IMX8MP J-LINK connection issue

I’m currently conducting tests with the VerdIn i.MX8MP Q 4GB WB IT 1.1A SOM and Dahlia V1.1C products.

When trying to connect to the m7 processor using J-Link, I am experiencing a continuous rebooting issue with the system.

Below are the steps I have taken for using J-Link:

  • I have set the Dahlia board’s JP6 jumper to OPEN in order to use an external JTAG.
  • I applied the SDK_MX8MP_3RDPARTY_Patch to paste relevant data into C:\Program Files\SEGGER\JLINK to support JLink script for mx8mp.
  • I attempted to run the .\JLinkGDBServerCL.exe -if JTAG -device MIMX8ML8_M7 command to execute the JLINK debugger.

However, the system reboots, and I receive a message below.

SEGGER J-Link GDB Server V7.70c Command Line Version

JLinkARM.dll V7.70c (DLL compiled Aug 18 2022 17:30:22)

Command line: -if JTAG -device MIMX8ML8_M7
-----GDB Server start settings-----
GDBInit file: none
GDB Server Listening port: 2331
SWO raw output listening port: 2332
Terminal I/O port: 2333
Accept remote connection: localhost only
Generate logfile: off
Verify download: off
Init regs on start: off
Silent mode: off
Single run mode: off
Target connection timeout: 0 ms
------J-Link related settings------
J-Link Host interface: USB
J-Link script: none
J-Link settings file: none
------Target related settings------
Target device: MIMX8ML8_M7
Target device parameters: none
Target interface: JTAG
Target interface speed: 4000kHz
Target endian: little

Connecting to J-Link…
J-Link is connected.
Firmware: J-Link ARM V8 compiled Nov 28 2014 13:44:46
Hardware: V8.00
Feature(s): RDI,FlashDL,FlashBP,JFlash,GDB
Checking target voltage…
Target voltage: 3.29 V
Listening on TCP/IP port 2331
Connecting to target…
ERROR: Could not connect to target.
Target connection failed. GDBServer will be closed…Restoring target state and closing J-Link connection…
Shutting down…
Could not connect to target.
Please check power, connection and settings.

--------- EOM ----------------------

Are there any additional steps I need to take to debug the m7 processor using JTAG?

THank you for your kindness answer.

Hi @haegeon , did you boot up the module and stop at the u-boot terminal like explained here?

You should stop the boot process at the U-boot terminal.

Kind regards,

Thank you for the information provided.

Upon reviewing the attached video, I was able to observe that when using the U-Boot terminal to pause the booting process and then connecting J-Link, the system is seen to reboot.

Hey @vix , @Stan88 , calling you based on your experience with a JTAG with the Verdin iMX8MP in this thread.

Ever seen this behaviour from @haegeon? You guys probably have much more in-hands experience than many of us in Toradex.

Thanks a lot,

Hi @alvaro.tx,
I’ve never seen the behavior from @haegeon, but I don’t use J-Link GDB Server.
I use either J-Link Commander, or debug from Ozone.

1 Like

Hi @alvaro.tx, @haegeon
From your info I can see that you are using JLink Hardware: V8.00. It doesn’t support CortexM7. You can check it here:

I have the same situation before - I was need to upgrade my JLink JTAG to v.9 (or higher) - and problem solved.


1 Like