基于stm32的DMA串口程序

以下是基于STM32的DMA串口程序的示例代码：

#include "stm32f10x.h"

#define USART1_DR_Base 0x40013804    // USART1数据寄存器地址

void USART1_Config(void);
void DMA_Configuration(void);
void RCC_Configuration(void);
void GPIO_Configuration(void);

uint8_t TxBuffer[] = "Hello, world! This is a test message.\r\n";
uint8_t RxBuffer[64];

int main(void)
{
    RCC_Configuration();
    GPIO_Configuration();
    USART1_Config();
    DMA_Configuration();

    while (1)
    {
        // 等待DMA发送完成
        while (DMA_GetFlagStatus(DMA1_FLAG_TC4) == RESET);

        // 清除DMA标志位
        DMA_ClearFlag(DMA1_FLAG_TC4);

        // 打开DMA传输
        DMA_Cmd(DMA1_Channel4, ENABLE);
    }
}

void RCC_Configuration(void)
{
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_USART1, ENABLE);
    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
}

void GPIO_Configuration(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;

    // USART1_TX
    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);

    // USART1_RX
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
}

void USART1_Config(void)
{
    USART_InitTypeDef USART_InitStructure;

    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_Tx | USART_Mode_Rx;
    USART_Init(USART1, &USART_InitStructure);
    USART_Cmd(USART1, ENABLE);
}

void DMA_Configuration(void)
{
    DMA_InitTypeDef DMA_InitStructure;

    // 配置DMA1_Channel4，将TxBuffer中的数据发送到USART1
    DMA_DeInit(DMA1_Channel4);
    DMA_InitStructure.DMA_PeripheralBaseAddr = USART1_DR_Base;
    DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)TxBuffer;
    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
    DMA_InitStructure.DMA_BufferSize = sizeof(TxBuffer) - 1;
    DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
    DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
    DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
    DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
    DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
    DMA_InitStructure.DMA_Priority = DMA_Priority_High;
    DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
    DMA_Init(DMA1_Channel4, &DMA_InitStructure);

    // 配置DMA1_Channel5，将USART1接收到的数据写入RxBuffer
    DMA_DeInit(DMA1_Channel5);
    DMA_InitStructure.DMA_PeripheralBaseAddr = USART1_DR_Base;
    DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)RxBuffer;
    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
    DMA_InitStructure.DMA_BufferSize = sizeof(RxBuffer);
    DMA_Init(DMA1_Channel5, &DMA_InitStructure);

    // 配置USART1的DMA接收
    USART_DMACmd(USART1, USART_DMAReq_Rx, ENABLE);
    DMA_Cmd(DMA1_Channel5, ENABLE);
}

这个程序使用了DMA来进行串口数据的发送和接收。在主循环中，程序等待DMA发送完成，然后再打开DMA传输。DMA的配置可以通过STM32的库函数来完成，需要注意的是，发送和接收分别使用了不同的DMA通道。