Unresponsive Kinetis

[leifzars]

I find my K20 unresponsive from time to time. The device should be running continuously, but it seems to halt. Then when I hook a JTag to the chip I am unable to read memory or view any state.

The only way I can recover the K20 is by power cycling the chip right before i try and re program it. So I have no way of determining how it go into this state. Not even the WDOG resets it.

What could be happening? And ideals ?

[jeremyzhou · Accepted solution]

Hi Leif Zars,

According to the screenshot, I think the root cause of the issue is the power supply.

The MCU can't work when the voltage of power supply is 0.

Have a great day,
Ping

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[leifzars]

Thanks, so simple.

[scottm]

The watchdog's not resetting it?  Have you tried inserting an infinite loop to double check that the watchdog is working properly the rest of the time?

If it is, I'd look next at your clock source and your power supply and make sure they're both stable.

Are you running from flash or from RAM?  If you're running from RAM then I suppose a bug that's trashing your memory contents isn't going to be able to be reset by the watchdog.

Scott