stm32 uart dma fifo 收发 标准库例程

以下是基于STM32标准库的UART DMA收发FIFO例程：

#include "stm32f10x.h"
#include <stdio.h>

#define BUFFER_SIZE 64

uint8_t Rx_Buffer[BUFFER_SIZE];
uint8_t Tx_Buffer[BUFFER_SIZE];
uint8_t Rx_Idx = 0;
uint8_t Tx_Idx = 0;

void USART_Config(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    USART_InitTypeDef USART_InitStructure;
    DMA_InitTypeDef DMA_InitStructure;
    
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_USART1, ENABLE);
    RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, 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);
    
    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);
    
    DMA_DeInit(DMA1_Channel5);
    DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&USART1->DR;
    DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)Rx_Buffer;
    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
    DMA_InitStructure.DMA_BufferSize = BUFFER_SIZE;
    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_Circular;
    DMA_InitStructure.DMA_Priority = DMA_Priority_High;
    DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
    DMA_Init(DMA1_Channel5, &DMA_InitStructure);
    
    DMA_DeInit(DMA1_Channel4);
    DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&USART1->DR;
    DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)Tx_Buffer;
    DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
    DMA_InitStructure.DMA_BufferSize = BUFFER_SIZE;
    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);
    
    USART_DMACmd(USART1, USART_DMAReq_Rx, ENABLE);
    USART_DMACmd(USART1, USART_DMAReq_Tx, ENABLE);
    
    DMA_Cmd(DMA1_Channel5, ENABLE);
    DMA_Cmd(DMA1_Channel4, DISABLE);
    
    USART_Cmd(USART1, ENABLE);
}

uint8_t USART_GetChar(void)
{
    uint8_t ch = Rx_Buffer[Rx_Idx++];
    Rx_Idx %= BUFFER_SIZE;
    return ch;
}

void USART_PutChar(uint8_t ch)
{
    Tx_Buffer[Tx_Idx++] = ch;
    Tx_Idx %= BUFFER_SIZE;
    DMA_Cmd(DMA1_Channel4, ENABLE);
}

void DMA1_Channel4_IRQHandler(void)
{
    if (DMA_GetITStatus(DMA1_IT_TC4))
    {
        DMA_Cmd(DMA1_Channel4, DISABLE);
        DMA_ClearITPendingBit(DMA1_IT_TC4);
    }
}

int main(void)
{
    USART_Config();
    
    while (1)
    {
        if (Rx_Idx != 0)
        {
            uint8_t ch = USART_GetChar();
            USART_PutChar(ch + 1);
        }
    }
}

这个例程使用了STM32的UART1作为串口通信的接口，并且使用了DMA来进行数据的传输。在这个例程中，定义了一个接收缓冲区`Rx_Buffer`和一个发送缓冲区`Tx_Buffer`，分别用于存储接收到的数据和要发送的数据。收到的数据会存储到接收缓冲区中，并且会在下一次轮询时被处理，处理完后会将发送数据存储到发送缓冲区中，并启动DMA进行发送。