i.MX ProcessorsのトピックFRDM-IMX8MPLUS: System resets immediately when connecting Lauterbach TRACE32.

FRDM-IMX8MPLUS: System resets immediately when connecting Lauterbach TRACE32.

neko — Wed, 03 Jun 2026 15:17:29 GMT

Hi NXP Community,

I am working with the FRDM-IMX8MPLUS development board and trying to debug it using a Lauterbach TRACE32 via the 10-pin JTAG interface.

I am encountering a severe issue: the system resets/powers off immediately the moment I plug the JTAG cable into the board while it is running.

I try to execute SYStem.Mode Attach in the TRACE32 software, it fails and returns the error: debug port time-out at UNKNOWN.

I suspect this behavior is tied to the Cold Reset signal path. Before connecting the debugger, both VTREF (Pin 1) and JTAG_RESET (Pin 10) are stable at 1.8V. Upon plugging in the TRACE32, JTAG_RESET instantly drops to 0V, which coincides with VTREF falling to 0.7V and crashing the system (the green led turn off).

How can I properly configure the hardware/software to avoid the reset issue and successfully attach the debugger?

Thanks in advance!

Re: FRDM-IMX8MPLUS: System resets immediately when connecting Lauterbach TRACE32.

JosephAtNXP — Wed, 03 Jun 2026 17:21:49 GMT

Hi,

Thank you for your interest in NXP Semiconductor products,

Could you please try connecting TRACE32 before target POR?

Regards

Re: FRDM-IMX8MPLUS: System resets immediately when connecting Lauterbach TRACE32.

neko — Wed, 03 Jun 2026 17:59:02 GMT

Hi Joseph,

I am following these steps:

Power off the IMX8MP board and connect Trace32.
Power on the board.

However, the board does not boot. There is no output on the serial UART, and LED D16 does not turn on.

If I disconnect Trace32, the board boots successfully again.

Regards,

Re: FRDM-IMX8MPLUS: System resets immediately when connecting Lauterbach TRACE32.

neko — Wed, 03 Jun 2026 18:09:08 GMT

Hi,

I also attach images of the board when Trace32 is plugged in and when it is unplugged.

Regard