stm32f4 __wfi

[Christian Mauderer]

On 20/06/2019 13:25, Jython wrote:
> do have service routine,  handler can printk log,  SLEEPONEXIT is 0

So your handler is called? But it seems that the processor wakes up
then. How does the "won't stop sleep mode" look like?

> 
> On Thu, Jun 20, 2019 at 5:19 PM Christian Mauderer <list at c-mauderer.de
> <mailto:list at c-mauderer.de>> wrote:
> 
>     On 20/06/2019 10:57, Jython wrote:
>     > a GPIO EXTI line,
>     > rtems idle phrase called __wfi, does it make stm32 enter standby mode?
>     > so key can not wake up it from sleep function
> 
>     Please take a look at the reference manual of your chip. Most likely
>     it's "RM0090 Rev 18" but make sure that's the right part number:
> 
>         https://www.st.com/resource/en/reference_manual/dm00031020.pdf
> 
>     On page 127 there is a description of "Entering low-power mode":
> 
>         "Low-power modes are entered by the MCU by executing the WFI (Wait
>         For Interrupt), or WFE (Wait for Event) instructions, or when the
>         SLEEPONEXIT bit in the Cortex ®-M4 with FPU System Control
>         register is set on Return from ISR."
> 
>     There is also a description for "Exiting low-power mode". For WFI "any
>     peripheral interrupt acknowledged by the NVIC can wake up the device."
>     So your interrupt has to be set up.
> 
>     Your code seems to enable the interrupt. But have you registered a
>     interrupt service routine? Otherwise you might get problems with an
>     unhandled interrupt on wakeup.
> 
>     I only skimmed through the power controller chapter. But it seems that
>     if you have SLEEPDEEP bit set, you will enter a deeper sleep mode
>     where peripheral clocks can be disabled. In that state it's possible
>     that only special pins (like the WKUP) can wake up the processor
>     again. Please have a detailed look at that chapter to find out all
>     traps.
> 
>     Best regards
> 
>     Christian
> 
>     >
>     >
>     >     void keys_init()
>     >     {
>     >         // config gpio
>     >     stm32f4_gpio_set_config(&io_key1);  // PA12
>     >     stm32f4_gpio_set_config(&io_key2);
>     >         stm32f4_gpio_set_config(&io_key3);
>     >     stm32f4_gpio_set_config(&io_key4);
>     >
>     >       
>     >         //  SYSCFGEN and exit map
>     >     (*(uint32_t*)0x40023844) |= 1<<14;
>     >       
>     >         SYSCFG_EXTICR3 = 0;
>     >         SYSCFG_EXTICR4 = 0;
>     >       
>     >
>     >
>     >         // EXIT INIT
>     >     EXTI_IMR |= (1<<12);
>     >     EXTI_RTSR |= (1<<12);
>     >
>     >         EXTI_IMR |= (1<<11);
>     >     EXTI_RTSR |= (1<<11);
>     >
>     >         EXTI_IMR |= (1<<10);
>     >     EXTI_RTSR |= (1<<10);
>     >
>     >         EXTI_IMR |= (1<<9);
>     >     EXTI_RTSR |= (1<<9);
>     >
>     >
>     >         //NVIC_Init
>     >         //NVIC it group2
>     >
>     >     SCB_AIRCR = 0x05FA0000 | 0x500;
>     >     // ip Interrupt priority register x
>     >
>     >     //(*(volatile uint8_t*)0xE000E417) = 0xe0;  //23
>     >         //(*(volatile uint8_t*)0xE000E428) = 0xe0;  // 40
>     >         (*(volatile uint8_t*)0xE000E417) = 0x50;  //23
>     >         (*(volatile uint8_t*)0xE000E428) = 0x50;  // 40
>     >
>     >
>     >
>     >     // 23 40 Interrupt set-enable register x (NVIC_ISERx)
>     >         // nvic enable interrupter number
>     >         // 0xE000E100
>     >         (*(volatile uint32_t*)0xE000E100) |= (1<<23);
>     >         (*(volatile uint32_t *)0xE000E104) |= (1<< (40%32));
>     >     }
>     >
>     >
>     > On Thu, Jun 20, 2019 at 4:05 PM Christian Mauderer
>     <list at c-mauderer.de <mailto:list at c-mauderer.de>
>     > <mailto:list at c-mauderer.de <mailto:list at c-mauderer.de>>> wrote:
>     >
>     >     On 20/06/2019 05:28, Jython wrote:
>     >     > hi, it seems that exit key interrupt won't stop sleep mode, why?
>     >     >
>     >     > [...]
>     >     >
>     >
>     >     What do you mean by "exit key interrupt"? I don't know the
>     STM32F4 that
>     >     well. So please give some more details.
>     >
>     >     I would expect that either only specific interrupt sources can
>     wake up
>     >     the processor from a deep sleep mode or that you can configure
>     which
>     >     peripherals are still active. If your "exit key" is a GPIO
>     line with
>     >     interrupt capability you should have a look at whether the
>     module is
>     >     still active.
>     >
>     >     Best regards
>     >
>     >     Christian
>     >
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