STM32空閑中斷+DMA解決接收不定長資料問題

http://blog.csdn.net/shu_8708/article/details/73480939

序列槽的中斷類型:

[cpp]  view plain  copy

1. #define USART_IT_PE                          ((uint16_t)0x0028)  
2. #define USART_IT_TXE                         ((uint16_t)0x0727)  
3. #define USART_IT_TC                          ((uint16_t)0x0626)  
4. #define USART_IT_RXNE                        ((uint16_t)0x0525)  
5. #define USART_IT_IDLE                        ((uint16_t)0x0424)  
6. #define USART_IT_LBD                         ((uint16_t)0x0846)  
7. #define USART_IT_CTS                         ((uint16_t)0x096A)  
8. #define USART_IT_ERR                         ((uint16_t)0x0060)  
9. #define USART_IT_ORE                         ((uint16_t)0x0360)  
10. #define USART_IT_NE                          ((uint16_t)0x0260)  
11. #define USART_IT_FE                          ((uint16_t)0x0160)  

USART_IT_PE 奇偶錯誤中斷

USART_IT_TXE發送中斷

USART_IT_TC 傳輸完成中斷

USART_IT_RXNE 接收中斷

USART_IT_IDLE 空閑總線中斷

USART_IT_LBD LIN中斷檢測中斷

USART_IT_CTS CTS中斷

USART_IT_ERR 錯誤中斷

該程式中用到的就是序列槽的空閑中斷:當總線是一個位元組周期内沒有收到資料時觸發

序列槽的配置如下:

[cpp]  view plain  copy

1. void uart_init(u32 bound){  
2.         GPIO_InitTypeDef GPIO_InitStructure;  
3.     USART_InitTypeDef USART_InitStructure;  
4.     RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOA, ENABLE);   
5.     NVIC_InitTypeDef NVIC_InitStructure;  
6.      //IO口相關配置  
7.     USART_DeInit(USART1);    
8.         GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;//IO口速率  
9.         GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;   
10.         GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  
11.         GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;  
12.         GPIO_Init(GPIOA, &GPIO_InitStructure);   
13.         GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;  
14.         GPIO_Init(GPIOA, &GPIO_InitStructure);    
15.         //序列槽中斷配置  
16.     NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;        
17.         NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;  
18.     NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;  
19.     NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;           
20.     NVIC_Init(&NVIC_InitStructure);   
21.     USART_InitStructure.USART_Parity = USART_Parity_No;//沒有奇偶校驗位  
22.     USART_InitStructure.USART_BaudRate = bound;       //波特率設定  
23.     USART_InitStructure.USART_WordLength = USART_WordLength_8b;//8位資料位  
24.     USART_InitStructure.USART_StopBits = USART_StopBits_1;//1位停止位  
25.     USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//無硬體資料流配置  
26.     USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;//序列槽收發模式  
27.         USART_Init(USART1, &USART_InitStructure);   
28.         USART_ITConfig(USART1, USART_IT_IDLE, ENABLE);  
29.         USART_Cmd(USART1, ENABLE);    
30. }    

序列槽中斷配置: void USART1_IRQHandler(void)                  

{

      if(USART_GetITStatus(USART1, USART_IT_IDLE) != RESET) 

{

       DMA_Cmd(DMA1_Channel5,DISABLE);

       recok=1;

       lenth=USART1->DR;//軟體清空空閑中斷标志位

       lenth=USART1->SR;

       lenth=32-DMA_GetCurrDataCounter(DMA1_Channel5);//擷取目前接收的資料量 

       USART_RX_BUF[lenth]=0;//在buff最後加入空字元

       DMA1_Channel5->CNDTR=32;//重新設定傳輸量為32 

       DMA_Cmd(DMA1_Channel5,ENABLE);

    } 

} 

DMA配置:

void MYDMA_Config(DMA_Channel_TypeDef* DMA_CHx,u32 cpar,u32 cmar,u16 cndtr)

{

  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);//使能DMA時鐘

      DMA_DeInit(DMA_CHx);

      DMA1_MEM_LEN=cndtr;

      DMA_InitStructure.DMA_PeripheralBaseAddr = cpar;//外設位址

      DMA_InitStructure.DMA_MemoryBaseAddr = cmar; //記憶體位址

      DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC; //傳輸方向外設到記憶體

      DMA_InitStructure.DMA_BufferSize = cndtr;  //傳輸量

      DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;//外設位址不自增  

      DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable; //記憶體位址自增

      DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte; 

      DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte; 

      DMA_InitStructure.DMA_Mode = DMA_Mode_Normal; //普通模式

      DMA_InitStructure.DMA_Priority = DMA_Priority_High;//高優先級

      DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;

      DMA_Init(DMA_CHx, &DMA_InitStructure);  

} 

主函數中需要進行的配置:

[cpp]  view plain  copy

1. MYDMA_Config(DMA1_Channel5,(u32)&USART1->DR,(u32)USART_RX_BUF,32);//傳輸方向設定為USART1->DR到USART_RX_BUF 傳輸大小為32位元組  
2. USART_DMACmd(USART1,USART_DMAReq_Rx,ENABLE);//允許DMA請求  
3. DMA_Cmd(DMA1_Channel5,ENABLE);  

當标志為recok位1時表示接受完成  在主函數中等待recok位1就可以了