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Watchdog timer selection for Project

sireevenkat1
Senior

Hi,

I am using STM32G491RE for my product. I want to implement watchdog timer functionality. In the data sheet we have IWDT and WWDT. Which one is best for real time products and I am using HSE for clock. I am planning to use watch dog timer reset time in seconds.
For IWDT in the document mentioned programmable timeout range is 125usec to 32.8 sec.
For WWDT how can I calculate the maximum timeout range?? My APB1 clock is 96MHz.
For OTA update, Does watchdog timer effect the functionality??
Disabling the watchdog timer in bootloader code is enough for the watchdog timer not interfacing with the update process??
Can anyone suggest.
Thanks

2 REPLIES 2
TDK
Guru

There is no general "best". Otherwise why have multiple? The best one for your application depends on the needs of your application. There is much overlap between the two and if you're just looking for a general watchdog, either will suffice. If you want a long timeout, IWDG is probably better.

Here are the maximum timeout values for WWDG given in the datasheet. In general, much shorter durations than IWDG. Adjust for your PCLK.

TDK_0-1724243291668.png

Watchdog cannot be disabled once started. You need to reset the chip to disable, or continue to reset the watchdog in the bootloader.

(Note: They are called IWDG and WWDG.)

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Joe WILLIAMS
ST Employee
Hi sireevenkat1 This post has been escalated to the ST Online Support Team for additional assistance. We'll contact you directly. Kind Regards Joe STMicro Support