GMT

After seeing the link you suggested, I checked my issue.

Then No CONFIG_GPIO_AS_PINRESET was defined in my code. we don't use reset (p0.18) pin in our project.

and then I did it with using "nrfjprog --recover" and "nrfjprog --eraseall"

but they fails and give us the following errors.

C:\Program Files\SEGGER\JLink_V794e>nrfjprog --recover
[error] [ Client] - Encountered error -102: Command connect_to_emu_with_snr executed for 316 milliseconds with result -102
ERROR: Unable to connect to a debugger.
[error] [ Worker] - An unknown error.
ERROR: JLinkARM DLL reported an error. Try again. If error condition
ERROR: persists, run the same command again with argument --log, contact Nordic
ERROR: Semiconductor and provide the generated log.log file to them.
NOTE: For additional output, try running again with logging enabled (--log).
NOTE: Any generated log error messages will be displayed.

C:\Program Files\SEGGER\JLink_V794e>nrfjprog --eraseall
[error] [ Client] - Encountered error -102: Command connect_to_emu_with_snr executed for 399 milliseconds with result -102
ERROR: Unable to connect to a debugger.
[error] [ Worker] - An unknown error.
ERROR: JLinkARM DLL reported an error. Try again. If error condition
ERROR: persists, run the same command again with argument --log, contact Nordic
ERROR: Semiconductor and provide the generated log.log file to them.
NOTE: For additional output, try running again with logging enabled (--log).
NOTE: Any generated log error messages will be displayed.

So, any advice for us?

RE: connection fail via swd with jlink

Menon — Tue, 04 Mar 2025 12:36:38 GMT

Hello,

Please check this old DevZone case and see if it is relevant: https://devzone.nordicsemi.com/f/nordic-q-a/68959/programmation-error-due-to-reset-pin

Kind regards,
Abhijith

RE: connection fail via swd with jlink

bini2007 — Tue, 04 Mar 2025 07:55:49 GMT

I don't know which SDK and version. but I used "s113_nrf52_7.2.0_softdevice.hex" in our project starting on 2021.01.27.
and I cannot open old DevZone thread you suggested before. please check this and again give me a link.

In addition, our program is a old custom application and already on mass production. However, there are problems on our project so I am involved with it, currently. so I don't know the development history well. a

Anyway, it's my conditions for this project.

Our old project is running well under the DFU for fw update using nRF connect for mobile app.

Here, apart from DFU, I'd like to debug our target via jlink debugger (swd) and see the RTT logs from our target.

Then RTT viewer give me the error.

The error log are as followings, again:

LOG: J-Link RTT Viewer V7.94e: Logging started.
LOG: Connecting to J-Link via USB...
LOG: Device "NRF52833_XXAA" selected.
LOG: InitTarget() start
LOG: InitTarget() end - Took 2.52ms
LOG: RESET (pin 15) high, but should be low. Please check target hardware.
LOG: Failed to attach to CPU. Trying connect under reset.
LOG: RESET (pin 15) high, but should be low. Please check target hardware.
LOG: RESET (pin 15) high, but should be low. Please check target hardware.
LOG: RESET (pin 15) high, but should be low. Please check target hardware.
LOG: RESET (pin 15) high, but should be low. Please check target hardware.
LOG: RESET (pin 15) high, but should be low. Please check target hardware.
LOG: Connect fallback: Reset via Reset pin & Connect.
LOG: RESET (pin 15) high, but should be low. Please check target hardware.
LOG: InitTarget() start
LOG: InitTarget() end - Took 3.22ms
LOG: RESET (pin 15) high, but should be low. Please check target hardware.
ERROR: Could not connect to target device.

This error seems to be same when not connected with target device with jlink debugger.

Then please help me how to solve this problem.

RE: connection fail via swd with jlink

Menon — Mon, 03 Mar 2025 13:21:34 GMT

Hello,

Which SDK and version are you using to build your application? Take a look at this old DevZone thread discussing a similar issue. Please see if this discussion has any relevance to your issue.

How did you program your first software? You mentioned that your program is running well. I assume this is a custom application. Have you tried any applications inside the SDK, and do they produce the same issue?

Kind Regards,
Abhijith

RE: connection fail via swd with jlink

bini2007 — Sat, 01 Mar 2025 08:14:05 GMT

In addition to above,

We also see RESET pin (p0.18) that can be a gpio. We don't use this RESET pin and it seems to not be used in our software too.
Our software use dfu, currently.