JTAG Debugging: Verdin iMX8M plus -- What can be accessed?

Technical Support
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Hello Toradex Support Team,

I’ve been working with the Dahlia carrier board for the Verdin iMX8M plus, and am wondering what chips can be accessed through the JTAG header, and how this may be done. Does it access the M7 core, the A53 cores, or both? If it is both, how could I choose which core to target?

Thanks,
Andrew

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Hello Andrew,

Thank you for your question about the JTAG interface on the Dahlia carrier board with the Verdin iMX8M Plus module.

The Dahlia board provides a JTAG interface via the X8 header. The JTAG signals usually operate at 1.8V, and you should ensure that jumper JP6 is open when using an external debugger with the X8 header [Dahlia Carrier Board Reference].

Regarding your specific questions:

  • The JTAG connector allows for hardware-level debugging and, in general, can provide access to the CPU cores present on the SoC. On the Verdin iMX8M Plus, this could include both the Cortex-A53 (application cores running Linux) and the Cortex-M7 (real-time core).
  • However, the publicly available documentation does not explicitly state which cores (A53, M7, or both) can be targeted via the JTAG pins. The JTAG interface physically connects to the SoC, whose internal debug logic generally enables access to all cores. Selecting which core to debug is typically performed through your debug probe’s software (e.g., with OpenOCD or a proprietary tool), where you can select the target core in your configuration.

In summary:

  • The JTAG header accesses the SoC debug interface.
  • You should be able to target the Cortex-A53 cores, the Cortex-M7 core, or both, depending on your debugger and software configuration.
  • Core selection is typically managed via your debugger settings and software when initiating a debug session.

For detailed instructions, refer to your specific debugger’s documentation and ensure any voltage level or jumper requirements are respected as per the Dahlia carrier board documentation [JTAG interface info].

Best regards,
Toradex AI Assistant.

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Hi @aweaver

Check this page.

Also, if your objective is to just access the M7 and A53 serial terminal, you can use the USB-C port.

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All set here Andrew?

Best regards,

Michael Park
Toradex