timer0 and WDT (timer0 is too fast when WDT is enabled)

[mutthunaveen]

Dear Board

I’m using 16F877A PIC and I'm facing this weird problem when enabling WDT.

First i wrote a code with timer0 which could create 10ms and executed.
- Code works fine and I get 10ms interval as expected

After I enabled WDT and used with approx. 2 sec (consulting close to 2 sec time in devices.h file) and restarted WDT every where possible in my code.
- After compiling and during execution I see the timer0 with 10ms is too fast and 10ms become to 40us. Too fast timer0 event occurring.

So weird.

When I disable WDT the timer0 restores to 10ms (good working).

Is there WDT and Timer0 somewhere linked or am I doing something wrong somewhere not known?

Please help me.

thank you

[Ttelmah]

Read the data sheet......

Yes on your chip, the WDT, and timer0, use a shared prescaler.
Look at:

"BLOCK DIAGRAM OF THE TIMER0/WDT PRESCALER".

The prescaler is only available or one device _or_ the other.