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

/****************************************************************************
* 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);

}

设置AP9,AP10为串口。

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 = 115200;                            //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 = 1;                 //优先级1
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;                        //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(1)
    {
        GPIO_WriteBit(GPIOB, GPIO_Pin_8, (BitAction)(1 - GPIO_ReadOutputDataBit(GPIOB, GPIO_Pin_8)));
        fPutString("Hello World!", 13);
        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=0;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);

}