text: /**
    ******************************************************************************
    * @file    PWR/PWR_SLEEP/Src/main.c
    * @author  MCD Application Team
    * @brief   This sample code shows how to use STM32L4xx PWR HAL API to enter
    *          and exit the Sleep mode.
    ******************************************************************************
    * @attention
    *
    * <h2><center>&copy; COPYRIGHT(c) 2017 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 STM32L4xx_HAL_Examples
    * @{
    */
  
  /** @addtogroup PWR_SLEEP
    * @{
    */
  
  /* Private typedef -----------------------------------------------------------*/
  /* Private define ------------------------------------------------------------*/
  #define LED_TOGGLE_DELAY         100
  /* Private macro -------------------------------------------------------------*/
  /* Private variables ---------------------------------------------------------*/
  static __IO uint32_t TimingDelay;
  /* Private function prototypes -----------------------------------------------*/
  void SystemClock_Config(void);
  static void SystemPower_Config(void);
  
  /* Private functions ---------------------------------------------------------*/
  
  /**
    * @brief  Main program
    * @param  None
    * @retval None
    */
  int main(void)
  {
  
    /* STM32L4xx HAL library initialization:
         - Configure the Flash prefetch
         - 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.
         - Set NVIC Group Priority to 4
         - Low Level Initialization
       */
    HAL_Init();
  
    /* Configure the system clock */
    SystemClock_Config();
  
    /* Configure LED2 */
    BSP_LED_Init(LED2);
  
    /* Disable Prefetch Buffer */
    __HAL_FLASH_PREFETCH_BUFFER_DISABLE();
  
    /* Reset all RCC Sleep and Stop modes register to */
    /* improve power consumption                      */
    RCC->AHB1SMENR  = 0x0; 
    RCC->AHB2SMENR  = 0x0;
    RCC->AHB3SMENR  = 0x0;
    
    RCC->APB1SMENR1 = 0x0;
    RCC->APB1SMENR2 = 0x0; 
    RCC->APB2SMENR  = 0x0; 
  
    while (1)
    {
      /* Insert 5 seconds delay */
      HAL_Delay(5000);
      
      /* Configure the system Power */
      SystemPower_Config();
  
      /* User push-button (lines 10 to 15) will be used to wakeup the system from SLEEP mode */
      BSP_PB_Init(BUTTON_USER, BUTTON_MODE_EXTI);
  
      /*Suspend Tick increment to prevent wakeup by Systick interrupt. 
      Otherwise the Systick interrupt will wake up the device within 1ms (HAL time base)*/
      HAL_SuspendTick();
  
      /* Enter Sleep Mode , wake up is done once User push-button is pressed */
      HAL_PWR_EnterSLEEPMode(PWR_MAINREGULATOR_ON, PWR_SLEEPENTRY_WFI);
  
      /* Resume Tick interrupt if disabled prior to SLEEP mode entry */
      HAL_ResumeTick();
      
      /* Re-configure LED2 */
      BSP_LED_Init(LED2);
    }
  }
  
  /**
    * @brief  System Clock Configuration
    *         The system Clock is configured as follows :
    *            System Clock source            = PLL (MSI)
    *            SYSCLK(Hz)                     = 80000000
    *            HCLK(Hz)                       = 80000000
    *            AHB Prescaler                  = 1
    *            APB1 Prescaler                 = 1
    *            APB2 Prescaler                 = 1
    *            MSI Frequency(Hz)              = 4000000
    *            PLL_M                          = 1
    *            PLL_N                          = 40
    *            PLL_R                          = 2
    *            PLL_P                          = 7
    *            PLL_Q                          = 4
    *            Flash Latency(WS)              = 4
    * @param  None
    * @retval None
    */
  void SystemClock_Config(void)
  {
    RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
    RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  
    /* MSI is enabled after System reset, activate PLL with MSI as source */
    RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_MSI;
    RCC_OscInitStruct.MSIState = RCC_MSI_ON;
    RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_6;
    RCC_OscInitStruct.MSICalibrationValue = RCC_MSICALIBRATION_DEFAULT;
    RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
    RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_MSI;
    RCC_OscInitStruct.PLL.PLLM = 1;
    RCC_OscInitStruct.PLL.PLLN = 40;
    RCC_OscInitStruct.PLL.PLLR = 2;
    RCC_OscInitStruct.PLL.PLLP = 7;
    RCC_OscInitStruct.PLL.PLLQ = 4;
    if(HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
    {
      /* Initialization Error */
      while(1);
    }
    
    /* Select PLL 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_PLLCLK;
    RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
    RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;  
    RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;  
    if(HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4) != HAL_OK)
    {
      /* Initialization Error */
      while(1);
    }
  }
  
  /**
    * @brief  System Power Configuration
    * @retval None
    */
  static void SystemPower_Config(void)
  {
    GPIO_InitTypeDef GPIO_InitStructure;
  
        /* Set all GPIO in analog state to reduce power consumption */
      __HAL_RCC_GPIOA_CLK_ENABLE();
      __HAL_RCC_GPIOB_CLK_ENABLE();
      __HAL_RCC_GPIOC_CLK_ENABLE();
      __HAL_RCC_GPIOD_CLK_ENABLE();
      __HAL_RCC_GPIOE_CLK_ENABLE();
      __HAL_RCC_GPIOF_CLK_ENABLE();
      __HAL_RCC_GPIOG_CLK_ENABLE();
      __HAL_RCC_GPIOH_CLK_ENABLE();   
  
      GPIO_InitStructure.Mode = GPIO_MODE_ANALOG;
      GPIO_InitStructure.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
      GPIO_InitStructure.Pull = GPIO_NOPULL;
      GPIO_InitStructure.Pin = GPIO_PIN_All;
  
      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(GPIOE, &GPIO_InitStructure);
      HAL_GPIO_Init(GPIOF, &GPIO_InitStructure);
      HAL_GPIO_Init(GPIOG, &GPIO_InitStructure);
      HAL_GPIO_Init(GPIOH, &GPIO_InitStructure);  
  
      __HAL_RCC_GPIOA_CLK_DISABLE();
      __HAL_RCC_GPIOB_CLK_DISABLE();
      __HAL_RCC_GPIOC_CLK_DISABLE();
      __HAL_RCC_GPIOD_CLK_DISABLE();
      __HAL_RCC_GPIOE_CLK_DISABLE();
      __HAL_RCC_GPIOF_CLK_DISABLE();
      __HAL_RCC_GPIOG_CLK_DISABLE();
      __HAL_RCC_GPIOH_CLK_DISABLE();
  
    /* Enable PWR clock */
    __HAL_RCC_PWR_CLK_ENABLE(); 
  }
  
  /**
    * @brief SYSTICK callback
    * @param None
    * @retval None
    */
  void HAL_SYSTICK_Callback(void)
  {
    HAL_IncTick();
    if (TimingDelay != 0)
    {
      TimingDelay--;
    }
    else
    {
      /* Toggle LED2 */
      BSP_LED_Toggle(LED2);
      TimingDelay = LED_TOGGLE_DELAY;
    }
  }
  
  #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(char *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****/
  