CCS/TIDA-01281: Olimex XDS100v3/TMS320F28035 - SC_ERR_PATH_BROKEN

Thomas,

The problem is described in additional detail at:

http://software-dl.ti.com/ccs/esd/documents/ccsv7_debugging_jtag_connectivity_issues.html#invalid-data-read-back 

Thomas Albrecht46 said:

- Is this what it is supposed to look like?

As you can tell from the reference above, the error is located between the Debug Probe and the target, thus the host PC drivers are correctly instantiated.

Thomas Albrecht46 said:

- Under target configs I've chosen the "Texas Instruments XDS100v3 USB Debug Probe_0". If I am corrent the emulator type is not available anymore. So this should be right?

I don't quite understand what you mean by this sentence. Could you attach your .ccxml or a screenshot of your configuration?

Thomas Albrecht46 said:

- Next step for me would be checking the physical signals of the jtag. Is there anything significant? Pull-Ups/downs?

The best reference to use is below:

http://software-dl.ti.com/ccs/esd/documents/xdsdebugprobes/emu_xds_target_connection_guide.html 

Thomas Albrecht46 said:

- Is it legitimately to check the "xclkout" to know whether the controller is working properly? Should I see a sine or a square clock?

Certainly, especially to check for noise on the ground or the JTAG lines. The post below shows some waveforms of a connection between a XDS100v1 and a F28x device:

https://e2e.ti.com/support/development_tools/code_composer_studio/f/81/p/661170/2442314#2442314 

Hope this helps,

Rafael

Hi Rafael,

thanks for your answer and the links. I am checking them at the moment.

Respective the configuration of the connection. This is what it looks like.

I've read that in the CCS 5.x there was an option to use instead of "Texas Instruments XDS100v3 USB Debug Probe" . I am just concerned that I have the troubles because the debugger is not directly from TI.

I let you know whether I find a solution.

Thank you very much

Best regards,

Thomas

Hi Rafael,

I am not quite sure whether I am mistaken something but I still get the same error. However please check the settings I made. This means that at least one problem might be resolved. I can only choose "Fixed default 1.0Mhz frequency" when I choose above the setting "mimic XDS100v2 as shown below:

If I do not choose "mimic XDS100v2" under "The Converter Usage" I cannot select "Fixed default 1.0Mhz frequency.

Thank you very much so far

Best regards,

Thomas

Thomas,

Please apologize for the delay; yes, the option is correct as the XDS100v3 is a superset of the XDS100v2 and therefore this was certainly a problem.

Another detail that may be getting in the way of a good connection: I also have an Olimex XDS100v3 and, if you are using its 20-pin cable adapter, it needs to be connected in a specific order to properly work. This is shown at:
e2e.ti.com/.../1492782

If you are using the 14-pin connector instead, then any straight through cable should work, although you need to be careful to properly align the pinout. My XDS100v3 does not have the pin 6 removed on the 14-pin header as recommended by the TI standard.

software-dl.ti.com/.../emu_jtag_connectors.html

Hope this helps,
Rafael

Hi Rafael,

thanks for your endurance.

I am using the 14Pin Connector. I have revision D of the olimex. If I interpret the user manual correct this bug should be fixed. So Pin 6 is open.

At the moment I am not quiet sure whether my board /TIDA-01281 might be the problem. I am seeing the 20Mhz crystal but no clock at the CLKOUT(PIN33) of the TMS320F28 although I removed a pull-up which was connected to the pin. Do you think it might be a problem with the controller/board itself or would I see another error if this would be the case?

Thank you very much,

Best regards,

Thomas

Thomas,

Thomas Albrecht46 said:

I am using the 14Pin Connector. I have revision D of the olimex. If I interpret the user manual correct this bug should be fixed. So Pin 6 is open.

Thanks for the clarification.

Thomas Albrecht46 said:

I am seeing the 20Mhz crystal but no clock at the CLKOUT(PIN33) of the TMS320F28 although I removed a pull-up which was connected to the pin.

Now I understand what you mentioned in your original post about XCLKOUT; certainly the error message would be thrown if the device is "dead".

Since this pin can be multiplexed with other functions, I checked the device datasheet. If the device is blank this multiplexer will probably be set to its default state which, if I read it correctly, that is the GPIO18 and not the XCLKOUT function (check the GPAMUX2 register). In this case, checking this pin does not help much at this stage, unless you know the device is already programmed.
I would check the XRS and TRST pins to see if they are, in fact, pulled up. They would also prevent either the normal operation of the device or the JTAG from properly working.

According to the Target Configuration guide, I can't quite understand why TDO is pulled up, but given it is a 10kΩ resistor it shouldn't load this line too much.

software-dl.ti.com/.../emu_xds_target_connection_guide.html

The other obvious details to check are power supply voltages and integrity, proper GND issues and loops, etc.

Hope this helps,
Rafael

A continuation of this discussion with a final solution is posted at:
e2e.ti.com/.../711186