CCS/TM4C123GH6PM: CCS/TM4C123GH6PM

Gondos Andor

Part Number: TM4C123GH6PM

Tool/software: Code Composer Studio

Hello,

I have a self-designed pcb, that use TM4C123GH6PM microcontroller and this works with 24V. I use TI XDS110 Debug Probe connection.

My settings:

And the test connection:

What can be the problem?

Regards,

Andor

over 5 years ago

0 Bob Crosby over 5 years ago

TI__Guru 72500 points

Check your power and grounds on the TM4C (Vdd and GND). Vdda must also be supplied even if the AtoD is not used. Measure the 1.2V on the Vddc supply (pins 25, 56). Make sure the RST- pin is high. If you have a main crystal on your board, verify it is working by looking at the waveform on pin 41.

0 Gondos Andor over 5 years ago in reply to Bob Crosby

Prodigy 160 points

Hi Bob,

I checked my power and grounds, and these are goods, but the test connection show the same error.

Do you have any idea?

Thanks,

Andor

0 Bob Crosby over 5 years ago in reply to Gondos Andor

TI__Guru 72500 points

Did you measure the 1.2V on the Vddc supply (pins 25, 56)? Did you make sure the RST- pin is high. Did you verify if your main crystal isworking by looking at the waveform on pin 41?

If all of this checks out, use a scope and verify the waveform at TCK(52), TMS(51) and TDO(49) while running "Test Connection". Then look to see if you have an output on TDO(49) and trace that it goes back to your XDS110 connection.

0 Gondos Andor over 5 years ago in reply to Bob Crosby

Prodigy 160 points

Yes, i checked Vddc, RST-pin.

Now I verified the main crystal, TCK, TMS, and TDO. These are the results:

Main crystal:

TCK:

TMS:

TDO:

TDO at programming connector:

These are goods?

Regerds,

Andor

0 Bob Crosby over 5 years ago in reply to Gondos Andor

TI__Guru 72500 points

It is hard for me to tell. It looks like you changed the vertical gain on the different scope pictures. Also, these signals look AC coupled. Is the GND of the XDS110 attached to the GND of your board? Did you ground the scope probe when taking these pictures?

0 Gondos Andor over 5 years ago in reply to Bob Crosby

Prodigy 160 points

Yes, the XDS110 atteched the GND, and i ground th scope probe.

Regards,

Andor

0 Bob Crosby over 5 years ago in reply to Gondos Andor

TI__Guru 72500 points

Then from the scope pictures, there appears to be a problem with your ground connections. All of the JTAG signals should go from GND to about 3V. They should never drop below ground.

0 Gondos Andor over 5 years ago in reply to Bob Crosby

Prodigy 160 points

I checked my grond connections, and I dont't found problem.

Best Regards,

Gondos Andor

0 Gondos Andor over 5 years ago in reply to Bob Crosby

Prodigy 160 points

My target configuration is good?

Regards,

Andor

0 Bob Crosby over 5 years ago in reply to Gondos Andor

TI__Guru 72500 points

Can you explain why the scope pictures appear to show all of the JTAG signals centered around ground? Is that a scope setup? It appears to say you are correctly DC coupled. Do you understand my concern?

0 Bob Crosby over 5 years ago in reply to Gondos Andor

TI__Guru 72500 points

Yes, the target configuration looks good unless you have added any other devices onto the JTAG scan chain. Can you share the schematic showing the JTAG connector and the connections to the TM4C123?

0 Gondos Andor over 5 years ago in reply to Bob Crosby

Prodigy 160 points

Of course

Programming connector:

And the connections to TM4C:

Best Regards,

Andor

0 Bob Crosby over 5 years ago in reply to Gondos Andor

TI__Guru 72500 points

For completeness could you add the TM4C_SchDoc so that I can verify which pin you connected to. I am concerned about your n_TRST and TVDD connections since those are not pin names on the TM4C123 device.

Also, on the schematic that I use, pins 2 and 10 of P3 (the JTAG connector) would be connected together but not connected to GND if drawn as you show them. Can you verify in the layout that they really did connect to ground?