深入理解STM32中的DMA技术

DMA介绍

DMA(Direct MemoryAccess,直接存储器访问)提供在外设与内存、存储器和存储器、外设与外设之间的高速数据传输使用。它允许不同速度的硬件装置来沟通,而不需要依赖于CPU,在这个时间中,CPU对于内存的工作来说就无法使用。

DMA的意义

  • 数据搬运的工作比较耗时间。

  • 数据搬运工作时效要求高(有数据来就要搬走) 。

  • 没啥技术含量(CPU节约出来的时间可以处理更重要的事)。

  • DMA是数据搬运工,代替CPU搬运数据,为CPU节省资源让CPU做其他操作。

  • DMA搬运的数据

  • 存储器:存储器包括自身的闪存(flash)或者内存(SRAM)以及外设的存储设备都可以作为访问的源或者目标。

  • 外设:外设指的是spi、usart、iic、adc 等基于APB1、APB2或AHB时钟的外设。

  • DMA搬运的地点

  • 存储器–>存储器(例如:复制某特别大的数据buf)

  • 存储–>外设(例:将某数据buf写入串口TDR寄存器)

  • 外设–>存储器(例如:将串口RDR寄存器写入某数据buf)

  • DMA通道

    STM32F103C8T6有2个DMA控制器,DMA1有7个通道,DMA2有5个通道,一个通道每次只能搬运一个外设的数据,如果同时有多个外设的DMA请求,则按照通道优先级进行响应。

    仲裁器

  • 仲裁器会通过DMA通道请求的优先级来启动对外设/内存的访问,也就是哪个通道的优先级最高,DMA就先响应哪个通道。

  • DMA通道优先级管理由软件优先级和硬件优先级组成:

    1. 软件优先级:每个通道的优先权可以在DMA_CCRx寄存器中设置,有4个等级:

  • 最高优先级(Very High)

  • 高优先级(High)

  • 中等优先级(Medium)

  • 低优先级(Low)

    1. 硬件优先级:如果2个请求有相同的软件优先级,则较低编号的通道比较高编号的通道有较高的优先权。

    控制器

    DMA1

    DMA2

    DMA处理

    在发生一个DMA请求事件后,外设向DMA控制器发送一个请求信号。DMA控制器根据通道优先级处理请求。当DMA控制器开始访问发出DMA请求的外设时,DMA控制器立即发送给外设一个应答信号。当外设从DMA控制器得到应答信号时,立即释放它的DMA请求。一旦外设释放了这个请求,DMA控制器同时撤销应答信号。如果有更多的请求时,外设可以启动下一个周期。

    DMA传输的三个操作

    1. 从外设数据寄存器或者从当前外设/存储器地址寄存器指示的存储器地址取数据,第一次传输时的开始地址是DMA_CPARx或DMA_CMARx寄存器指定的外设基地址或存储器单元。(从旧地点取数据)

    1. 存数据到外设数据寄存器或者当前外设/存储器地址寄存器指示的存储器地址,第一次传输时的开始地址是DMA_CPARx或DMA_CMARx寄存器指定的外设基地址或存储器单元。(到新地点存数据)

    1. 执行一次DMA_CNDTRx寄存器的递减操作,该寄存器包含未完成的操作数目。(操作数递减1次)

    DMA传输的方式

    正常模式(DMA Mode Normal)

  • 一次DMA数据传输完后,停止DMA传送,也就是只传输一次。

  • 要开始新的DMA传输,需要在关闭DMA通道的情况下,在DMA CNDTRx寄存器中重新写入传输数目。

  • 循环传输模式(DMA Mode Circular)

  • 当传输结束时,硬件自动会将传输数据量寄存器进行重装,进行下一轮的数据传输。 也就是多次传输模式。

  • 主要用于处理循环缓冲区和连续的数据传输。

  • 指针增量模式

    外设和存储器指针在每次传输后可以自动向后递增或保持常量。当设置为增量模式时,下一个要传输的地址将是前一个地址加上增量值。

  • 源指针和目标指针都设置为增量模式

  • 源指针设置为增量模式

  • 一般设计存储器的都开启指针增量模式

  • DMA中断

    每个DMA通道都有3个事件(DMA半传输、DMA传输完成和DMA传输错误),这3个事件都可以成为一个单独的中断请求。

    中断事件

    事件标志位

    使能控制位

    DMA半传输

    HTIF

    HTIE

    DMA传输完成

    TCIF

    TCIE

    DMA传输错误

    TEIF

    TEIE

    DMA实验1(存储器 -> 存储器)

    使用DMA的方式将数组A的内容复制到数组B中,搬运完之后将数组B的内容通过串口打印到屏幕,同时每隔0.5s翻转一次LED1的电平。

    STM32的hal库关于DMA的函数

    HAL_DMA_Start()

    开启某个DMA通道的数据运输。

    原型:HAL_StatusTypeDef HAL_DMA_Start(DMA_HandleTypeDef *hdma, uint32_t SrcAddress, uint32_t DstAddress, uint32_t DataLength)

    参数:

    DMA_HandleTypeDef *hdma:DMA通道句柄

    uint32_t SrcAddress:源数据地址

    DstAddress:目标数据地址

    DataLength:数据长度

    实例:


    #define BUF_SIZE 16


    uint32_t srcBuf[BUF_SIZE] = {


    0x00000000,0x11111111,0x22222222,0x33333333,


    0x44444444,0x55555555,0x66666666,0x77777777,


    0x88888888,0x99999999,0xaaaaaaaa,0xbbbbbbbb,


    0xcccccccc,0xdddddddd,0xeeeeeeee,0xffffffff


    };


    uint32_t desBuf[BUF_SIZE];

    HAL_DMA_Start(&hdma_memtomem_dma1_channel1,(uint32_t)srcBuf,(uint32_t)desBuf,sizeof(uint32_t) * BUF_SIZE); //开启DMA1通道1的数据传输

    __HAL_DMA_GET_FLAG

    检测某个DMA通道的数据传输情况。

    原型:__HAL_DMA_GET_FLAG(DMA_HandleTypeDef *hdma,__FLAG__)

    参数:

    DMA_HandleTypeDef *hdma:DMA通道句柄

    __FLAG__:

    DMA_FLAG_TCx:传输完成标志

    DMA_FLAG_HTx:半传输完成标志

    DMA_FLAG_TEx:传输错误标志

    DMA_FLAG_GLx:全局中断标志

    实例:__HAL_DMA_GET_FLAG(&hdma_memtomem_dma1_channel1,DMA_FLAG_TC1) //检测DMA1通道1的数据传输是否完成,完成返回RESET

    使用STM32CubeMX创建工程

    配置SYS

    配置RCC

    配置GPIO

    PB8配置成输出高电平

    配置串口信息(UART1)

    配置DMA

    使用DMA1的通道1,传输方向为内存到内存

    配置工程名称、工程路径

    选择固件库

    生成工程

    使用MicroLIB库

    main.c文件编写

    /* USER CODE BEGIN Header */
    /**
      ******************************************************************************
      * @file           : main.c
      * @brief          : Main program body
      ******************************************************************************
      * @attention
      *
      * Copyright (c) 2023 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.
      *
      ******************************************************************************
      */
    /* USER CODE END Header */
    /* Includes ------------------------------------------------------------------*/
    #include "main.h"
    #include "dma.h"
    #include "usart.h"
    #include "gpio.h"
    
    /* Private includes ----------------------------------------------------------*/
    /* USER CODE BEGIN Includes */
    #include <stdio.h>
    
    #define BUF_SIZE 16
    /* USER CODE END Includes */
    
    /* Private typedef -----------------------------------------------------------*/
    /* USER CODE BEGIN PTD */
    
    /* USER CODE END PTD */
    
    /* Private define ------------------------------------------------------------*/
    /* USER CODE BEGIN PD */
    /* USER CODE END PD */
    
    /* Private macro -------------------------------------------------------------*/
    /* USER CODE BEGIN PM */
    
    /* USER CODE END PM */
    
    /* Private variables ---------------------------------------------------------*/
    
    /* USER CODE BEGIN PV */
    
    /* USER CODE END PV */
    
    /* Private function prototypes -----------------------------------------------*/
    void SystemClock_Config(void);
    /* USER CODE BEGIN PFP */
    
    /* USER CODE END PFP */
    
    /* Private user code ---------------------------------------------------------*/
    /* USER CODE BEGIN 0 */
    
    //重写stdio.h文件中的prinft()里的fputc()函数
    int fputc(int my_data,FILE *p)
    {
        unsigned char temp = my_data;
        //改写后,使用printf()函数会将数据通过串口一发送出去
        HAL_UART_Transmit(&huart1,&temp,1,0xffff);  //0xfffff为最大超时时间
        return my_data;
    }
    
    //源数组
    uint32_t srcBuf[BUF_SIZE] = {
        0x00000000,0x11111111,0x22222222,0x33333333,
        0x44444444,0x55555555,0x66666666,0x77777777,
        0x88888888,0x99999999,0xaaaaaaaa,0xbbbbbbbb,
        0xcccccccc,0xdddddddd,0xeeeeeeee,0xffffffff
    };
    
    //目标数组
    uint32_t desBuf[BUF_SIZE];
    
    /* USER CODE END 0 */
    
    /**
      * @brief  The application entry point.
      * @retval int
      */
    int main(void)
    {
      /* USER CODE BEGIN 1 */
        int i = 0;
      /* USER CODE END 1 */
    
      /* MCU Configuration--------------------------------------------------------*/
    
      /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
      HAL_Init();
    
      /* USER CODE BEGIN Init */
    
      /* USER CODE END Init */
    
      /* Configure the system clock */
      SystemClock_Config();
    
      /* USER CODE BEGIN SysInit */
    
      /* USER CODE END SysInit */
    
      /* Initialize all configured peripherals */
      MX_GPIO_Init();
      MX_DMA_Init();
      MX_USART1_UART_Init();
      /* USER CODE BEGIN 2 */
    
        //①:开启DMA1通道1的数据传输
        HAL_DMA_Start(&hdma_memtomem_dma1_channel1,(uint32_t)srcBuf,(uint32_t)desBuf,sizeof(uint32_t) * BUF_SIZE);  //DMA1通道1的数据开始传输
        
        //②:等待DMA1通道1数据传输完成
        while(__HAL_DMA_GET_FLAG(&hdma_memtomem_dma1_channel1,DMA_FLAG_TC1) == RESET);  //等待某个通道的数据传输完成,flag标志位置位RESET
        
        //③:打印数组内容
        for(i = 0;i < BUF_SIZE;i++){
            printf("Buf[%d] = %X\r\n",i,desBuf[i]);
        }
        
      /* USER CODE END 2 */
    
      /* Infinite loop */
      /* USER CODE BEGIN WHILE */
      while (1)
      {
        /* USER CODE END WHILE */
    
        /* USER CODE BEGIN 3 */
            
            HAL_GPIO_TogglePin(GPIOB,GPIO_PIN_8);
            HAL_Delay(500);
            
      }
      /* USER CODE END 3 */
    }
    
    /**
      * @brief System Clock Configuration
      * @retval None
      */
    void SystemClock_Config(void)
    {
      RCC_OscInitTypeDef RCC_OscInitStruct = {0};
      RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
    
      /** Initializes the RCC Oscillators according to the specified parameters
      * in the RCC_OscInitTypeDef structure.
      */
      RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
      RCC_OscInitStruct.HSEState = RCC_HSE_ON;
      RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
      RCC_OscInitStruct.HSIState = RCC_HSI_ON;
      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();
      }
    
      /** Initializes the CPU, AHB and APB buses clocks
      */
      RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                                  |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();
      }
    }
    
    /* USER CODE BEGIN 4 */
    
    /* USER CODE END 4 */
    
    /**
      * @brief  This function is executed in case of error occurrence.
      * @retval None
      */
    void Error_Handler(void)
    {
      /* USER CODE BEGIN Error_Handler_Debug */
      /* User can add his own implementation to report the HAL error return state */
      __disable_irq();
      while (1)
      {
      }
      /* USER CODE END Error_Handler_Debug */
    }
    
    #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 CODE BEGIN 6 */
      /* 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) */
      /* USER CODE END 6 */
    }
    #endif /* USE_FULL_ASSERT */
    

    DMA实验2(存储器 -> 外设:UART1)

    使用DMA的方式将存储器的内容发送到串口1,同时每隔0.5s翻转一次LED1的电平。

    STM32的hal库关于DMA的函数

    HAL_UART_Transmit_DMA()

    使用DMA将其他地方的数据搬运到串口。

    原型:HAL_StatusTypeDef HAL_UART_Transmit_DMA(UART_HandleTypeDef *huart, uint8_t *pData, uint16_t Size)

    参数:

    UART_HandleTypeDef *huart:串口句柄

    uint8_t *pData:传输数据地址

    uint16_t Size:传输数据大小

    实例:

    #define BUF_SIZE 1000

    unsigned char sendBuf[BUF_SIZE] = {0};

    for(i = 0;i < BUF_SIZE;i++){

    sendBuf[i] = 'h';

    }

    HAL_UART_Transmit_DMA(&huart1,sendBuf,BUF_SIZE); //将数据通过串口DMA发送

    使用STM32CubeMX创建工程

    配置SYS

    配置RCC

    配置GPIO

    PB8配置成输出高电平

    配置串口信息(UART1)

    配置DMA

  • 使用DMA1的通道4,传输方向为内存到外设(串口1)

  • 配置成正常模式只会向串口发送一次数组内容,而配置成循环模式将不断向串口发送数组内容

  • 配置工程名称、工程路径

    选择固件库

    生成工程

    使用MicroLIB库

    main.c文件编写

    /* USER CODE BEGIN Header */
    /**
      ******************************************************************************
      * @file           : main.c
      * @brief          : Main program body
      ******************************************************************************
      * @attention
      *
      * Copyright (c) 2023 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.
      *
      ******************************************************************************
      */
    /* USER CODE END Header */
    /* Includes ------------------------------------------------------------------*/
    #include "main.h"
    #include "dma.h"
    #include "usart.h"
    #include "gpio.h"
    
    /* Private includes ----------------------------------------------------------*/
    /* USER CODE BEGIN Includes */
    
    #define BUF_SIZE 1000
    
    /* USER CODE END Includes */
    
    /* Private typedef -----------------------------------------------------------*/
    /* USER CODE BEGIN PTD */
    
    /* USER CODE END PTD */
    
    /* Private define ------------------------------------------------------------*/
    /* USER CODE BEGIN PD */
    /* USER CODE END PD */
    
    /* Private macro -------------------------------------------------------------*/
    /* USER CODE BEGIN PM */
    
    /* USER CODE END PM */
    
    /* Private variables ---------------------------------------------------------*/
    
    /* USER CODE BEGIN PV */
    
    /* USER CODE END PV */
    
    /* Private function prototypes -----------------------------------------------*/
    void SystemClock_Config(void);
    /* USER CODE BEGIN PFP */
    
    /* USER CODE END PFP */
    
    /* Private user code ---------------------------------------------------------*/
    /* USER CODE BEGIN 0 */
    
    //待发送数据
    unsigned char sendBuf[BUF_SIZE] = {0};
    
    /* USER CODE END 0 */
    
    /**
      * @brief  The application entry point.
      * @retval int
      */
    int main(void)
    {
      /* USER CODE BEGIN 1 */
        int i = 0;
      /* USER CODE END 1 */
    
      /* MCU Configuration--------------------------------------------------------*/
    
      /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
      HAL_Init();
    
      /* USER CODE BEGIN Init */
    
      /* USER CODE END Init */
    
      /* Configure the system clock */
      SystemClock_Config();
    
      /* USER CODE BEGIN SysInit */
    
      /* USER CODE END SysInit */
    
      /* Initialize all configured peripherals */
      MX_GPIO_Init();
      MX_DMA_Init();
      MX_USART1_UART_Init();
      /* USER CODE BEGIN 2 */
    
        //①:准备数据
        for(i = 0;i < BUF_SIZE;i++){
            sendBuf[i] = 'h';
        }
    
        //②:将数据通过串口DMA发送
        HAL_UART_Transmit_DMA(&huart1,sendBuf,BUF_SIZE);  //将数据通过串口DMA发送
        
      /* USER CODE END 2 */
    
      /* Infinite loop */
      /* USER CODE BEGIN WHILE */
      while (1)
      {
        /* USER CODE END WHILE */
    
        /* USER CODE BEGIN 3 */
            
            HAL_GPIO_TogglePin(GPIOB,GPIO_PIN_8);
            
            HAL_Delay(500);
            
      }
      /* USER CODE END 3 */
    }
    
    /**
      * @brief System Clock Configuration
      * @retval None
      */
    void SystemClock_Config(void)
    {
      RCC_OscInitTypeDef RCC_OscInitStruct = {0};
      RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
    
      /** Initializes the RCC Oscillators according to the specified parameters
      * in the RCC_OscInitTypeDef structure.
      */
      RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
      RCC_OscInitStruct.HSEState = RCC_HSE_ON;
      RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
      RCC_OscInitStruct.HSIState = RCC_HSI_ON;
      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();
      }
    
      /** Initializes the CPU, AHB and APB buses clocks
      */
      RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                                  |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();
      }
    }
    
    /* USER CODE BEGIN 4 */
    
    /* USER CODE END 4 */
    
    /**
      * @brief  This function is executed in case of error occurrence.
      * @retval None
      */
    void Error_Handler(void)
    {
      /* USER CODE BEGIN Error_Handler_Debug */
      /* User can add his own implementation to report the HAL error return state */
      __disable_irq();
      while (1)
      {
      }
      /* USER CODE END Error_Handler_Debug */
    }
    
    #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 CODE BEGIN 6 */
      /* 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) */
      /* USER CODE END 6 */
    }
    #endif /* USE_FULL_ASSERT */
    

    DMA实验3(外设:UART1 -> 存储器)

    使用DMA的方式将串口1接收缓存寄存器的数据搬运到存储器中,再通过串口打印存储器数据,同时每隔0.5s翻转一次LED1的电平。

    实现流程

  • 使能IDLE空闲中断,当检测到串口空闲时(串口每接收完一份数据)就会调用一次串口中断。

  • 将串口数据使用DMA搬运到内存。

  • 在串口的中断处理函数USART1_IRQHandler()中将内存的数据显示在串口中:

    1. 判断是否是串口空闲触发的中断,即判断IDLE标志位是否置位SET。

    1. 停止DMA从串口搬运数据到内存。

    1. 获取DMA从串口搬运的数据大小。

  • 将DMA从串口搬运的内存数据打印在串口。

  • 重新将串口数据使用DMA搬运到内存,准备下一次的重复操作。

  • STM32的hal库关于DMA的函数

    HAL_UART_Receive_DMA()

    使用DMA搬运串口数据到其他地方

    原型:

    HAL_StatusTypeDef HAL_UART_Receive_DMA(UART_HandleTypeDef *huart, uint8_t *pData, uint16_t Size)

    参数:

    UART_HandleTypeDef *huart:串口句柄

    uint8_t *pData:传输数据地址

    uint16_t Size:传输数据大小

    实例:

    #define BUF_SIZE 1000

    uint8_t rcvBuf[BUF_SIZE] = {0};

    HAL_UART_Receive_DMA(&huart1,rcvBuf,BUF_SIZE); //将串口数据通过DMA接收到内存

    __HAL_UART_ENABLE_IT()

    使能某个串口标志位的中断。

    原型:

    __HAL_UART_ENABLE_IT(__HANDLE__, __INTERRUPT__)

    参数:

    __HANDLE__:串口句柄

    __INTERRUPT__:

    UART_IT_CTS: CTS change interrupt

    UART_IT_LBD: LIN Break detection interrupt

    UART_IT_TXE: Transmit Data Register empty interrupt

    UART_IT_TC: Transmission complete interrupt

    UART_IT_RXNE: Receive Data register not empty interrupt

    UART_IT_IDLE: 串口空闲中断

    UART_IT_PE: Parity Error interrupt

    UART_IT_ERR: Error interrupt(Frame error, noise error, overrun error)

    实例:

    __HAL_UART_ENABLE_IT(&huart1,UART_IT_IDLE); //使能IDLE空闲中断

    __HAL_UART_GET_FLAG()

    获取串口的某个标志位的状态

    原型:

    #define __HAL_UART_GET_FLAG(__HANDLE__, __FLAG__) (((__HANDLE__)->Instance->SR & (__FLAG__)) == (__FLAG__))

    参数:

    _HANDLE__:串口句柄

    __FLAG__:

    UART_FLAG_CTS: CTS Change flag (not available for UART4 and UART5)

    UART_FLAG_LBD: LIN Break detection flag

    UART_FLAG_TXE: Transmit data register empty flag

    UART_FLAG_TC: Transmission Complete flag

    UART_FLAG_RXNE: Receive data register not empty flag

    UART_FLAG_IDLE: 串口空闲标志位

    UART_FLAG_ORE: Overrun Error flag

    UART_FLAG_NE: Noise Error flag

    UART_FLAG_FE: Framing Error flag

    UART_FLAG_PE: Parity Error flag

    实例:

    __HAL_UART_GET_FLAG(&huart1,UART_FLAG_IDLE) //获取IDLE标志位的状态,如果被置位了为SET

    HAL_UART_DMAStop()

    停止DMA从串口搬运数据或者停止DMA搬运数据到串口。

    原型:

    HAL_StatusTypeDef HAL_UART_DMAStop(UART_HandleTypeDef *huart)

    参数:

    UART_HandleTypeDef *huart:串口句柄

    实例:

    HAL_UART_DMAStop(&huart1); //停止DMA从串口搬运数据

    使用STM32CubeMX创建工程

    配置SYS

    配置RCC

    配置GPIO

    PB8配置成输出高电平

    配置串口信息(UART1)

    配置DMA

    使用DMA1的通道5,传输方向为外设(串口1)到内存

    配置工程名称、工程路径

    选择固件库

    生成工程

    使用MicroLIB库

    main.c文件编写

    /* USER CODE BEGIN Header */
    /**
      ******************************************************************************
      * @file           : main.c
      * @brief          : Main program body
      ******************************************************************************
      * @attention
      *
      * Copyright (c) 2023 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.
      *
      ******************************************************************************
      */
    /* USER CODE END Header */
    /* Includes ------------------------------------------------------------------*/
    #include "main.h"
    #include "dma.h"
    #include "usart.h"
    #include "gpio.h"
    
    /* Private includes ----------------------------------------------------------*/
    /* USER CODE BEGIN Includes */
    #define BUF_SIZE 100
    /* USER CODE END Includes */
    
    /* Private typedef -----------------------------------------------------------*/
    /* USER CODE BEGIN PTD */
    
    /* USER CODE END PTD */
    
    /* Private define ------------------------------------------------------------*/
    /* USER CODE BEGIN PD */
    /* USER CODE END PD */
    
    /* Private macro -------------------------------------------------------------*/
    /* USER CODE BEGIN PM */
    
    /* USER CODE END PM */
    
    /* Private variables ---------------------------------------------------------*/
    
    /* USER CODE BEGIN PV */
    
    /* USER CODE END PV */
    
    /* Private function prototypes -----------------------------------------------*/
    void SystemClock_Config(void);
    /* USER CODE BEGIN PFP */
    
    /* USER CODE END PFP */
    
    /* Private user code ---------------------------------------------------------*/
    /* USER CODE BEGIN 0 */
    
    uint8_t rcvBuf[BUF_SIZE] = {0};  //接收数据缓存数组
    uint8_t rcvLen = 0;  //接收一份数据的长度
    
    /* USER CODE END 0 */
    
    /**
      * @brief  The application entry point.
      * @retval int
      */
    int main(void)
    {
      /* USER CODE BEGIN 1 */
    
      /* USER CODE END 1 */
    
      /* MCU Configuration--------------------------------------------------------*/
    
      /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
      HAL_Init();
    
      /* USER CODE BEGIN Init */
    
      /* USER CODE END Init */
    
      /* Configure the system clock */
      SystemClock_Config();
    
      /* USER CODE BEGIN SysInit */
    
      /* USER CODE END SysInit */
    
      /* Initialize all configured peripherals */
      MX_GPIO_Init();
      MX_DMA_Init();
      MX_USART1_UART_Init();
      /* USER CODE BEGIN 2 */
    
        //使能IDLE空闲中断,当检测到串口空闲时就会调用串口中断
        __HAL_UART_ENABLE_IT(&huart1,UART_IT_IDLE);
        
        //DMA搬运串口数据到内存
        HAL_UART_Receive_DMA(&huart1,rcvBuf,BUF_SIZE);
    
      /* USER CODE END 2 */
    
      /* Infinite loop */
      /* USER CODE BEGIN WHILE */
      while (1)
      {
        /* USER CODE END WHILE */
    
        /* USER CODE BEGIN 3 */
            
            HAL_GPIO_TogglePin(GPIOB,GPIO_PIN_8);
            HAL_Delay(500);
            
      }
      /* USER CODE END 3 */
    }
    
    /**
      * @brief System Clock Configuration
      * @retval None
      */
    void SystemClock_Config(void)
    {
      RCC_OscInitTypeDef RCC_OscInitStruct = {0};
      RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
    
      /** Initializes the RCC Oscillators according to the specified parameters
      * in the RCC_OscInitTypeDef structure.
      */
      RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
      RCC_OscInitStruct.HSEState = RCC_HSE_ON;
      RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
      RCC_OscInitStruct.HSIState = RCC_HSI_ON;
      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();
      }
    
      /** Initializes the CPU, AHB and APB buses clocks
      */
      RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                                  |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();
      }
    }
    
    /* USER CODE BEGIN 4 */
    
    /* USER CODE END 4 */
    
    /**
      * @brief  This function is executed in case of error occurrence.
      * @retval None
      */
    void Error_Handler(void)
    {
      /* USER CODE BEGIN Error_Handler_Debug */
      /* User can add his own implementation to report the HAL error return state */
      __disable_irq();
      while (1)
      {
      }
      /* USER CODE END Error_Handler_Debug */
    }
    
    #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 CODE BEGIN 6 */
      /* 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) */
      /* USER CODE END 6 */
    }
    #endif /* USE_FULL_ASSERT */
    

    stm32f1xx_it.c文件编写

    /* USER CODE BEGIN Header */
    /**
      ******************************************************************************
      * @file    stm32f1xx_it.c
      * @brief   Interrupt Service Routines.
      ******************************************************************************
      * @attention
      *
      * Copyright (c) 2023 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.
      *
      ******************************************************************************
      */
    /* USER CODE END Header */
    
    /* Includes ------------------------------------------------------------------*/
    #include "main.h"
    #include "stm32f1xx_it.h"
    /* Private includes ----------------------------------------------------------*/
    /* USER CODE BEGIN Includes */
    /* USER CODE END Includes */
    
    /* Private typedef -----------------------------------------------------------*/
    /* USER CODE BEGIN TD */
    
    /* USER CODE END TD */
    
    /* Private define ------------------------------------------------------------*/
    /* USER CODE BEGIN PD */
    
    /* USER CODE END PD */
    
    /* Private macro -------------------------------------------------------------*/
    /* USER CODE BEGIN PM */
    
    /* USER CODE END PM */
    
    /* Private variables ---------------------------------------------------------*/
    /* USER CODE BEGIN PV */
    
    /* USER CODE END PV */
    
    /* Private function prototypes -----------------------------------------------*/
    /* USER CODE BEGIN PFP */
    
    /* USER CODE END PFP */
    
    /* Private user code ---------------------------------------------------------*/
    /* USER CODE BEGIN 0 */
    
    extern uint8_t rcvBuf[BUF_SIZE];  //接收数据缓存数组
    extern uint8_t rcvLen;  //接收一帧数据的长度
    
    /* USER CODE END 0 */
    
    /* External variables --------------------------------------------------------*/
    extern DMA_HandleTypeDef hdma_usart1_rx;
    extern DMA_HandleTypeDef hdma_usart1_tx;
    extern UART_HandleTypeDef huart1;
    /* USER CODE BEGIN EV */
    
    /* USER CODE END EV */
    
    /******************************************************************************/
    /*           Cortex-M3 Processor Interruption and Exception Handlers          */
    /******************************************************************************/
    /**
      * @brief This function handles Non maskable interrupt.
      */
    void NMI_Handler(void)
    {
      /* USER CODE BEGIN NonMaskableInt_IRQn 0 */
    
      /* USER CODE END NonMaskableInt_IRQn 0 */
      /* USER CODE BEGIN NonMaskableInt_IRQn 1 */
      while (1)
      {
      }
      /* USER CODE END NonMaskableInt_IRQn 1 */
    }
    
    /**
      * @brief This function handles Hard fault interrupt.
      */
    void HardFault_Handler(void)
    {
      /* USER CODE BEGIN HardFault_IRQn 0 */
    
      /* USER CODE END HardFault_IRQn 0 */
      while (1)
      {
        /* USER CODE BEGIN W1_HardFault_IRQn 0 */
        /* USER CODE END W1_HardFault_IRQn 0 */
      }
    }
    
    /**
      * @brief This function handles Memory management fault.
      */
    void MemManage_Handler(void)
    {
      /* USER CODE BEGIN MemoryManagement_IRQn 0 */
    
      /* USER CODE END MemoryManagement_IRQn 0 */
      while (1)
      {
        /* USER CODE BEGIN W1_MemoryManagement_IRQn 0 */
        /* USER CODE END W1_MemoryManagement_IRQn 0 */
      }
    }
    
    /**
      * @brief This function handles Prefetch fault, memory access fault.
      */
    void BusFault_Handler(void)
    {
      /* USER CODE BEGIN BusFault_IRQn 0 */
    
      /* USER CODE END BusFault_IRQn 0 */
      while (1)
      {
        /* USER CODE BEGIN W1_BusFault_IRQn 0 */
        /* USER CODE END W1_BusFault_IRQn 0 */
      }
    }
    
    /**
      * @brief This function handles Undefined instruction or illegal state.
      */
    void UsageFault_Handler(void)
    {
      /* USER CODE BEGIN UsageFault_IRQn 0 */
    
      /* USER CODE END UsageFault_IRQn 0 */
      while (1)
      {
        /* USER CODE BEGIN W1_UsageFault_IRQn 0 */
        /* USER CODE END W1_UsageFault_IRQn 0 */
      }
    }
    
    /**
      * @brief This function handles System service call via SWI instruction.
      */
    void SVC_Handler(void)
    {
      /* USER CODE BEGIN SVCall_IRQn 0 */
    
      /* USER CODE END SVCall_IRQn 0 */
      /* USER CODE BEGIN SVCall_IRQn 1 */
    
      /* USER CODE END SVCall_IRQn 1 */
    }
    
    /**
      * @brief This function handles Debug monitor.
      */
    void DebugMon_Handler(void)
    {
      /* USER CODE BEGIN DebugMonitor_IRQn 0 */
    
      /* USER CODE END DebugMonitor_IRQn 0 */
      /* USER CODE BEGIN DebugMonitor_IRQn 1 */
    
      /* USER CODE END DebugMonitor_IRQn 1 */
    }
    
    /**
      * @brief This function handles Pendable request for system service.
      */
    void PendSV_Handler(void)
    {
      /* USER CODE BEGIN PendSV_IRQn 0 */
    
      /* USER CODE END PendSV_IRQn 0 */
      /* USER CODE BEGIN PendSV_IRQn 1 */
    
      /* USER CODE END PendSV_IRQn 1 */
    }
    
    /**
      * @brief This function handles System tick timer.
      */
    void SysTick_Handler(void)
    {
      /* USER CODE BEGIN SysTick_IRQn 0 */
    
      /* USER CODE END SysTick_IRQn 0 */
      HAL_IncTick();
      /* USER CODE BEGIN SysTick_IRQn 1 */
    
      /* USER CODE END SysTick_IRQn 1 */
    }
    
    /******************************************************************************/
    /* STM32F1xx Peripheral Interrupt Handlers                                    */
    /* Add here the Interrupt Handlers for the used peripherals.                  */
    /* For the available peripheral interrupt handler names,                      */
    /* please refer to the startup file (startup_stm32f1xx.s).                    */
    /******************************************************************************/
    
    /**
      * @brief This function handles DMA1 channel4 global interrupt.
      */
    void DMA1_Channel4_IRQHandler(void)
    {
      /* USER CODE BEGIN DMA1_Channel4_IRQn 0 */
    
      /* USER CODE END DMA1_Channel4_IRQn 0 */
      HAL_DMA_IRQHandler(&hdma_usart1_tx);
      /* USER CODE BEGIN DMA1_Channel4_IRQn 1 */
    
      /* USER CODE END DMA1_Channel4_IRQn 1 */
    }
    
    /**
      * @brief This function handles DMA1 channel5 global interrupt.
      */
    void DMA1_Channel5_IRQHandler(void)
    {
      /* USER CODE BEGIN DMA1_Channel5_IRQn 0 */
    
      /* USER CODE END DMA1_Channel5_IRQn 0 */
      HAL_DMA_IRQHandler(&hdma_usart1_rx);
      /* USER CODE BEGIN DMA1_Channel5_IRQn 1 */
    
      /* USER CODE END DMA1_Channel5_IRQn 1 */
    }
    
    /**
      * @brief This function handles USART1 global interrupt.
      */
    
    
    void USART1_IRQHandler(void)
    {
      /* USER CODE BEGIN USART1_IRQn 0 */
      /* USER CODE END USART1_IRQn 0 */
      HAL_UART_IRQHandler(&huart1);
      /* USER CODE BEGIN USART1_IRQn 1 */
        
        //如果是串口1空闲触发的中断,IDLE标志位会置位SET
        if(__HAL_UART_GET_FLAG(&huart1,UART_FLAG_IDLE) == SET){  
            //__HAL_UART_CLEAR_FEFLAG(&huart1);  //清除帧错误标志位FE,该位会提醒当前字符是否存在帧错误    
            HAL_UART_DMAStop(&huart1);  //停止DMA从串口1中搬运数据
            uint8_t tempLen = __HAL_DMA_GET_COUNTER(&hdma_usart1_rx);  //获取DMA未搬运的数据大小    
            rcvLen = BUF_SIZE - tempLen;  //DMA当前搬运了的数据大小
            HAL_UART_Transmit(&huart1,rcvBuf,rcvLen,0xffff);        //将内存数据通过DNA发送到串口
            HAL_UART_Receive_DMA(&huart1,rcvBuf,BUF_SIZE);  //重新开始DMA搬运串口数据到内存
        }
        
      /* USER CODE END USART1_IRQn 1 */
    }
    
    /* USER CODE BEGIN 1 */
    
    /* USER CODE END 1 */
    

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