Cannot debug FDRM-K64F via J-link.

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Cannot debug FDRM-K64F via J-link.

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Contributor II

I am using a FDRM-K64F board and I cannot debug with MCUXpresso IDE via J-Link (USB). I get a "Cannot get Jtag device" error. It worked fine with the Kinetis Designer IDE. The debug configuration is set to SWD.

Any idea what the problem can be?

8 Replies

191 Views
Contributor II

Thanks. This helped. Deleting all existing launch configs was important for autodetect. Now, it detects the J-Link and it is working. :-)

I did this the first time (in Quickstart Panel) and autodetect went wrong for J-Link for some reason. Now, this second time autodetect went right. When I look at the debug launch config nothing is different with the first attempt. Must be some hidden setting that went wrong.

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191 Views
Senior Contributor II

It depends on your pin muxing and I believe there is a bit in the system control registers about it. Search for jtag in the reference manual and you should find it. Just wondering: why would you need JTAG except you would have multiple devices on the scan chain?

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NXP Employee
NXP Employee

Can you confirm how you are creating your launch configuration? With MCUXpresso IDE you really need to be using the Quickstart Panel -> Debug option to autodetect and configure the probe. If you manually created a launch config, I would suggest deleting and starting again.

See the supplied MCUXpresso IDE User Guide for more details of how to use the built in J-Link support.

Regards,

LPCXpresso / MCUXpresso IDE Support

191 Views
NXP Employee
NXP Employee

Hi Gerald,

are you using an external J-Linkk (connected to J9)? If so, it depends what debug firmware you are running on the K20/OpenSDA: if this is the mbed/CMSIS-DAP, it can interfere with the SWD signals. In that case, power the board with the K64 USB port (not with the OpenSDA one).

I hope this helps,

Erich

191 Views
Contributor I

Hi Erich Styger,

We have successfully able to load FRDM-K64F target MCU via JLink plus debugger with SWD interface using MCUexpresso. But we are not able to do it with JTAG interface.

Below is connection between FRDM_K64F and JLink Plus debugger:

pastedImage_5.png

Please suggest your view on this.

Regards,

Harsh Bhuva

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191 Views
Senior Contributor II

Is your K64F enabled for JTAG signals? Note that the JTAG pins can be disabled to only use SWD.

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191 Views
Contributor I

Hi Erich,

Whether FRDM-K64F is normally dispatched with JTAG disabled? If yes how to enable the JTAG pins for the same.

We are not doing any configuration to make JTAG and SWD enabled or disabled.

Regards,

Harsh

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191 Views
Contributor II

Hi Erich,

I am using the USB cable and I flashed the SDA to OpenSDA/J-Link. This works fine with the Kinetis IDE. This debug connection is fast but limited to 5 break points.

This morning, I’ve found out how to use the LinkServer with OpenSDA/USB. It works, but slower than using SDA/J-Link.

Gerald.

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