1 void USART3_Configuration(void) //串口3配置---S

  2 {

  3 DMA_InitTypeDef DMA_InitStructure;

  4 USART_InitTypeDef USART_InitStructure;

  5 GPIO_InitTypeDef GPIO_InitStructure;

  6 NVIC_InitTypeDef NVIC_InitStructure;

  7 RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3, ENABLE);

  8 RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1|RCC_AHBPeriph_DMA2, ENABLE);

  9 //USART1

 10 //TX

 11 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;

 12 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;

 13 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

 14 GPIO_Init(GPIOB, &GPIO_InitStructure);

 15 //RX

 16 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;

 17 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD;

 18 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

 19 GPIO_Init(GPIOB, &GPIO_InitStructure);

 20

 21 DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&( USART3->DR);

 22 DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)_code_rece;

 23 DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;

 24 DMA_InitStructure.DMA_BufferSize = 4000;

 25 DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;

 26 DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;

 27 DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte; //HalfWord

 28 DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;

 29 DMA_InitStructure.DMA_Mode = DMA_Mode_Circular ; // DMA_Mode_Normal

 30 DMA_InitStructure.DMA_Priority = DMA_Priority_Medium; //DMA_Priority_Low DMA_Priority_Medium DMA_Priority_High

 31 DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;

 32 DMA_Init(DMA1_Channel3, &DMA_InitStructure);

 33

 34 DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&( USART3->DR);

 35 DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)_send_data;

 36 DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;

 37 DMA_InitStructure.DMA_BufferSize = 14;

 38 DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;

 39 DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;

 40 DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte; //HalfWord

 41 DMA_InitStructure.DMA_MemoryDataSize = DMA_PeripheralDataSize_Byte;

 42 DMA_InitStructure.DMA_Mode = DMA_Mode_Normal ; // DMA_Mode_Normal

 43 DMA_InitStructure.DMA_Priority = DMA_Priority_Medium; //DMA_Priority_Low DMA_Priority_Medium DMA_Priority_High

 44 DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;

 45 DMA_Init(DMA1_Channel2, &DMA_InitStructure);

 46

 47 USART_OverSampling8Cmd(USART3, ENABLE);

 48 USART_InitStructure.USART_BaudRate = 460800;

 49 USART_InitStructure.USART_WordLength = USART_WordLength_8b;

 50 USART_InitStructure.USART_StopBits = USART_StopBits_1;

 51 USART_InitStructure.USART_Parity = USART_Parity_No;

 52 USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;

 53 USART_InitStructure.USART_Mode = USART_Mode_Rx|USART_Mode_Tx;

 54 USART_Init(USART3, &USART_InitStructure);

 55

 56 //NVIC 设置，使能中断

 57 NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1); //选择中断分组1

 58

 59 NVIC_InitStructure.NVIC_IRQChannel = USART3_IRQn; //选择串口3中断

 60 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; //抢占式中断优先级设置为1

 61 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; //响应式中断优先级设置为1

 62 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //使能中断

 63 NVIC_Init(&NVIC_InitStructure);

 64 USART_ITConfig(USART3, USART_IT_IDLE, ENABLE);//开启中断

 65

 66 USART_DMACmd(USART3,USART_DMAReq_Rx,ENABLE);

 67 USART_DMACmd(USART3,USART_DMAReq_Tx,ENABLE);

 68 DMA_Cmd(DMA1_Channel3, ENABLE);

 69 USART_Cmd(USART3, ENABLE);

 70 USART3->SR;

 71 USART3->DR;

 72 }

 73

 74 DmaSendDataProc( DMA1_Channel2, 14 );

 75 //开启一次DMA传输

 76 void DmaSendDataProc(DMA_Channel_TypeDef *DMA_Streamx,u16 ndtr)

 77 {

 78

 79 DMA_Cmd(DMA_Streamx, DISABLE); //关闭DMA传输

 80

 81 DMA_SetCurrDataCounter(DMA_Streamx,ndtr); //数据传输量

 82

 83 DMA_Cmd(DMA_Streamx, ENABLE); //开启DMA传输

 84

 85 }

 86 void USART3_IRQHandler(void)    //客户端传来数据

 87 {

 88 if(USART_GetFlagStatus(USART3, USART_FLAG_IDLE)==SET) //RXNE一个字节接收完成标志位，

 89 {

 90 DMA_Cmd(DMA1_Channel3, DISABLE); //关闭DMA输出

 91

 92 usart2_num = 2000 - DMA1_Channel3 ->CNDTR; //获取读到的字节数

 93 //处理数据

 94 DMA1_Channel3->CNDTR = 2000; //重新填充

 95 DMA_Cmd(DMA1_Channel3, ENABLE); //开启DMA传输

 96 }

 97

 98 USART_ClearITPendingBit(USART3, USART_IT_IDLE); //清除接收中断标志位

 99 USART3->SR;

100 USART3->DR;

101

102 }