WWDG timeout: example calculation in RM incorrect?

[JTros.1]

In the STM32F4 Reference Manual, there is an example calculation of the WWDG timeout period t_WWDG (see attached image).

However when I type in the numbers from the example, I get a different value (87.38 ms instead of 21.85 ms). It seems that the value was calculated with WDGTB[1:0] set to 1 instead of 3.

Can someone confirm that this is correct?

[Imen.D · Accepted solution]

Hello @JTros.1​ and welcome to the STM32 Community 🙂

Thanks for pointing out this issue.

You are right, the correct value should be 87.38ms (not 21.85 ms) and the same error is also in the STM32F2 and STM32F1 reference manuals.

I’ve asked the appropriate team to fix this in the coming releases.

Please mark this answer as "Best Answer" by clicking on the "Select as Best" button, this can be very helpful for Community users to find this post more quickly.

Thanks for your contribution.

Imen