We are running a survey to help us improve the experience for all of our members. If you see the survey appear, please take the time to tell us about your experience if you can.
Hi Frnds,
Can a Interrupt Service Routine be serviced even when Micro controller hangs for undue reasons??
what is a hang in Microcontroller means????
Thanx for u kind reply.
I am servicing watchdog timer in Interrupt, I am using a External watchdog timer, Max691 where it has to be serviced within 1.5secs , so how is this programmed if at all watchdog timers should not be serviced in interrupt????
"I am servicing watchdog timer in Interrupt"
And now you know why that's a really bad idea! (but see below)
The idea is that the Watchdog should be restarted if and only if the software is running correctly.
Therefore, you should put your Watchdog restarts at a point in your code that is always reached when it's running properly, but won't be reached if anything hangs.
Typically, this would be in your main loop.
If you do have some operations that you know can take longer than the watchdog interval, you will have to either split them, or think of some solution.
One way to extend the watchdog period does use an interrupt: Instead of restarting the watchdog directly, your main code restarts a global counter variable; The timer interrupt then decrements the variable, and only restarts the watchdog if it is above some limit...
www.ganssle.com/watchdogs.pdf www.ganssle.com/.../tem105.pdf
Thanx andy.,
i will go through the document and find som solution for watchdog timer..,