Unable to connect to target I.MX8MPLUS

Hi,

When I am trying to detect my target platform  for i.MX8Mplus processor using the ARM Development Studio v2025.0-1 . I am getting prints like this

[23/09/25 12:02:59] Arm Development Studio v2025.0-1, build number 2025010903

[23/09/25 12:02:59] JTAG Clock Speed : 7500000Hz

[23/09/25 12:02:59] Beginning Autodetection

[23/09/25 12:03:00] --- --- ---

[23/09/25 12:03:00] Connected to Debug Probe

[23/09/25 12:03:00] --- --- ---

[23/09/25 12:03:00] --- --- ---

[23/09/25 12:03:00] Counting devices:

[23/09/25 12:03:00] DR Chain [136]:

00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

00000000

[23/09/25 12:03:00] Device Count: 136

[23/09/25 12:03:00] Detected number of devices = 136, maximum allowed = 128. This problem is usually a result of the scanchain not acting correctly when using JTAG scans to count the number of devices.

[23/09/25 12:03:00] Performing legacy SWD->JTAG switch

[23/09/25 12:03:00] Counting devices:

[23/09/25 12:03:00] DR Chain [136]:

00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

00000000

[23/09/25 12:03:00] Device Count: 136

[23/09/25 12:03:00] Performing Dormant Mode SWD->JTAG switch

[23/09/25 12:03:00] Counting devices:

[23/09/25 12:03:00] DR Chain [136]:

00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

00000000

[23/09/25 12:03:00] Device Count: 136

[23/09/25 12:03:00] --- --- ---

[23/09/25 12:03:00] Disconnected from Debug Probe

[23/09/25 12:03:00] --- --- ---

[23/09/25 12:03:05] JTAG detection failed, trying SWD

[23/09/25 12:03:05] WARNING - Multi-drop SWD is not supported, a single DAP on the scanchain has been assumed.

[23/09/25 12:03:05] The scanchain must be built manually if more scanchain devices are present.

[23/09/25 12:03:07] --- --- ---

[23/09/25 12:03:07] Disconnected from Debug Probe

[23/09/25 12:03:07] --- --- ---

[23/09/25 12:03:07] --- --- ---

[23/09/25 12:03:07] Disconnected from Debug Probe

[23/09/25 12:03:07] --- --- ---

[23/09/25 12:03:07] Unable to connect to device ARMCS-DP

  • Hi

    My name is Stephen and I work at Arm.

    It looks like you are trying to use the Platform Configuration Editor (PCE) auto-detection feature.
    Arm DS has a ready-made debug configuration for the NXP i.MX8Mplus, so there is no need to use the PCE auto-detection feature.

    To access the ready-made debug configuration for the NXP i.MX8Mplus, use 
    Run > Debug Configurations, select Generic Arm C/C++ Application > New launch configuration.  In the filter, enter "i.MX8Mplus".
    See screenshot.



    "Unable to connect to device ARMCS-DP" means the debugger is not able to the CoreSight Debug Port.  This might be because it is not powered-up.  The NXP i.MX8Mplus has quite a complex power-up/start-up sequence, requiring the Cortex-M7 to run some code to power-up the Cortex-A53s.  When booting into Linux, this is normally all done for you, so try booting into Linux first, and then connecting.

    If that still doesn't work, try lowering the JTAG clock frequency.

    If your target has booted into Linux, but you still can't connect, perhaps Linux has turned off the debug clocks in order to save power.  Try power-cycling the target, and halting it at the (u)boot prompt, then try reconnecting.

    Which debug probe are you using - e.g. a DSTREAM-ST?

    Hope this helps

    Stephen

  • Yes We are using DSTREAM-ST .

    In debug configuration we are detecting DSTREAM-ST  .

    What you send the screen shot ,in that after selecting the I.MX8MPLUS EVK in baremetal.

    After this  in connection tab setting the lower frequency(1MHZ) and also DStream detecting ,in debugging tab enable Connect only  but after click on debug we are getting failed to connect to any devices on the target. Check that the target is correctly connected to the debug probe and powered on .