FreeRTOS and watchdog

Ankush Khare85

Hello experts !!!

I have been working on FreeRTOS and know that tick time has the highest priority.
So I have a doubt whether watchdog timer is useful in FreeRTOS or not ?

Specially if we are creating several tasks, then how much is the importance of watchdog ?

over 10 years ago

0 Charles Tsai over 10 years ago

TI__Guru**** 191886 points

Hi Ankush,

If you don't service the watchdog in time, it can generate a reset to the CPU which is the highest exception.

0 Ankush Khare85 over 10 years ago in reply to Charles Tsai

Intellectual 800 points

Hi Charles,

My doubt is regarding the necessity of watchdog in FreeRTOS.
Do we need watchdog in FreeRTOS if we create several tasks ?

0 Charles Tsai over 10 years ago in reply to Ankush Khare85

TI__Guru**** 191886 points

Hi Ankush,

Watchdog serves a different purpose than the RTI which is used by the OS. The watchdog timer is used to detect and recover from malfunctions in the device.The malfunctions could be due to hardware faults or software faults. For example, you are fetching data from the flash and if there is a fault in the flash controller and never replies the data and in doing so it keeps the CPU in wait states. This results in the CPU hanging. An interrupt caused by an OS tick is not sufficient to break the CPU from hanging because the on going read transaction from the flash has not completed yet. You need a watchdog when the timer expires it will reset the CPU.

Arm-based microcontrollers

Arm-based microcontrollers forum

FreeRTOS and watchdog