STM32CubeF4/Projects/STM32F412ZG-Nucleo/Examples/WWDG/WWDG_Example/Src/main.c

/**
  ******************************************************************************
  * @file    WWDG/WWDG_Example/Src/main.c
  * @author  MCD Application Team
  * @brief   This sample code shows how to use the STM32F412xG WWDG HAL API
  *          to update at regular period the WWDG counter and how to simulate
  *          a software fault generating an MCU WWDG reset on expiry of a
  *          programmed time period.
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2017 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */

/* Includes ------------------------------------------------------------------*/
#include "main.h"

/** @addtogroup STM32F4xx_HAL_Examples
  * @{
  */

/** @addtogroup WWDG_Example
  * @{
  */

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* WWDG handler declaration */
static WWDG_HandleTypeDef   WwdgHandle;

/* Private function prototypes -----------------------------------------------*/
static void SystemClock_Config(void);
static void Error_Handler(void);

/* Private functions ---------------------------------------------------------*/

/**
  * @brief  Main program
  * @param  None
  * @retval None
  */
int main(void)
{
  /* STM32F4xx 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 to 100 MHz */
  SystemClock_Config();

  /* Configure LED1, LED2, LED3 */
  BSP_LED_Init(LED1);
  BSP_LED_Init(LED2);
  BSP_LED_Init(LED3);

  /* Configure User push-button */
  BSP_PB_Init(BUTTON_USER, BUTTON_MODE_EXTI);
  /*##-1- Check if the system has resumed from WWDG reset ####################*/
  if (__HAL_RCC_GET_FLAG(RCC_FLAG_WWDGRST) != RESET)
  {
    /* WWDGRST flag set: Turn LED1 on */
    BSP_LED_On(LED1);

    /* Clear reset flags */
    __HAL_RCC_CLEAR_RESET_FLAGS();
  }
  else
  {
    /* WWDGRST flag is not set: Turn LED1 off */
    BSP_LED_Off(LED1);
  }

  /*##-2- Configure the WWDG peripheral ######################################*/
  /* WWDG clock counter = (PCLK1 (50MHz)/4096)/8) = 1525 Hz (~655 us) 
     WWDG Window value = 80 means that the WWDG counter should be refreshed only 
     when the counter is below 80 (and greater than 64/0x40) otherwise a reset will 
     be generated. 
     WWDG Counter value = 127, WWDG timeout = ~655 us * 64 = 42 ms */
  WwdgHandle.Instance = WWDG;

  WwdgHandle.Init.Prescaler = WWDG_PRESCALER_8;
  WwdgHandle.Init.Window    = 80;
  WwdgHandle.Init.Counter   = 127;

  if (HAL_WWDG_Init(&WwdgHandle) != HAL_OK)
  {
    /* Initialization Error */
    Error_Handler();
  }

  /* Infinite loop */
  while (1)
  {
    /* Toggle LED3 */
    BSP_LED_Toggle(LED3);

    /* Insert 37 ms delay */
    HAL_Delay(37);

    /* Refresh WWDG: update counter value to 127, the refresh window is:
 between 31 ms (~655 * (127-80)) and 42 ms (~655 * 64) */

    if (HAL_WWDG_Refresh(&WwdgHandle) != HAL_OK)
    {
      Error_Handler();
    }
  }
}

/**
  * @brief  System Clock Configuration
  *         The system Clock is configured as follow : 
  *            System Clock source            = PLL (HSE)
  *            SYSCLK(Hz)                     = 100000000
  *            HCLK(Hz)                       = 100000000
  *            AHB Prescaler                  = 1
  *            APB1 Prescaler                 = 2
  *            APB2 Prescaler                 = 1
  *            HSE Frequency(Hz)              = 8000000
  *            PLL_M                          = 8
  *            PLL_N                          = 200
  *            PLL_P                          = 2
  *            PLL_Q                          = 7
  *            PLL_R                          = 2
  *            VDD(V)                         = 3.3
  *            Main regulator output voltage  = Scale1 mode
  *            Flash Latency(WS)              = 3
  * @param  None
  * @retval None
  */
static void SystemClock_Config(void)
{
  RCC_ClkInitTypeDef RCC_ClkInitStruct;
  RCC_OscInitTypeDef RCC_OscInitStruct;
  HAL_StatusTypeDef ret = HAL_OK;

  /* 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.  */
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

  /* Enable HSE Oscillator and activate PLL with HSE as source */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_BYPASS;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLM = 8;
  RCC_OscInitStruct.PLL.PLLN = 200;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  RCC_OscInitStruct.PLL.PLLQ = 7;
  RCC_OscInitStruct.PLL.PLLR = 2;
  ret = HAL_RCC_OscConfig(&RCC_OscInitStruct);
  
  if(ret != HAL_OK)
  {
    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_DIV2;  
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;  
  ret = HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_3);
  if(ret != HAL_OK)
  {
    while(1) { ; }  
  }
}

/**
  * @brief  This function is executed in case of error occurrence.
  * @param  None
  * @retval None
  */
static void Error_Handler(void)
{
  /* Turn LED2 on */
  BSP_LED_On(LED2);
  while(1)
  {
  }
}

#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

/**
  * @}
  */

/**
  * @}
  */