External Hardware Watchdog

The hardware watchdog is in the microcontroller integrated on the board or of developed micro module or an external microelectronic component with communication with the microcontroller.

External hardware watchdog. In these cases the design should be augmented with external hardware that monitors system operation and issues a reset if needed. 1 like scruffr april 3 2018 12 53pm 5. This is where an external hardware watchdog may be a better choice. By jonfrei in circuits arduino.

In case of time out watchdog the microcontroller must elapse a predetermined time before the watchdog reports. Using a hardware timer as a watchdog will ensure that it will fire if something stalls vs the application watchdog but doing a software reset is not the same as a hardware reset. The watchdog interrupt wdi input is a signal generated by the host processor to notify the external wdt that it is working properly. External wdts few microprocessors as opposed to microcontrollers have an internal watchdog timer and in many cases internal wdts do not provide the reliability needed for a particular application.

External watchdog timer ics are more expensive and should therefore be used for critical systems that need higher reliability. A high to low transition within everynseconds specified by thetimeoutselection value keeps the external wdt from resetting the host processor.