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Why will my K64F code only start with OpenSDA cable connected?

Question asked by E Engineer on Nov 30, 2016
Latest reply on Dec 4, 2016 by Hui_Ma

I am trying to move my K64F board code so it will start at power up. At present, the only way I can get it to run is to plug a USB cable into the OpenSDA port (even if the other end of the cable goes to a non-debug PC). Once the program is running, I can unplug it and the program continues to run.

 

The target MCU reset signal seems to be negated with the cable disconnected, so I don't think it is being held in reset. My power is via the 5-9V input on J3, and 3.3Vdc seems to be present even without the USB cable connected. I'm not clear on what connecting the OpenSDA cable does that starts the code...?

 

I have tried cutting the J7 copper trace on one board to completely disable OpenSDA. Seems to make no difference.

 

Code compiled with the debug configuration should run even without the debugger connected, shouldn't it?

 

I am using the latest releases of tools, KDS 3.2, SDK 2.0, OpenSDA 0226.

 

The little discussion I find of release vs. debug has to do with much older tools. The way information is presented on this site, it doesn't seem anything is ever updated to reflect changes to tools, even though there have been some immense changes. For example, there is a discussion of start up problems due to capacitor C75 on early versions of the K64F board; all of my boards are rev E3, yet the discussion has never been updated to reflect that problem should be resolved because that cap went away.

 

Where, in fact, is there any documentation for use of the release/debug configurations in KDS 3.2? There are many settings under the debugger and startup tabs of debug configurations which seem to have no documentation beyond some pop up tips obtained by pointing at them. That hardly counts as documentation!

 

I would appreciate suggestions, but I also suggest some useful applications information should be created and kept up to date on this topic, since it seems everyone starting with the K64F is going to get to this point sooner or later.

 

Thanks.

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