STM32F100RC -- GPIO in standby mode?

What is the state of GPIO pins when microcontroller is in standby mode?  
Each pin remembers it's own state: input, output, analog, pull-up, logic 
level on it?  Which document (datasheet, etc) and where specifies this 
behaviour?

On 31/03/2012 11:10, Kirill Frolov wrote:
>
> What is the state of GPIO pins when microcontroller is in standby mode?
> Each pin remembers it's own state: input, output, analog, pull-up, logic
> level on it?  Which document (datasheet, etc) and where specifies this
> behaviour?
>
>

The pins don't do what you ask !

 From the ST RM0041 Reference manual for the STM32F100

I/O states in Standby mode
In Standby mode, all I/O pins are high impedance except:
● Reset pad (still available)
● TAMPER pin if configured for tamper or calibration out
● WKUP pin, if enabled

You can download it from the ST website.


Michael Kellett

On Sat, 31 Mar 2012 14:04:12 +0100, MK wrote:

>> Each pin remembers it's own state: input, output, analog, pull-up,
>> logic level on it?  Which document (datasheet, etc) and where specifies
>> this behaviour?
> The pins don't do what you ask !

  But they do...

> From the ST RM0041 Reference manual for the STM32F100
> In Standby mode, all I/O pins are high impedance except...

  I am putting microcontroller in standby mode with code listed below. 
LED is turned on before entering standby mode. And then microcontroller 
enters standby mode LED is not turned off (and no flashing -- CPU sleeps).

  And because by default all microcontroller pins configured as digital 
inputs consuming current increases when I move hands close to 
microcontroller.

  What I doing wrong? 

  Code:

        GPIOA->BSRR=GPIO_BSRR_BR8;   // LED is on

        SCB->SCR |= SCB_SCR_SLEEPDEEP;
        PWR->CR |= PWR_CR_PDDS | PWR_CR_CWUF | PWR_CR_LPDS;
        //PWR->CSR &= ~PWR_CSR_WUF;
        for (n=0; n<10; n++) asm volatile ("nop");
        asm volatile ("WFE");

        /* flash LED if WFE instruction has no effect */
        while (1) {
                GPIOA->BSRR=GPIO_BSRR_BS8;
                delay(10000);
                GPIOA->BSRR=GPIO_BSRR_BR8;
                delay(10000);
        }

On Sun, 01 Apr 2012 09:13:19 +0000, Kirill Frolov wrote:

>   I am putting microcontroller in standby mode with code listed below.
> LED is turned on before entering standby mode. And then microcontroller
> enters standby mode LED is not turned off (and no flashing -- CPU
> sleeps).
>   What I doing wrong?

  I forgot to enable clock to power control module...

  RCC->APB1ENR = RCC_APB1ENR_PWREN | RCC_APB1ENR_BKPEN;