/**
  ******************************************************************************
  * @file    TIM/TIM_DMABurst/Src/main.c
  * @author  MCD Application Team
  * @brief   This sample code shows how to use DMA with TIM2 Update request to
  *          transfer Data from memory to TIM2 Capture Compare Register 3
  *          (CCR3), through the STM32L0xx HAL API.
  ******************************************************************************
  * @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 TIM_DMABurst
  * @{
  */

/* 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 aSRC_Buffer[3] = {0x0FFF, 0x0000, 0x0555};

/* Timer Period*/
uint32_t uwTimerPeriod  = 0;

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void Error_Handler(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 to 2 MHz */
  SystemClock_Config();

  /* Configure LED2 */
  BSP_LED_Init(LED2);

/*##-1- Configure the TIM peripheral #######################################*/ 
  /* -----------------------------------------------------------------------
    TIM2 Configuration: generate 1 PWM signal using the DMA burst mode:
   
    TIM2 input clock (TIM2CLK) is set to APB1 clock (PCLK1), since APB1
    prescaler is 1.
    TIM1CLK = PCLK1
    PCLK1 = HCLK
    => TIM1CLK = HCLK = SystemCoreClock
    
    To get TIM2 counter clock at 2.1 MHz, the prescaler is computed as follows:
      Prescaler = (TIM2CLK / TIM2 counter clock) - 1
      Prescaler = (SystemCoreClock /2.1 MHz) - 1
  
    The TIM2 Frequency = TIM2 counter clock/(ARR + 1)
                       = 2.1 MHz / 4096 = 0.51 KHz
    TIM2 Channel1 duty cycle = (TIM2_CCR1/ TIM2_ARR)* 100 = 33.33%
  
    Note: 
     SystemCoreClock variable holds HCLK frequency and is defined in system_stm32l0xx.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  
  ----------------------------------------------------------------------- */
  
  TimHandle.Instance = TIM2;
  
  TimHandle.Init.Period            = 0xFFFF;
  TimHandle.Init.Prescaler         = 0;
  TimHandle.Init.ClockDivision     = 0;
  TimHandle.Init.CounterMode       = TIM_COUNTERMODE_UP;
  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      = 0xFFF;
  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(&TimHandle, TIM_CHANNEL_1) != HAL_OK)
  {
    /* Starting PWM generation Error */
    Error_Handler();
  }
  
  /*##-4- Start DMA Burst transfer ###########################################*/ 
  HAL_TIM_DMABurst_WriteStart(&TimHandle, TIM_DMABASE_ARR, TIM_DMA_UPDATE,
                              (uint32_t*)aSRC_Buffer, TIM_DMABURSTLENGTH_3TRANSFERS);
  
  /* Infinite loop */
  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)
  {
  }
}


/**
  * @brief  System Clock Configuration
  *         The system Clock is configured as follow : 
  *            System Clock source            = MSI
  *            SYSCLK(Hz)                     = 2000000
  *            HCLK(Hz)                       = 2000000
  *            AHB Prescaler                  = 1
  *            APB1 Prescaler                 = 1
  *            APB2 Prescaler                 = 1
  *            Flash Latency(WS)              = 0
  *            Main regulator output voltage  = Scale3 mode
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  
  /* 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_DIV1;
  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); 
  }
  /* 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_SCALE3);
  
  /* Disable Power Control clock */
  __HAL_RCC_PWR_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****/
