text: /**
    ******************************************************************************
    * @file    PWR/PWR_LPRUN/Src/main.c
    * @author  MCD Application Team
    * @brief   This example shows how to use STM32L0xx PWR HAL API to enter the
    *          system to Low Power Run mode and exit from this mode using User push-button.
    ******************************************************************************
    * @attention
    *
    * <h2><center>&copy; COPYRIGHT(c) 2016 STMicroelectronics</center></h2>
    *
    * Redistribution and use in source and binary forms, with or without modification,
    * are permitted provided that the following conditions are met:
    *   1. Redistributions of source code must retain the above copyright notice,
    *      this list of conditions and the following disclaimer.
    *   2. Redistributions in binary form must reproduce the above copyright notice,
    *      this list of conditions and the following disclaimer in the documentation
    *      and/or other materials provided with the distribution.
    *   3. Neither the name of STMicroelectronics nor the names of its contributors
    *      may be used to endorse or promote products derived from this software
    *      without specific prior written permission.
    *
    * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
    * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
    * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
    * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
    * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
    * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
    * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
    * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    *
    ******************************************************************************
    */
  
  /* Includes ------------------------------------------------------------------*/
  #include "main.h"
  
  /** @addtogroup STM32L0xx_HAL_Examples
    * @{
    */
  
  /** @addtogroup PWR_LPRUN
    * @{
    */
  
  /* Private typedef -----------------------------------------------------------*/
  /* Private define ------------------------------------------------------------*/
  /* Private macro -------------------------------------------------------------*/
  /* Private variables ---------------------------------------------------------*/
  /* Private function prototypes -----------------------------------------------*/
  void SystemClock_Config(void);
  static void SystemPower_Config(void);
  
  /* Private functions ---------------------------------------------------------*/
  
  /**
    * @brief  Main program
    * @param  None
    * @retval None
    */
  int main(void)
  {
    /* STM32L0xx HAL library initialization:
         - Configure the Flash prefetch, Flash preread and Buffer caches
         - Systick timer is configured by default as source of time base, but user 
               can eventually implement his proper time base source (a general purpose 
               timer for example or other time source), keeping in mind that Time base 
               duration should be kept 1ms since PPP_TIMEOUT_VALUEs are defined and 
               handled in milliseconds basis.
         - Low Level Initialization
       */
    HAL_Init();
  
    /* Configure the system clock @ 32 KHz */
    SystemClock_Config();
  
    /* Configure LED2 */
    BSP_LED_Init(LED2);
  
    /* Disable Prefetch Buffer */
    __HAL_FLASH_PREFETCH_BUFFER_DISABLE();
  
    /* Configure the system Power */
    SystemPower_Config();
  
    while (1)
    {
      /*  Configure User push-button*/
      BSP_PB_Init(BUTTON_KEY,BUTTON_MODE_GPIO);
  
      /* Wait Until User push-button pressed */
      while(BSP_PB_GetState(BUTTON_KEY) != GPIO_PIN_RESET)
      {
      }
  
      /* Wait Until User push-button released */
      while(BSP_PB_GetState(BUTTON_KEY) != GPIO_PIN_SET)
      {
      }
  
      /* Enter LP RUN mode */
      HAL_PWREx_EnableLowPowerRunMode();
  
      /* Wait until the system enters LP RUN and the Regulator is in LP mode */
      while(__HAL_PWR_GET_FLAG(PWR_FLAG_REGLP) == RESET)
      {
      }
  
      /* Wait Until User push-button pressed */
      while(BSP_PB_GetState(BUTTON_KEY) != GPIO_PIN_RESET)
      {
      }
  
      /* Wait Until User push-button released */
      while(BSP_PB_GetState(BUTTON_KEY) != GPIO_PIN_SET)
      {
      }
  
      /* Exit LP RUN mode */
      HAL_PWREx_DisableLowPowerRunMode();
  
      /* Wait until the system exits LP RUN and the Regulator is in main mode */
      while(__HAL_PWR_GET_FLAG(PWR_FLAG_REGLP) != RESET)
      {
      }
    }
  }
  
  /**
    * @brief  System Clock Configuration
    *         The system Clock is configured as follow : 
    *            System Clock source            = (MSI)
    *            MSI Range                      = 2
    *            SYSCLK(Hz)                     = 64000
    *            HCLK(Hz)                       = 32000
    *            AHB Prescaler                  = 2
    *            APB1 Prescaler                 = 1
    *            APB2 Prescaler                 = 1
    *            Main regulator output voltage  = Scale2 mode
    * @param  None
    * @retval None
    */
  void SystemClock_Config(void)
  {
    RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
    RCC_OscInitTypeDef RCC_OscInitStruct = {0};
    /* Enable Power Control clock */
    __HAL_RCC_PWR_CLK_ENABLE();
  
    /* The voltage scaling allows optimizing the power consumption when the device is 
       clocked below the maximum system frequency, to update the voltage scaling value 
       regarding system frequency refer to product datasheet.
       Low power sleep mode can only be entered when VCORE is in range 2. */
    __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE2);
    
    /* Enable MSI Oscillator */
    RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_MSI;
    RCC_OscInitStruct.MSIState = RCC_MSI_ON;
    RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_5;
    RCC_OscInitStruct.MSICalibrationValue = 0x00;
    RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
    if (HAL_RCC_OscConfig(&RCC_OscInitStruct)!= HAL_OK)
    {
      /* Initialization Error */
      while(1); 
    }
    
    /* Select MSI as system clock source and configure the HCLK, PCLK1 and PCLK2 
       clocks dividers */
    RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
    RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_MSI;
    RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV2;
    RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;  
    RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;  
    if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0)!= HAL_OK)
    {
      /* Initialization Error */
      while(1); 
    }
    
    /* Set MSI range to 0 */
    __HAL_RCC_MSI_RANGE_CONFIG(RCC_MSIRANGE_0);
    
    /* Configure the SysTick to have interrupt in 10 ms time basis*/
    HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq()/100);
  }
  
  /**
    * @brief  System Power Configuration
    *         The system Power is configured as follow : 
    *            + System Running at MSI (~32KHz)
    *            + Flash 0 wait state  
    *            + Voltage Range 2
    *            + Code running from Internal FLASH
    *            + Wakeup using User push-button PC.13
    * @param  None
    * @retval None
    */
  static void SystemPower_Config(void)
  {
    GPIO_InitTypeDef GPIO_InitStructure;
  
    /* Enable Power Control clock */
    __HAL_RCC_PWR_CLK_ENABLE();
  
    /* Enable GPIOs clock */
    __HAL_RCC_GPIOA_CLK_ENABLE();
    __HAL_RCC_GPIOB_CLK_ENABLE();
    __HAL_RCC_GPIOC_CLK_ENABLE();
    __HAL_RCC_GPIOD_CLK_ENABLE();
    __HAL_RCC_GPIOH_CLK_ENABLE();
    __HAL_RCC_GPIOE_CLK_ENABLE();
  
    /* Configure all GPIO port pins in Analog Input mode (floating input trigger OFF) */
    /* Note: Debug using ST-Link is not possible during the execution of this   */
    /*       example because communication between ST-link and the device       */
    /*       under test is done through UART. All GPIO pins are disabled (set   */
    /*       to analog input mode) including  UART I/O pins.           */
    GPIO_InitStructure.Pin = GPIO_PIN_All;
    GPIO_InitStructure.Mode = GPIO_MODE_ANALOG;
    GPIO_InitStructure.Pull = GPIO_NOPULL;
  
    HAL_GPIO_Init(GPIOA, &GPIO_InitStructure); 
    HAL_GPIO_Init(GPIOB, &GPIO_InitStructure);
    HAL_GPIO_Init(GPIOC, &GPIO_InitStructure);
    HAL_GPIO_Init(GPIOD, &GPIO_InitStructure);
    HAL_GPIO_Init(GPIOH, &GPIO_InitStructure);
    HAL_GPIO_Init(GPIOE, &GPIO_InitStructure);
  
    /* Disable GPIOs clock */
    __HAL_RCC_GPIOA_CLK_DISABLE();
    __HAL_RCC_GPIOB_CLK_DISABLE();
    __HAL_RCC_GPIOC_CLK_DISABLE();
    __HAL_RCC_GPIOD_CLK_DISABLE();
    __HAL_RCC_GPIOH_CLK_DISABLE();
    __HAL_RCC_GPIOE_CLK_DISABLE();
  }
  
  
  #ifdef  USE_FULL_ASSERT
  
  /**
    * @brief  Reports the name of the source file and the source line number
    *         where the assert_param error has occurred.
    * @param  file: pointer to the source file name
    * @param  line: assert_param error line source number
    * @retval None
    */
  void assert_failed(uint8_t *file, uint32_t line)
  {
    /* User can add his own implementation to report the file name and line number,
       ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
  
    /* Infinite loop */
    while (1)
    {
    }
  }
  #endif
  
  /**
    * @}
    */
  
  /**
    * @}
    */
  
  /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
  