F28M35H52C: EXternal watchdog reset during debugging

Ril Dank

Part Number: F28M35H52C

Hello,

We have a custom board with a F28M35H52C micro controller and an external watchdog that will reset the MCU if its input is not toggled within 1s. The watchdog is configured to be enabled only after we start toggling its input.

Once the watchdog is enabled, it seems not possible to debug or program the MCU with the XDS200 probe as the watchdog keeps resetting the MCU.

Is it normal behavior and is it possible to "ignore" the reset pin when the debug probe is connected ?

Thanks for the help.

Ril

over 7 years ago

0 Hareesh Janakiraman over 7 years ago

TI__Guru* 95315 points

Who is "feeding" the external Watchdog? Why does it keep resetting the MCU?

0 Vivek Singh over 7 years ago in reply to Hareesh Janakiraman

TI__Guru** 116601 points

On your other query -

Is it normal behavior and is it possible to "ignore" the reset pin when the debug probe is connected ?

No, toggle on reset pin can not ignore. You can not debug the device with reset pin low. You need to find out why watchdog is getting triggered. You should disable the external watchdog and then debug the device.

Regards,

Vivek Singh

0 Ril Dank over 7 years ago in reply to Vivek Singh

Intellectual 455 points

Hello guys, thanks for answering.

Who is "feeding" the external Watchdog? Why does it keep resetting the MCU?

The MCU is feeding it. Once enabled, the watchdog will keep asserting the reset pin every 1 second.

This is not a problem for now because the watchdog will not be enabled until we start toggling its input.

Vivek Singh said:

No, toggle on reset pin can not ignore. You can not debug the device with reset pin low. You need to find out why watchdog is getting triggered. You should disable the external watchdog and then debug the device.

Ok I understand. I was asking the question because I thought it was pretty standard to have such an external watchdog that is always active. And so I was wondering how people usually do to handle this.

I suppose we can delay the activation of the watchdog at boot up, so we can still use the debugger to program the MCU if needed...

Thanks for the help.

Ril

C2000™︎ microcontrollers

C2000 microcontrollers forum

F28M35H52C: EXternal watchdog reset during debugging