Watchdog Timer Usefulness

[imranahmed]

Let me know that what is the Watchdog Timer and what its purpose in microcontrollers.
Can anyone interested to tell me about it?

 

[barry]

If the software is running properly, it will trigger the watchdog timer periodically. If the software has 'hung' it won't generate the watchdog triggers, and the watchdog timer will timeout and reset the processor.

 

[imranahmed]

OK I understand.

 

[imranahmed]

Please let me know if I do enable or disable Watchdog Timer in uC or in my PIC12F683,what effect in the performance
of PIC12F683 will do?

 

[alexan_e]

A watchdog it just a timer running, if you don't reset it in the given period then it will reset the mcu.

There is no performance penalty except from a line that needs to be added in the code to resets the watchdog but the effect is like non existing

 

[bigdogguru]

Another common use of the watchdog timer is to wake a microcontroller from a "sleep" mode.

The technique is often utilized to conserve battery power, the microcontroller is periodically awaken to perform a specific task(s) and then put back to sleep.

The period or time interval of the sleep state can be controlled by the watchdog timer.

Reference: PIC12F683 Datasheet, Section: 12.0 SPECIAL FEATURES OF THE CPU, Page: 83

The Sleep mode is designed to offer a very low-current
Power-down mode. The user can wake-up from Sleep
through:

• External Reset

• Watchdog Timer Wake-up

• An interrupt

BigDog