STM32 standby wake-up BUG?

[one V]

STM32 standby mode, standby wake-up pin PA0 and RTC wake up, both can work normally. The problem encountered is: If the wake-up pin PA0 is kept high, when the PA0 high-level hold time exceeds the wake-up time set by the RTC after standby, the chip dies unless the reset button is pressed. Temporarily only test the standby wake-up of the two types of STM32F0 and STM32F4, HAL library.

[waclawek.jan]

Post code and describe, what do you exactly mean by "completely stuck".

JW

[one V]

There is no problem with the separate button (PA0) standby wake-up and RTC standby wake-up. However, if the button (PA0) is pressed and the wake-up pin is held high, the entire MCU will be completely stuck when the RTC time arrives to wake up standby. A reset pin is required to reset.

[GEmel]

We have faced with the same problem in our devices. We are using STM32F405RGT6 and SPL library. There is no problem to wake-up using PA0 or RTC separately. But if the wake-up pin (PA0) is held high (in our case it may happen if connected button gets stuck), MCU can not wake-up using RTC. Only reset pin allows to restore normal work.

[waclawek.jan]

Sounds like erratum Wakeup sequence from Standby mode when using more than

one wakeup source ...

JW

[DGolo]

I found same problem on a STM32F207VG. Separately PA0 wakeup and tamper/timestamp(PC13) wakeup from standby mode work fine.

But if I enable it both, then PA0 wakeup work fine, but PC13 tamper activation makes MCU freeze. It does not work until a hardware reset is made.

[DGolo]

And a problem solved.

If PA0 = 1, when MCU goes to standby, RTC interrupt does freeze MCU.

But if PA0=0(when a MCU goes to standby), and PA0 rising - wakeup work. And a RTC wakeup work too!

In my schematic wakeup button was connected from PA0 to ground, and PA0 line has pull-up to +3V.

I thinked a MCU will be wakeup from standby on release button(rising edge). Now i change schematic - PA0 will be pull-up to GND, and button switch it to +3V.