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Old 7th January 2004, 09:01 AM   (permalink)
Default WDT

what is WDT on pic microcontroller?
give some application examples
finst is offline  
Old 7th January 2004, 09:47 AM   (permalink)
Default Re: WDT

Quote:
Originally Posted by finst
what is WDT on pic microcontroller?
give some application examples
The original use of a WDT is to reset the device in case it 'locks up', you include CLRWDT instructions at regular intervals through out your program, which must occur more often than the WDT time out interval.

If the program crashes, or gets stuck in an endless loop, the CLRWDT instructions won't get executed - so the WDT then resets the chip (this obviously requires no CLRWDT instructions in the endless loop it's stuck in, you need to use them carefully).

It's also commonly used to wake a PIC from sleep, this extends battery life considerably - wake up, check what it needs to, go back to sleep again. As the WDT is just a free running oscillator it's not very accurate, so you can't use it for timing purposes - but one interesting application (in a MicroChip application note) is using the WDT to measure temperature, it's oscillator is temperature dependent, so it can be used to measure temperature changes.
Nigel Goodwin is online now  
Old 7th January 2004, 12:35 PM   (permalink)
Default Re: WDT

Quote:
Originally Posted by Nigel Goodwin
Quote:
Originally Posted by finst
what is WDT on pic microcontroller?
give some application examples
The original use of a WDT is to reset the device in case it 'locks up', you include CLRWDT instructions at regular intervals through out your program, which must occur more often than the WDT time out interval.

If the program crashes, or gets stuck in an endless loop, the CLRWDT instructions won't get executed - so the WDT then resets the chip (this obviously requires no CLRWDT instructions in the endless loop it's stuck in, you need to use them carefully).

It's also commonly used to wake a PIC from sleep, this extends battery life considerably - wake up, check what it needs to, go back to sleep again. As the WDT is just a free running oscillator it's not very accurate, so you can't use it for timing purposes - but one interesting application (in a MicroChip application note) is using the WDT to measure temperature, it's oscillator is temperature dependent, so it can be used to measure temperature changes.
Thanks for your reply, it is useful to me
finst is offline  
Old 23rd August 2007, 09:28 PM   (permalink)
Default timer

dear friends !

i want to create a delay of 70ms using 16 bit timer 1 in avr using assembly language how can i do this plz help
rshafi68 is offline  
Old 23rd August 2007, 09:50 PM   (permalink)
Default

hey, great choice of a thread to respond to. not. Too bad you chose an inappropriate thread but worse, it's just bad form to hijack a thread with your question.
philba is offline  
Old 24th August 2007, 01:21 AM   (permalink)
Default

You resurrected a dead thread from more than 3 YEARS ago, and it doesn't even have much to do with your question. Never do this. If you have a question, just ask it.
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