stm32f2xx_pwr.c

STM32+Grlib

@endverbatim
  * @{
  */

/**
  * @brief  Enables or disables the Flash Power Down in STOP mode.
  * @param  NewState: new state of the Flash power mode.
  *          This parameter can be: ENABLE or DISABLE.
  * @retval None
  */
void PWR_FlashPowerDownCmd(FunctionalState NewState)
{
  /* Check the parameters */
  assert_param(IS_FUNCTIONAL_STATE(NewState));

  *(__IO uint32_t *) CR_FPDS_BB = (uint32_t)NewState;
}

/**
  * @}
  */

/** @defgroup PWR_Group6 Low Power modes configuration functions
 *  @brief   Low Power modes configuration functions 
 *
@verbatim   
 ===============================================================================
                    Low Power modes configuration functions
 ===============================================================================  

  The devices feature 3 low-power modes:
   - Sleep mode: Cortex-M3 core stopped, peripherals kept running.
   - Stop mode: all clocks are stopped, regulator running, regulator in low power mode
   - Standby mode: 1.2V domain powered off.
   
   Sleep mode
   ===========
    - Entry:
      - The Sleep mode is entered by using the __WFI() or __WFE() functions.
    - Exit:
      - Any peripheral interrupt acknowledged by the nested vectored interrupt 
        controller (NVIC) can wake up the device from Sleep mode.

   Stop mode
   ==========
   In Stop mode, all clocks in the 1.2V domain are stopped, the PLL, the HSI,
   and the HSE RC oscillators are disabled. Internal SRAM and register contents 
   are preserved.
   The voltage regulator can be configured either in normal or low-power mode.
   To minimize the consumption In Stop mode, FLASH can be powered off before 
   entering the Stop mode. It can be switched on again by software after exiting 
   the Stop mode using the PWR_FlashPowerDownCmd() function. 
   
    - Entry:
      - The Stop mode is entered using the PWR_EnterSTOPMode(PWR_Regulator_LowPower,) 
        function with regulator in LowPower or with Regulator ON.
    - Exit:
      - Any EXTI Line (Internal or External) configured in Interrupt/Event mode.
      
   Standby mode
   ============
   The Standby mode allows to achieve the lowest power consumption. It is based 
   on the Cortex-M3 deepsleep mode, with the voltage regulator disabled. 
   The 1.2V domain is consequently powered off. The PLL, the HSI oscillator and 
   the HSE oscillator are also switched off. SRAM and register contents are lost 
   except for the RTC registers, RTC backup registers, backup SRAM and Standby 
   circuitry.
   
   The voltage regulator is OFF.
      
    - Entry:
      - The Standby mode is entered using the PWR_EnterSTANDBYMode() function.
    - Exit:
      - WKUP pin rising edge, RTC alarm (Alarm A and Alarm B), RTC wakeup,
        tamper event, time-stamp event, external reset in NRST pin, IWDG reset.              

   Auto-wakeup (AWU) from low-power mode
   =====================================
   The MCU can be woken up from low-power mode by an RTC Alarm event, an RTC 
   Wakeup event, a tamper event, a time-stamp event, or a comparator event, 
   without depending on an external interrupt (Auto-wakeup mode).

   - RTC auto-wakeup (AWU) from the Stop mode
     ----------------------------------------
     
     - To wake up from the Stop mode with an RTC alarm event, it is necessary to:
       - Configure the EXTI Line 17 to be sensitive to rising edges (Interrupt 
         or Event modes) using the EXTI_Init() function.
       - Enable the RTC Alarm Interrupt using the RTC_ITConfig() function
       - Configure the RTC to generate the RTC alarm using the RTC_SetAlarm() 
         and RTC_AlarmCmd() functions.
     - To wake up from the Stop mode with an RTC Tamper or time stamp event, it 
       is necessary to:
       - Configure the EXTI Line 21 to be sensitive to rising edges (Interrupt 
         or Event modes) using the EXTI_Init() function.
       - Enable the RTC Tamper or time stamp Interrupt using the RTC_ITConfig() 
         function
       - Configure the RTC to detect the tamper or time stamp event using the
         RTC_TimeStampConfig(), RTC_TamperTriggerConfig() and RTC_TamperCmd()
         functions.
     - To wake up from the Stop mode with an RTC WakeUp event, it is necessary to:
       - Configure the EXTI Line 22 to be sensitive to rising edges (Interrupt 
         or Event modes) using the EXTI_Init() function.
       - Enable the RTC WakeUp Interrupt using the RTC_ITConfig() function
       - Configure the RTC to generate the RTC WakeUp event using the RTC_WakeUpClockConfig(), 
         RTC_SetWakeUpCounter() and RTC_WakeUpCmd() functions.

   - RTC auto-wakeup (AWU) from the Standby mode
     -------------------------------------------
     - To wake up from the Standby mode with an RTC alarm event, it is necessary to:
       - Enable the RTC Alarm Interrupt using the RTC_ITConfig() function
       - Configure the RTC to generate the RTC alarm using the RTC_SetAlarm() 
         and RTC_AlarmCmd() functions.
     - To wake up from the Standby mode with an RTC Tamper or time stamp event, it 
       is necessary to:
       - Enable the RTC Tamper or time stamp Interrupt using the RTC_ITConfig() 
         function
       - Configure the RTC to detect the tamper or time stamp event using the
         RTC_TimeStampConfig(), RTC_TamperTriggerConfig() and RTC_TamperCmd()
         functions.
     - To wake up from the Standby mode with an RTC WakeUp event, it is necessary to:
       - Enable the RTC WakeUp Interrupt using the RTC_ITConfig() function
       - Configure the RTC to generate the RTC WakeUp event using the RTC_WakeUpClockConfig(), 
         RTC_SetWakeUpCounter() and RTC_WakeUpCmd() functions.

@endverbatim
  * @{
  */

/**
  * @brief  Enters STOP mode.
  *   
  * @note   In Stop mode, all I/O pins keep the same state as in Run mode.
  * @note   When exiting Stop mode by issuing an interrupt or a wakeup event, 
  *         the HSI RC oscillator is selected as system clock.
  * @note   When the voltage regulator operates in low power mode, an additional 
  *         startup delay is incurred when waking up from Stop mode. 
  *         By keeping the internal regulator ON during Stop mode, the consumption 
  *         is higher although the startup time is reduced.           
  *     
  * @param  PWR_Regulator: specifies the regulator state in STOP mode.
  *          This parameter can be one of the following values:
  *            @arg PWR_Regulator_ON: STOP mode with regulator ON
  *            @arg PWR_Regulator_LowPower: STOP mode with regulator in low power mode
  * @param  PWR_STOPEntry: specifies if STOP mode in entered with WFI or WFE instruction.
  *          This parameter can be one of the following values:
  *            @arg PWR_STOPEntry_WFI: enter STOP mode with WFI instruction
  *            @arg PWR_STOPEntry_WFE: enter STOP mode with WFE instruction
  * @retval None
  */
void PWR_EnterSTOPMode(uint32_t PWR_Regulator, uint8_t PWR_STOPEntry)
{
  uint32_t tmpreg = 0;
  
  /* Check the parameters */
  assert_param(IS_PWR_REGULATOR(PWR_Regulator));
  assert_param(IS_PWR_STOP_ENTRY(PWR_STOPEntry));
  
  /* Select the regulator state in STOP mode ---------------------------------*/
  tmpreg = PWR->CR;
  /* Clear PDDS and LPDSR bits */
  tmpreg &= CR_DS_MASK;
  
  /* Set LPDSR bit according to PWR_Regulator value */
  tmpreg |= PWR_Regulator;
  
  /* Store the new value */
  PWR->CR = tmpreg;
  
  /* Set SLEEPDEEP bit of Cortex System Control Register */
  SCB->SCR |= SCB_SCR_SLEEPDEEP_Msk;
  
  /* Select STOP mode entry --------------------------------------------------*/
  if(PWR_STOPEntry == PWR_STOPEntry_WFI)
  {   
    /* Request Wait For Interrupt */
    __WFI();
  }
  else
  {
    /* Request Wait For Event */
    __WFE();
  }
  /* Reset SLEEPDEEP bit of Cortex System Control Register */
  SCB->SCR &= (uint32_t)~((uint32_t)SCB_SCR_SLEEPDEEP_Msk);  
}

/**
  * @brief  Enters STANDBY mode.
  * @note   In Standby mode, all I/O pins are high impedance except for:
  *          - Reset pad (still available) 
  *          - RTC_AF1 pin (PC13) if configured for tamper, time-stamp, RTC 
  *            Alarm out, or RTC clock calibration out.
  *          - RTC_AF2 pin (PI8) if configured for tamper or time-stamp.  
  *          - WKUP pin 1 (PA0) if enabled.       
  * @param  None
  * @retval None
  */
void PWR_EnterSTANDBYMode(void)
{
  /* Clear Wakeup flag */
  PWR->CR |= PWR_CR_CWUF;
  
  /* Select STANDBY mode */
  PWR->CR |= PWR_CR_PDDS;
  
  /* Set SLEEPDEEP bit of Cortex System Control Register */
  SCB->SCR |= SCB_SCR_SLEEPDEEP_Msk;
  
/* This option is used to ensure that store operations are completed */
#if defined ( __CC_ARM   )
  __force_stores();
#endif
  /* Request Wait For Interrupt */
  __WFI();
}

/**
  * @}
  */

/** @defgroup PWR_Group7 Flags management functions
 *  @brief   Flags management functions 
 *
@verbatim   
 ===============================================================================
                           Flags management functions
 ===============================================================================  

@endverbatim
  * @{
  */

/**
  * @brief  Checks whether the specified PWR flag is set or not.
  * @param  PWR_FLAG: specifies the flag to check.
  *          This parameter can be one of the following values:
  *            @arg PWR_FLAG_WU: Wake Up flag. This flag indicates that a wakeup event 
  *                  was received from the WKUP pin or from the RTC alarm (Alarm A 
  *                  or Alarm B), RTC Tamper event, RTC TimeStamp event or RTC Wakeup.
  *                  An additional wakeup event is detected if the WKUP pin is enabled 
  *                  (by setting the EWUP bit) when the WKUP pin level is already high.  
  *            @arg PWR_FLAG_SB: StandBy flag. This flag indicates that the system was
  *                  resumed from StandBy mode.    
  *            @arg PWR_FLAG_PVDO: PVD Output. This flag is valid only if PVD is enabled 
  *                  by the PWR_PVDCmd() function. The PVD is stopped by Standby mode 
  *                  For this reason, this bit is equal to 0 after Standby or reset
  *                  until the PVDE bit is set.
  *            @arg PWR_FLAG_BRR: Backup regulator ready flag. This bit is not reset 
  *                  when the device wakes up from Standby mode or by a system reset 
  *                  or power reset.  
  * @retval The new state of PWR_FLAG (SET or RESET).
  */
FlagStatus PWR_GetFlagStatus(uint32_t PWR_FLAG)
{
  FlagStatus bitstatus = RESET;
  
  /* Check the parameters */
  assert_param(IS_PWR_GET_FLAG(PWR_FLAG));
  
  if ((PWR->CSR & PWR_FLAG) != (uint32_t)RESET)
  {
    bitstatus = SET;
  }
  else
  {
    bitstatus = RESET;
  }
  /* Return the flag status */
  return bitstatus;
}

/**
  * @brief  Clears the PWR's pending flags.
  * @param  PWR_FLAG: specifies the flag to clear.
  *          This parameter can be one of the following values:
  *            @arg PWR_FLAG_WU: Wake Up flag
  *            @arg PWR_FLAG_SB: StandBy flag
  * @retval None
  */
void PWR_ClearFlag(uint32_t PWR_FLAG)
{
  /* Check the parameters */
  assert_param(IS_PWR_CLEAR_FLAG(PWR_FLAG));
         
  PWR->CR |=  PWR_FLAG << 2;
}

/**
  * @}
  */

/**
  * @}
  */

/**
  * @}
  */

/**
  * @}
  */

/******************* (C) COPYRIGHT 2011 STMicroelectronics *****END OF FILE****/