STM32U535NEY6Q: STOP Mode

[Ed_]

For going to sleep with STM32U535NEY6Q with the following example:

``` c

int main(void) {

    HAL_Init();

    SystemClock_Config();

    MX_GPIO_Init();

    // ^ // Configure GPIO pin : INT_BUTTON_Pin

    // | GPIO_InitStruct.Pin = INT_BUTTON_Pin;

    // | GPIO_InitStruct.Mode = GPIO_MODE_IT_RISING_FALLING;

    // | GPIO_InitStruct.Pull = GPIO_NOPULL;

    // | HAL_GPIO_Init(INT_BUTTON_GPIO_Port, &GPIO_InitStruct);

    while(1) {

    DEBUG_PRINTF("%d SLEEP\n", HAL_GetTick());

    HAL_Delay(100);

        HAL_PWREx_EnableUltraLowPowerMode();

        __HAL_PWR_CLEAR_FLAG(PWR_FLAG_STOPF);

        __HAL_RCC_PWR_CLK_ENABLE();

        HAL_PWREx_EnterSTOP2Mode(PWR_STOPENTRY_WFI);

        DEBUG_PRINTF("%d WOKEUP %x\n", HAL_GetTick(), HAL_GPIO_ReadPin(INT_BUTTON_GPIO_Port, INT_BUTTON_Pin));

        HAL_Delay(200);

    }

}

```

Causes it to not go to sleep as such:

```

4045 SLEEP

4148 WOKEUP 0

4351 SLEEP

4453 WOKEUP 0

4656 SLEEP

4758 WOKEUP 0

```

Current knowledge base is I'm treating it as if it were STM32L071KZU3. Reasonable assumption is that there's some PWR/RCC step I'm missing or not clearing, so inquiring on what obvious mistake is being made. Only one EXTI pin set.

[Sarra.S]

Hello @Ed_, 

I would suspect there are other wake-up sources 

add  HAL_SuspendTick(); before entering sleep or stop2 mode and resume the tick interrupt after