STM32CubeF3/Projects/STM32373C_EVAL/Examples/TIM/TIM_DMA/Src/main.c

/**
  ******************************************************************************
  * @file    TIM/TIM_DMA/Src/main.c 
  * @author  MCD Application Team
  * @brief   This sample code shows how to use DMA with TIM15 Update request to
  *          transfer Data from memory to TIM15 Capture Compare Register 1 (CCR1).
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; Copyright (c) 2016 STMicroelectronics.
  * All rights reserved.</center></h2>
  *
  * This software component is licensed by ST under BSD 3-Clause license,
  * the "License"; You may not use this file except in compliance with the
  * License. You may obtain a copy of the License at:
  *                        opensource.org/licenses/BSD-3-Clause
  *
  ******************************************************************************
  */

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

/** @addtogroup STM32F3xx_HAL_Examples
  * @{
  */

/** @addtogroup TIM_DMA
  * @{
  */

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Timer handler declaration */
TIM_HandleTypeDef    TimHandle;

/* Timer Output Compare Configuration Structure declaration */
TIM_OC_InitTypeDef sConfig;

/* Capture Compare buffer */
uint32_t aCCValue_Buffer[3] = {0, 0, 0};

/* Timer Period*/
uint32_t uhTimerPeriod  = 0;

/* 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)
{

  /* STM32F3xx 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 LED3 */
  BSP_LED_Init(LED3);

  /* Configure the system clock to have a system clock = 72 Mhz */
  SystemClock_Config();

  /* Compute the value of ARR regiter to generate signal frequency at 17.57 Khz */
  uhTimerPeriod = (uint32_t) ((SystemCoreClock / 17570 ) - 1);
  /* Compute CCR1 value to generate a duty cycle at 75% */
  aCCValue_Buffer[0] = (uint32_t)(((uint32_t) 75 * (uhTimerPeriod - 1)) / 100);
  /* Compute CCR2 value to generate a duty cycle at 50% */
  aCCValue_Buffer[1] = (uint32_t)(((uint32_t) 50 * (uhTimerPeriod - 1)) / 100);
  /* Compute CCR3 value to generate a duty cycle at 25% */
  aCCValue_Buffer[2] = (uint32_t)(((uint32_t) 25 * (uhTimerPeriod - 1)) / 100);
  
  
  /*##-1- Configure the TIM peripheral #######################################*/ 
  /* --------------------------------------------------------------------------- 
  TIM15 input clock (TIM15CLK) is set to APB2 clock (PCLK2), since APB2 
  prescaler is 1.   
    TIM15CLK = PCLK2  
    PCLK2 = HCLK 
    => TIM15CLK = HCLK = SystemCoreClock
  
  TIM15CLK = SystemCoreClock, Prescaler = 0, TIM15 counter clock = SystemCoreClock
  SystemCoreClock is set to 72 MHz for STM32F3xx devices.
          
  The objective is to configure TIM15 channel 1 to generate complementary PWM
  signal with a frequency equal to 17.57 KHz:
     - TIM15_Period = (SystemCoreClock / 17570) - 1
  and a variable duty cycle that is changed by the DMA after a specific number of
  Update DMA request.
                                              
  The number of this repetitive requests is defined by the TIM15 Repetion counter,
  each 4 Update Requests, the TIM15 Channel 1 Duty Cycle changes to the next new 
  value defined by the aCCValue_Buffer.
                  
  Note: 
     SystemCoreClock variable holds HCLK frequency and is defined in system_stm32f3xx.c file.
     Each time the core clock (HCLK) changes, user had to update SystemCoreClock 
     variable value. Otherwise, any configuration based on this variable will be incorrect.
     This variable is updated in three ways:
      1) by calling CMSIS function SystemCoreClockUpdate()
      2) by calling HAL API function HAL_RCC_GetSysClockFreq()
      3) each time HAL_RCC_ClockConfig() is called to configure the system clock frequency  
  -----------------------------------------------------------------------------*/
  /* Initialize TIM15 peripheral as follows:
      + Period = TimerPeriod (To have an output frequency equal to 17.570 KHz)
      + Repetition Counter = 3
      + Prescaler = 0
      + ClockDivision = 0
      + Counter direction = Up
  */
  TimHandle.Instance = TIMx;
  
  TimHandle.Init.Period            = uhTimerPeriod;
  TimHandle.Init.RepetitionCounter = 3;
  TimHandle.Init.Prescaler         = 0;
  TimHandle.Init.ClockDivision     = 0;
  TimHandle.Init.CounterMode       = TIM_COUNTERMODE_UP;
  TimHandle.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
  if(HAL_TIM_PWM_Init(&TimHandle) != HAL_OK)
  {
    /* Initialization Error */
    Error_Handler();
  }

  /*##-2- Configure the PWM channel 1 ########################################*/ 
  sConfig.OCMode       = TIM_OCMODE_PWM1;
  sConfig.OCPolarity   = TIM_OCPOLARITY_HIGH;
  sConfig.Pulse        = aCCValue_Buffer[0];
  sConfig.OCNPolarity  = TIM_OCNPOLARITY_HIGH;
  sConfig.OCFastMode   = TIM_OCFAST_DISABLE;
  sConfig.OCIdleState  = TIM_OCIDLESTATE_RESET;
  sConfig.OCNIdleState = TIM_OCNIDLESTATE_RESET;
  if(HAL_TIM_PWM_ConfigChannel(&TimHandle, &sConfig, TIM_CHANNEL_1) != HAL_OK)
  {
    /* Configuration Error */
    Error_Handler();
  }
  
  /*##-3- Start PWM signal generation in DMA mode ############################*/ 
  if(HAL_TIM_PWM_Start_DMA(&TimHandle, TIM_CHANNEL_1, aCCValue_Buffer, 3) != HAL_OK)
  {
    /* Starting PWM generation Error */
    Error_Handler();
  }

  while (1)
  {
  }
    
}

/**
  * @brief  This function is executed in case of error occurrence.
  * @param  None
  * @retval None
  */
static void Error_Handler(void)
{
  /* Turn LED3 on */
  BSP_LED_On(LED3);
  while (1)
  {
  }
}

/**
  * @brief  System Clock Configuration
  *         The system Clock is configured as follow : 
  *            System Clock source            = PLL (HSE)
  *            SYSCLK(Hz)                     = 72000000
  *            HCLK(Hz)                       = 72000000
  *            AHB Prescaler                  = 1
  *            APB1 Prescaler                 = 2
  *            APB2 Prescaler                 = 1
  *            HSE Frequency(Hz)              = 8000000
  *            HSE PREDIV                     = 1
  *            PLLMUL                         = RCC_PLL_MUL9 (9)
  *            Flash Latency(WS)              = 2
  * @param  None
  * @retval None
  */
static void SystemClock_Config(void)
{
  RCC_ClkInitTypeDef RCC_ClkInitStruct;
  RCC_OscInitTypeDef RCC_OscInitStruct;
  
  /* Enable HSE Oscillator and activate PLL with HSE as source */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct)!= HAL_OK)
  {
    Error_Handler();
  }

  /* 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;
  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2)!= HAL_OK)
  {
    Error_Handler();
  }
}


#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****/