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How to disable WDOG on FRDM-KE04Z board?

Question asked by Dale Wheat on Jan 2, 2017
Latest reply on Jan 4, 2017 by Dale Wheat

I'm trying to disable the watch dog timer (WDOG) on the FRDM-KE04Z board.  My code writes a 0x00 to the WDOG_CS1 register right after boot and even reads it back and confirms it as 0x00 to verify the write occurred.

 

However, the chip resets predictable about 4ms later with a '1' in the WDOG bit of the SIM_SRSID register, telling me that the reset was caused by a watchdog timer event.

 

If I add a watchdog reset sequence to my wait loops, the problem goes away, but I'd rather just turn the WDOG off altogether and have it stay off.

 

I've read everything I can find on the WDOG, including the device reference manual and many examples for other Kinetis devices.

 

If I single-step my program using the debugger, it works fine.  It's only when I let it free-run from either a power-on or from pressing the reset button on the board that the WDOG fires.

 

Any ideas what I might be doing wrong or overlooking?  Any help is appreciated.

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