奇怪的DMA写FLASH数据异常

歹徒兄弟提问时间：2019-6-14 17:10 /

这几天都在调试DMA写入W25Q16，每次写1页256字节数据，现在遇到2个字节数据错位的问题，比如从1到256个字节依次存数值1,2,3...256，结果却成了3,4,5...256,1,2。我怀疑问题可能和DMA发送完成后的SPI善后处理有关，我的做法是DMA发送完成后进入DMA传输完成中断，中断中清除SPI的TXE中断请求后打开TXE中断，清除DMA中断请求关闭该DMA通道。    在SPI中断中判断：
1.如果是TXE中断：清除TXE中断请求，关闭TXE中断，清除RXNE中断请求后打开RXNE中断；
2.如果如果是RXNE中断：清除RXNE中断请求，关闭RXNE中断，置高片选信号退出中断处理。

代码如下：

/************************************************
函数名称： SPI_Configuration
功能： SPI配置
         SPI为主模式，时钟线平时为低，上升沿采集数据
         8位数据格式，软件控制片选，数据高位在前
参数：无
返回值：无
作者： ShiPeng
*************************************************/
void SPI3_Configuration(void)
{
SPI_InitTypeDef  SPI_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI3, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE);

GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable, ENABLE);//JTAG Disable SWDP Enable

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3  |  GPIO_Pin_4  | GPIO_Pin_5;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(GPIOB, &GPIO_InitStructure);
/* SPI: CS推挽输出 */
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_15;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
#ifdef SPI3_NSS_HARD
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
#else
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
#endif
  GPIO_Init(GPIOA, &GPIO_InitStructure);

/* SPI 初始化定义 */
  SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex; //SPI设置为双线双向全双工
  SPI_InitStructure.SPI_Mode = SPI_Mode_Master;                   //设置为主 SPI
  SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;                //SPI发送接收 8 位帧结构
  SPI_InitStructure.SPI_CPOL = SPI_CPOL_High;                      //时钟悬空高
  SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;                      //数据捕获于第二个时钟沿
  #ifdef SPI3_NSS_HARD
SPI_InitStructure.SPI_NSS = SPI_NSS_Hard;                         //硬件控制 NSS 信号
  #else
SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;                         //软件控制 NSS 信号
#endif
SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_2; //波特率预分频值为2
  SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;                //数据传输从 MSB 位开始
  SPI_InitStructure.SPI_CRCPolynomial = 7;                         //定义了用于 CRC值计算的多项式
  SPI_Init(SPI3, &SPI_InitStructure);
#ifdef SPI3_NSS_HARD
SPI_SSOutputCmd(SPI3, ENABLE);
SPI_Cmd(SPI3, DISABLE);
#else
SPI_Cmd(SPI3, ENABLE);
#endif

DMA_Config();
}
/************************************************
函数名称： DMA_Config
功能： DMA配置
参数：无
返回值：无
作者： ShiPeng
*************************************************/
void DMA_Config(void)
{
#define SPI3_DR_Addr ((u32)0x40003C0C)
DMA_InitTypeDef DMA_InitStructure;
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA2, ENABLE);
/*
DMA_DeInit(DMA2_Channel1);
DMA_InitStructure.DMA_PeripheralBaseAddr = SPI3_DR_Addr;
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)Rx_Buffer;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
DMA_InitStructure.DMA_BufferSize = 256;
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_VeryHigh;
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
DMA_Init(DMA2_Channel1, &DMA_InitStructure);

DMA_ITConfig(DMA2_Channel1, DMA_IT_TC, ENABLE);

// Disable SPI3 DMA RX request //
SPI_I2S_DMACmd(SPI3, SPI_I2S_DMAReq_Rx, ENABLE);
DMA_Cmd (DMA2_Channel1,DISABLE);
*/
DMA_DeInit(DMA2_Channel2);
DMA_InitStructure.DMA_PeripheralBaseAddr = SPI3_DR_Addr;
DMA_InitStructure.DMA_MemoryBaseAddr = (u32)Tx_Buffer;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
DMA_InitStructure.DMA_BufferSize = 256;
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_Medium;
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
DMA_Init(DMA2_Channel2, &DMA_InitStructure);

DMA_ITConfig(DMA2_Channel2, DMA_IT_TC, ENABLE);
DMA_ITConfig(DMA2_Channel2, DMA_IT_TE, ENABLE);

/* Disable SPI3 DMA TX request */
SPI_I2S_DMACmd(SPI3, SPI_I2S_DMAReq_Tx, ENABLE);
DMA_Cmd (DMA2_Channel2,DISABLE);
}

/************************************************
函数名称： SPI_WriteByte
功能： SPI写一字节数据
参数： TxData --- 发送的字节数据
返回值：读回来的字节数据
作者：
*************************************************/
uint8_t SPI3_WriteByte(uint8_t TxData)
{
  while((SPI3->SR & SPI_I2S_FLAG_TXE) == (uint16_t)RESET);
  SPI3->DR = TxData;

  while((SPI3->SR & SPI_I2S_FLAG_RXNE) == (uint16_t)RESET);
  return SPI3->DR;
}

/*******************************************************************************
* Function Name  : DMA2Channel2_IRQHandler
* Description : This function handles DMA Stream 1 interrupt request.
* Input       : None
* Output       : None
* Return       : None
*******************************************************************************/
void DMA2_Channel2_IRQHandler(void)
{
/* Test on DMA Channel1 Transfer Complete interrupt */
  if(DMA_GetITStatus(DMA2_IT_TC2))    //DMA2_IT_TC1:Transfer Completed
  {
/* Get Current Data Counter value after complete transfer */
//u16 buf16= DMA_GetCurrDataCounter(DMA2_Channel2);
DMA_Cmd (DMA2_Channel2,DISABLE);//SPI_I2S_DMACmd(SPI3, SPI_I2S_DMAReq_Tx, DISABLE);
//if (0==buf16){}
SPI_I2S_ClearITPendingBit(SPI3,SPI_I2S_IT_TXE);
SPI_I2S_ITConfig(SPI3, SPI_I2S_IT_TXE, ENABLE);
/* Clear DMA Channel1 Half Transfer, Transfer Complete and Global interrupt pending bits */
DMA_ClearITPendingBit(DMA2_IT_GL2);
  }
  if(DMA_GetITStatus(DMA2_IT_TE2))
{
SPI3_CS_DISABLE;
DMA_Config();
DMA_ClearITPendingBit(DMA2_IT_TE2);
}
}

void SPI3_IRQHandler(void)
{
if (SPI_I2S_GetITStatus(SPI3,SPI_I2S_IT_TXE))
{
SPI_I2S_ClearITPendingBit(SPI3,SPI_I2S_IT_TXE);
SPI_I2S_ITConfig(SPI3, SPI_I2S_IT_TXE, DISABLE);
SPI_I2S_ClearITPendingBit(SPI3,SPI_I2S_IT_RXNE);
SPI_I2S_ITConfig(SPI3, SPI_I2S_IT_RXNE, ENABLE);
}
if (SPI_I2S_GetITStatus(SPI3,SPI_I2S_IT_RXNE))
{
SPI3_CS_DISABLE;
SPI_I2S_ClearITPendingBit(SPI3,SPI_I2S_IT_RXNE);
SPI_I2S_ITConfig(SPI3, SPI_I2S_IT_RXNE, DISABLE);
}
}

void WriteFLASHPageUseDMA(uint32_t faddr)
{
SFLASH_WaitForNoBusy();
SFLASH_WriteEnable();
SPI3_CS_ENABLE;
SPI3_WriteByte(SFLASH_WRITE_PAGE);       //《页编程》指令
SPI3_WriteByte((uint8_t)(faddr>>16)); //发送24bit地址
SPI3_WriteByte((uint8_t)(faddr>>8));
SPI3_WriteByte(0);
DMA_Cmd (DMA2_Channel2,ENABLE);
}

如果放弃DMA采用轮询写入就不会有此问题：

void SFLASH_WritePage(uint8_t* pBuffer, uint32_t WriteAddr, uint16_t nByte)
{
  SFLASH_WriteEnable();                         //写使能

  SPI3_CS_ENABLE;                               //使能器件
  SPI3_WriteByte(SFLASH_WRITE_PAGE);             //《页编程》指令
  SPI3_WriteByte((uint8_t)((WriteAddr)>>16));    //发送24bit地址
  SPI3_WriteByte((uint8_t)((WriteAddr)>>8));
  SPI3_WriteByte((uint8_t)WriteAddr);

  while (nByte--)
  {
SPI3_WriteByte(*pBuffer);
pBuffer++;
  }

  SPI3_CS_DISABLE;
  SFLASH_WaitForNoBusy();                      //等待空闲（等待写入结束）
}

赞收藏评论2 发布时间：2019-6-14 17:10

2个回答

歹徒兄弟回答时间：2019-6-15 08:35:49

原因找到了，是因为在DMA_Config(void)函数中采用了循环模式"DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;",这样在DMA传输完成中断后会多发送两个字节的数据，虽然接下来关闭了DMA通道，但下次再启动DMA时不会从0地址开始发而是接着前面的2个字节往后发。解决办法就是采用DMA_Mode_Normal模式每次发送前初始化DMA传输计数寄存器DMA2_Channel2->CNDTR = 256 ;