2019-10-18 16:39:08 +01:00

259 lines
8.7 KiB
C

/**
******************************************************************************
* @file TIM/TIM_DMA/Src/main.c
* @author MCD Application Team
* @brief This sample code shows how to use DMA with TIM1 Update request to
* transfer Data from memory to TIM1 Capture Compare Register 3 (CCR3).
******************************************************************************
* @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 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)
{
/* This sample code shows how to use DMA with TIM1 Update request to transfer
Data from memory to TIM1 Capture Compare Register 3 (CCR3), through the
STM32F3xx HAL API. To proceed, 3 steps are required */
/* STM32F3xx HAL library initialization:
- Configure the Flash prefetch
- Configure the Systick to generate an interrupt each 1 msec
- Set NVIC Group Priority to 4
- Low Level Initialization
*/
HAL_Init();
/* Configure the system clock to 64 MHz */
SystemClock_Config();
/* Configure LED2 */
BSP_LED_Init(LED2);
/* Compute the value of ARR regiter to generate signal frequency at 17.57 Khz */
uwTimerPeriod = (uint32_t)((SystemCoreClock / 17570) - 1);
/* Compute CCR1 value to generate a duty cycle at 75% */
aCCValue_Buffer[0] = (uint32_t)(((uint32_t) 75 * (uwTimerPeriod - 1)) / 100);
/* Compute CCR2 value to generate a duty cycle at 50% */
aCCValue_Buffer[1] = (uint32_t)(((uint32_t) 50 * (uwTimerPeriod - 1)) / 100);
/* Compute CCR3 value to generate a duty cycle at 25% */
aCCValue_Buffer[2] = (uint32_t)(((uint32_t) 25 * (uwTimerPeriod - 1)) / 100);
/*##-1- Configure the TIM peripheral #######################################*/
/* ---------------------------------------------------------------------------
TIM1 input clock (TIM1CLK) is set to APB2 clock (PCLK2), since APB2
prescaler is 1.
TIM1CLK = PCLK2
PCLK2 = HCLK
=> TIM1CLK = HCLK = SystemCoreClock
TIM1CLK = SystemCoreClock, Prescaler = 0, TIM1 counter clock = SystemCoreClock
SystemCoreClock is set to 64 MHz for STM32F3xx devices.
The objective is to configure TIM1 channel 3 to generate a PWM
signal with a frequency equal to 17.57 KHz:
- TIM1_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 TIM1 Repetition counter,
each 4 Update Requests, the TIM1 Channel 3 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 TIM1 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 = uwTimerPeriod;
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 3 ########################################*/
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_3) != HAL_OK)
{
/* Configuration Error */
Error_Handler();
}
/*##-3- Start PWM signal generation in DMA mode ############################*/
if (HAL_TIM_PWM_Start_DMA(&TimHandle, TIM_CHANNEL_3, aCCValue_Buffer, 3) != HAL_OK)
{
/* Starting 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 LED2 on */
BSP_LED_On(LED2);
while (1)
{
}
}
/**
* @brief System Clock Configuration
* The system Clock is configured as follow :
* System Clock source = PLL (HSI)
* SYSCLK(Hz) = 64000000
* HCLK(Hz) = 64000000
* AHB Prescaler = 1
* APB1 Prescaler = 2
* APB2 Prescaler = 1
* HSI Frequency(Hz) = 8000000
* PREDIV = RCC_PREDIV_DIV2 (2)
* PLLMUL = RCC_PLL_MUL16 (16)
* Flash Latency(WS) = 2
* @param None
* @retval None
*/
void SystemClock_Config(void)
{
RCC_ClkInitTypeDef RCC_ClkInitStruct;
RCC_OscInitTypeDef RCC_OscInitStruct;
/* HSI Oscillator already ON after system reset, activate PLL with HSI as source */
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_NONE;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
RCC_OscInitStruct.PLL.PREDIV = RCC_PREDIV_DIV2;
RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL16;
RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
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_DIV2;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2)!= HAL_OK)
{
/* Initialization Error */
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
/**
* @}
*/
/**
* @}
*/
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/