DMA实验总结

一、RCC设置

没什么好写的之前USART的基本一样

     /****************************************************************************
    * Function Name : RCC_Configuration
    * Description : Sets System clock frequency to 72MHz and configure HCLK, PCLK2
    * and PCLK1 prescalers.
    * Input : None
    * Output : None
    * Return : None
    ****************************************************************************/
    void RCC_Configuration(void)
    {
        /* Deinitialize the RCC registers */
        RCC_DeInit();

        /* Enable the HSE */
        RCC_HSEConfig(RCC_HSE_ON);

        /* Wait till HSE is ready and if Time out is reached exit */
        HSEStartUpStatus = RCC_WaitForHSEStartUp();
        if(HSEStartUpStatus == SUCCESS)
        {
            /* Add here PLL ans system clock config */

            /* Enable The Prefetch Buffer */
            FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);

            /* Configure Tthe Latency cycle: Set 0 Latency cycles */
            FLASH_SetLatency(FLASH_Latency_2);

            /* Configure HCLK such as HCLK = SYSCLK */
            RCC_HCLKConfig(RCC_SYSCLK_Div1);

            /* PCLK2 = HCLK */
            RCC_PCLK2Config(RCC_HCLK_Div1);

            /* PCLK1 = HCLK/2 */
            RCC_PCLK1Config(RCC_HCLK_Div2);

            /* ADCCLK = PCLK2/4 */
            RCC_ADCCLKConfig(RCC_PCLK2_Div4);

            /* PLLCLK = 8MHz * 9 = 72MHz */
            RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_9);

            /* Enable PLL */
            RCC_PLLCmd(ENABLE);

            /* Wait till PLL is ready */
            while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET);

            /* Select PLL as system clock source */
            RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK); /* Wait till HSE is used as system clock source */
            while(RCC_GetSYSCLKSource() != 0x08)
            {

            }
        }
    }

二、GPIO设置

 

设置AP9,AP10为串口。

     /****************************************************************************
    * Function Name : GPIO_Configuration
    * Description :
    * Input : None
    * Output : None
    * Return : None
    ****************************************************************************/
    void GPIO_Configuration(void)
    {
        RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO | RCC_APB2Periph_USART1, ENABLE);

        GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
        GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
        GPIO_Init(GPIOA, &GPIO_InitStructure);

        GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
        GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
        GPIO_Init(GPIOA, &GPIO_InitStructure);

        GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;
        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
        GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
        GPIO_Init(GPIOB, &GPIO_InitStructure);

    }

三、USART设置

 

     /*******************************************************************************
    * Function Name : USART_Configure
    * Description : Configures the USART
    * Input : None
    * Output : None
    * Return : None
    *******************************************************************************/
    void USART_Configuration(void)
    {
        USART_InitStructure.USART_BaudRate = ;                            //设置波特率
        USART_InitStructure.USART_WordLength = USART_WordLength_8b;             //设置为8位
        USART_InitStructure.USART_StopBits = USART_StopBits_1;                  //停止为1位
        USART_InitStructure.USART_Parity = USART_Parity_No;                     //没有校验位
        USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;          //没有流控
        USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;         //设置RX和TX模式
        USART_Init(USART1, &USART_InitStructure);                               //初始化结构体
        USART_Cmd(USART1, ENABLE);                                              //开启串口
    }

四、DMA设置

 

     /*******************************************************************************
    * Function Name : DMA_Configure
    * Description : Configures the DMA
    * Input : None
    * Output : None
    * Return : None
    *******************************************************************************/
    void DMA_Configuration(void)
    {
        DMA_InitTypeDef DMA_InitStructure;                                         //定义DMA结构体

        RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);                         //开启DMA的RCC

        DMA_InitStructure.DMA_PeripheralBaseAddr = APB2PERIPH_BASE + 0X3804;       //设置DMA外设基地址：串口1的地址+串口1的数据寄存器偏移量

        DMA_InitStructure.DMA_MemoryBaseAddr = (u32)SendBuff;                      //要发送的内容地址

        DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;                         //设置外设作为数据传输的目的地

        DMA_InitStructure.DMA_BufferSize = SENDBUFF_SIZE;                          //指定DMA缓存大小

        DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;           //设置外设地址寄存器不递增

        DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;                    //内存地址寄存器递增

        DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;    //数据宽度为8位

        DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;            //数据宽度为8位

        DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;                              //工作在正常缓存模式

        DMA_InitStructure.DMA_Priority = DMA_Priority_Medium;                      //设置DMA为中优先级

        DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;                               //不设置为内存到内存传输

        DMA_Init(DMA1_Channel4, &DMA_InitStructure);                               //初始化DMA结构体

        DMA_Cmd(DMA1_Channel4, ENABLE);                                            //开启DMA
        DMA_ITConfig(DMA1_Channel4, DMA_IT_TC, ENABLE);                            //使能DMA1_Channel4作为中断通道，传输完成后中断屏蔽，使能
    }

五、设置中断

     /****************************************************************************
    * Function Name : NVIC_Configuration
    * Description : Configures Vector Table base location.
    * Input : None
    * Output : None
    * Return : None
    ****************************************************************************/
    void NVIC_Configuration(void)
    {
        NVIC_InitTypeDef NVIC_InitStructure;

    #ifdef VET_TAB_RAM
        /* Set the Vector Table base location at 0x2000 0000 */
        NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x0);
    #else
        /* Set the Vector Table base location at 0x8000 0000 */
        NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0);
    #endif

        NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);                           //设置为组1

        NVIC_InitStructure.NVIC_IRQChannel = DMA1_Channel4_IRQn;                  //设置DMA1_Channel4为中断源
        NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = ;                 //优先级1
        NVIC_InitStructure.NVIC_IRQChannelSubPriority = ;                        //子优先级1
        NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;                           //使能
        NVIC_Init(&NVIC_InitStructure);                                           //初始化
    }

在stm32f10x_it.c中加入：

 

     void DMA1_Channel4_IRQHandler(void)
    {
        if(DMA_GetFlagStatus(DMA1_FLAG_TC4) == SET)          //如果中断源是设置了
        {
            DMA_ClearFlag(DMA1_FLAG_TC4);                    //清除中断
        }
    }

六、main函数

 

     /****************************************************************************
    * Function Name : main
    * Description : Main program.
    * Input : None
    * Output : None
    * Return : None
    ****************************************************************************/
    int main(void)
    {
        RCC_Configuration();

        NVIC_Configuration();

        GPIO_Configuration();

        USART_Configuration();

        DMA_Configuration();

        while()
        {
            GPIO_WriteBit(GPIOB, GPIO_Pin_8, (BitAction)( - GPIO_ReadOutputDataBit(GPIOB, GPIO_Pin_8)));
            fPutString("Hello World!", );
            Delay(0xffffff);
        }
    }

    /****************************************************************************
    * Function Name : fPutString
    * Description : Send a string.
    * Input : None
    * Output : None
    * Return : None
    ****************************************************************************/
    void fPutString(u8 *buf, u8 len)
    {
        u8 i;
        for(i=;i<len;i++)
        {
            fPutChar(*buf++);
        }
    }

    /****************************************************************************
    * Function Name : fPutChar
    * Description : Send a byte
    * Input : None
    * Output : None
    * Return : None
    ****************************************************************************/
    u8 fPutChar(u8 ch)
    {
        USART_SendData(USART1, (u8) ch);
        while(USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET)
        {

        }
        return ch;
    }

• /*******************************************************************************
• * Function Name : USART_Configure
• * Description : Configures the USART
• * Input : None
• * Output : None
• * Return : None
• *******************************************************************************/
• void USART_Configuration(void)
• {
• USART_InitStructure.USART_BaudRate = 115200;
• USART_InitStructure.USART_WordLength = USART_WordLength_8b;
• USART_InitStructure.USART_StopBits = USART_StopBits_1;
• USART_InitStructure.USART_Parity = USART_Parity_No;
• USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
• USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
• USART_Init(USART1, &USART_InitStructure);
• USART_Cmd(USART1, ENABLE);
• }