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关于stm32f407 I2s DMA主发送的问题

发布于 2013-06-28 15:29:44 浏览：3069 订阅该版

最近用stm32f407做一个sd卡mp3解码后，音频传输的项目，声卡芯片用的VM8978，采取的是SPI3的i2s，用的DMA是DMA1的stream5通道0.用的是主发送模式,程序代码是用的realtouch修改过来的代码。
在dma中断中我用一个led反转看是否进入中断，结果是，中断进入，但i2s 引脚为何没有输出，按道理说应该是有波形输出的啊 BCLk脚怎么一直是低电平了？

程序如下：
```c
DMA_InitTypeDef DMA_InitStructure;
u32 AudioTotalSize = 0xffff; 
u32 AudioRemSize = 0; 
u16 *CurrentPos;

extern void AUDIO_TransferComplete(u32 pBuffer, uint32_t Size);
void AUDIO_Init(u32 AudioFreq)
{
        Audio_I2S_Init(AudioFreq);
        I2S_GPIO_Init();
        Audio_DMA_Init();
}
void I2s_GPIO_DEinit(void)
{
          GPIO_InitTypeDef GPIO_InitStructure;
          RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
          RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;

/* I2S3S_WS */
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
    /* I2S3_CK, I2S3_SD, I2S3ext_SD */
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3 | GPIO_Pin_4 | GPIO_Pin_5;
    GPIO_Init(GPIOB, &GPIO_InitStructure);

}
void I2S_GPIO_Init(void)
{
          GPIO_InitTypeDef GPIO_InitStructure;
                I2s_GPIO_DEinit();
          RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
          RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;

/* Connect pins to I2S peripheral  */
    GPIO_PinAFConfig(GPIOA, GPIO_PinSource15, GPIO_AF_SPI3);
    GPIO_PinAFConfig(GPIOB, GPIO_PinSource3, GPIO_AF_SPI3);
    GPIO_PinAFConfig(GPIOB, GPIO_PinSource4, GPIO_AF_I2S3ext);
    GPIO_PinAFConfig(GPIOB, GPIO_PinSource5, GPIO_AF_SPI3);

}

void Audio_I2S_Init(uint32_t AudioFreq)
{
          I2S_InitTypeDef I2S_InitStructure;
                SPI_I2S_DeInit(SPI3);
          RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI3, ENABLE);
          SPI_I2S_DeInit(SPI3);
          I2S_InitStructure.I2S_AudioFreq = AudioFreq;
          I2S_InitStructure.I2S_Standard = I2S_Standard_Phillips;
          I2S_InitStructure.I2S_DataFormat = I2S_DataFormat_16b;
          I2S_InitStructure.I2S_CPOL = I2S_CPOL_Low;
          I2S_InitStructure.I2S_Mode = I2S_Mode_MasterTx;
          I2S_InitStructure.I2S_MCLKOutput = I2S_MCLKOutput_Disable; 
          I2S_Init(SPI3, &I2S_InitStructure);
}

//DMA传送配置
void Audio_DMA_Init(void)  
{ 
          NVIC_InitTypeDef NVIC_InitStructure;
          RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA1, ENABLE); 
          DMA_Cmd(DMA1_Stream5, DISABLE);
          DMA_DeInit(DMA1_Stream5);
          DMA_InitStructure.DMA_Channel = DMA_Channel_0;  
          DMA_InitStructure.DMA_PeripheralBaseAddr = 0x4000380C;
          DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)0;//该项将在播放函数中进行配置
          DMA_InitStructure.DMA_DIR = DMA_DIR_MemoryToPeripheral;
          DMA_InitStructure.DMA_BufferSize = (uint32_t)0xFFFE;//该项将在播放函数中进行配置      
          DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
          DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
          DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
          DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord; 
          DMA_InitStructure.DMA_Mode = DMA_Mode_Normal; 
          DMA_InitStructure.DMA_Priority = DMA_Priority_High;
          DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Disable;         
          DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_1QuarterFull;
          DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
          DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;  
          DMA_Init(DMA1_Stream5, &DMA_InitStructure);  
          DMA_ITConfig(DMA1_Stream5, DMA_IT_TC, ENABLE);//使能所选DMA的中断
          //I2S DMA中断通道配置
          NVIC_InitStructure.NVIC_IRQChannel = DMA1_Stream5_IRQn;
          NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;//抢占优先级(0 最高)
          NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;//子优先级(0 最高)
          NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
          NVIC_Init(&NVIC_InitStructure);   
          SPI_I2S_DMACmd(SPI3, SPI_I2S_DMAReq_Tx, ENABLE);//中断请求使能  
}

//开始从特定大小（Size）的缓冲区（pBuffer）中播放音频流
uint32_t AUDIO_Play(u16* pBuffer, u32 Size)
{
          AudioTotalSize=Size; 
          Audio_MAL_Play((u32)pBuffer,(u32)(DMA_MAX(Size/4)));//更新媒体层数据并播放
          AudioRemSize=(Size/2)-DMA_MAX(AudioTotalSize);//更新剩余数据量
          CurrentPos=pBuffer+DMA_MAX(AudioTotalSize);//更新当新数据指针 
          return 0;
}

//开始播放媒体中的音频流
void Audio_MAL_Play(u32 Addr, u32 Size)
{         
          DMA_InitStructure.DMA_Memory0BaseAddr=(uint32_t)Addr;//配置缓冲区地址和大小
          DMA_InitStructure.DMA_BufferSize=(uint32_t)Size/2;
          DMA_Init(DMA1_Stream5,&DMA_InitStructure);
          DMA_Cmd(DMA1_Stream5,ENABLE);//I2S DMA使能   
          if ((SPI3->I2SCFGR & I2S_ENABLE_MASK)==0)I2S_Cmd(SPI3,ENABLE);//若I2S接口未使能，则使能
}

//I2S中断处理
void SPI3_IRQHandler(void)
{
          if (SPI_I2S_GetFlagStatus(SPI3,SPI_I2S_FLAG_TXE)!=RESET)
          {             
            SPI_I2S_SendData(SPI3, 0);//发送空字节到I2S 
                        SPI_I2S_ClearFlag(SPI3,SPI_I2S_FLAG_TXE);
          }
}

//DMA中断处理函数
void DMA1_Stream5_IRQHandler(void)
{    
          //传送完成中断
          if (DMA_GetFlagStatus(DMA1_Stream5, DMA_FLAG_TCIF5)!=RESET)
          {  
                        if (AudioRemSize>0)//查看是否到达文件尾
            {   
                        printf("DMA1
");
                      while (DMA_GetCmdStatus(DMA1_Stream5) != DISABLE) IWDG_ReloadCounter();//等待DMA disabled     
                      DMA_ClearFlag(DMA1_Stream5, DMA_FLAG_TCIF5);//清传送完成中断标志           
                      DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t) CurrentPos;//重新配置缓冲区地址和大小
                      DMA_InitStructure.DMA_BufferSize = (uint32_t) (DMA_MAX(AudioRemSize));            
                      DMA_Init(DMA1_Stream5, &DMA_InitStructure);
                      DMA_Cmd(DMA1_Stream5, ENABLE);    
                      CurrentPos += DMA_MAX(AudioRemSize);//更新数据指针        
                      AudioRemSize -= DMA_MAX(AudioRemSize);//更新剩余数据   
                      DMA_Cmd(DMA1_Stream5, ENABLE); 
            }
            else//已到达文件尾
            {
                     DMA_Cmd(DMA1_Stream5, DISABLE);   
                      DMA_ClearFlag(DMA1_Stream5, DMA_FLAG_TCIF5);       
                      AUDIO_TransferComplete((uint32_t)CurrentPos, 0);       
                        STM_EVAL_LEDToggle(2);                                    //led反转 ，显示状态
//                         printf("DMA2
");
            }
        //                                        printf("DMA3
");

}
}
```