I'm bit new with using applications that use watch dog timers and i'm up to use one for the first time. I'm using pic18f26j50 and it got an internal watch dog timer which got a limit from 2ms and can be expanded up to 2 minutes.

I understand the whole purpose of using internal watch dog timers is to prevent any accidental code lock.So i would like to know what are the ways in which the watch dog timer can be tested and proved that it could be fail safe to kick it properly with out any error.

I trust input from you will help me to write test routines so that i could understand the features of it and also i would like to be informed about any possible pitfalls if any.

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> And i trust watch dog is usually cleared inside the main and another
>  question that suppose i have is if i have certain modules A,B,C..N
>  that gets called in main. What are the requirements for a designer
>  such that watch dog timer implemented meets the standard and what are
>  the things which the developer must look in to properly in such a
>  case.
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