Does the IWDG window value cause a reset if the watchdog is refreshed too often on STM32G473?

[JohnFrancis]

I’m working with an STM32G473QETx.

Does the IWDG window value cause the MCU to reset if the watchdog is refreshed too often (i.e., refreshed too early)?

if I set the IWDG window value to something smaller (e.g., 1600), will the MCU reset if I refresh the watchdog more frequently than expected?

Any clarification on how the IWDG window works on the STM32G4 series would be appreciated.

[TDK]

No, the IWDG doesn’t have a window, just refresh it before it hits 0 and it won’t reset. Reset it as often as you like.

[waclawek.jan · Accepted solution]

@TDK,

the newer STM32 - including 'G4 - have window option in the IWDG. And then if IWDG_WINR is set to a value lower than IWDG_RLR, it can cause reset if the watchdog is refreshed too soon after previous refresh.

JW

[JohnFrancis]

Thank you for your reply. Suppose I don’t need to use the IWDG window option — what value should I set? I configured the IWDG timeout to 1.5 seconds by using a prescaler of 32 and a reload value of 1600 based on my clock frequency. The IWDG window value must be between 0 and 4095. Which value should I set to effectively disable the window option?

[TDK]

Thanks for the correction Jan, always learning. So they turned the IWDG into a WWDG but didn’t change the name. Odd choice. Suppose the clock is still independent so maybe it should be called IWWDG.