Contents
What is AVR watchdog?
AVR® devices have an Enhanced Watchdog Timer (WDT) that runs on a separate oscillator from the main instruction clock. The WDT is essentially a counter that increments based on the clock cycles of an on-chip 128kHz oscillator. If the system doesn’t restart the counter, an interrupt or system reset will be issued.
What is the function of watchdog timer internal or external?
A watchdog timer (WDT) forces an embedded microprocessor or microcontroller to reset (hardware reset) in response to an invalid software state. Such states can be as simple as a toggled register bit caused by a software bug, a cosmic ray, or an event such as EMI (electromagnetic interference).
How to use the AVR watchdog you AVR Freaks?
I have never worked with the watchdog and before I start asking a lot of questions that most likely will be answered in a tutorial I want to have read that first. Calculate you max execution time in main and select an appropriate WDT timeout. Just before you go into your While loop start the WDT, and put a WDT Reset at the end of the loop.
Which is the watchdog mode in avr2560v?
I am going through datasheet of AVR2560V. In page 65 , table 12-1, it says that AVR2560 has 3 mode for watchdog This means if we want to use watchdog timer as source of Interrupt, then i should disable WDE.
What’s the default timeout for Watchdog timers?
Jack Ganssle has written some nice documentation / tutorials about effective use of watchdog timers. Note the default value of the WDT is 16ms on most mega’s, so if you use a longer period, be sure you handle the timeout pretty quickly in your start up code as a reset will ‘reset’ your timeout to this short period!
How do you reset the AVR while loop?
Just before you go into your While loop start the WDT, and put a WDT Reset at the end of the loop. As long as your code hits the reset the WDT will stay in its doghouse, if the reset is not hit the WDT will bark and reset the AVR.