[STM32F7] STM32F7对串口数据进行硬件CRC16，DMA + CPU两种方式

/* Private typedef -----------------------------------------------------------*/

/* Private define ------------------------------------------------------------*/

/* aDataBuffer is 32 bit long*/

#define BUFFER_SIZE 7



/* The user defined polynomial*/

#define CRC_POLYNOMIAL_8B 0xA001 



/* Private macro -------------------------------------------------------------*/

/* Private variables ---------------------------------------------------------*/

/* CRC handler declaration */

CRC_HandleTypeDef   CrcHandle;

DMA_HandleTypeDef DmaHandle;



/* Used for storing CRC Value */

__IO uint32_t uwCRCValue = 0;

__IO uint32_t uwCRCValue1 = 0;



/* Buffer containing the data on which the CRC will be calculated 

  (one-word buffer in this example) */

static const uint32_t aDataBuffer[] = {0x02006D1D,0x0000007C};

static const uint8_t bDataBuffer[] = {0x1D,0x6D,0x00,0x02,0x7C,0x00,0x00};



int main(void)

{

  /* Enable the CPU Cache */

  CPU_CACHE_Enable();

  

  /* STM32F7xx HAL library initialization:

       - Configure the Flash prefetch

       - Systick timer is configured by default as source of time base, but user 

         can eventually implement his proper time base source (a general purpose 

         timer for example or other time source), keeping in mind that Time base 

         duration should be kept 1ms since PPP_TIMEOUT_VALUEs are defined and 

         handled in milliseconds basis.

       - Set NVIC Group Priority to 4

       - Low Level Initialization

     */

  HAL_Init();

  

  /* Configure the system clock to 216 MHz */

  SystemClock_Config();



  /* Configure LED1 and LED3 */

  BSP_LED_Init(LED1);

  BSP_LED_Init(LED3);



  /*##-1- Configure the CRC peripheral #######################################*/

  CrcHandle.Instance = CRC;



  /* The default polynomial is not used. It is required to defined it in CrcHandle.Init.GeneratingPolynomial*/  

  CrcHandle.Init.DefaultPolynomialUse    = DEFAULT_POLYNOMIAL_DISABLE;

  

  /* Set the value of the polynomial */

  CrcHandle.Init.GeneratingPolynomial    = 0x8005;

  

  /* The user-defined generating polynomial generates a

     8-bit long CRC */

  CrcHandle.Init.CRCLength               = CRC_POLYLENGTH_16B;



  /* The default init value is used */

  CrcHandle.Init.DefaultInitValueUse     = DEFAULT_INIT_VALUE_DISABLE;



  /* The input data are not inverted */

  CrcHandle.Init.InputDataInversionMode  = CRC_INPUTDATA_INVERSION_BYTE;//CRC_INPUTDATA_INVERSION_NONE;



  /* The output data are not inverted */

  CrcHandle.Init.OutputDataInversionMode = CRC_OUTPUTDATA_INVERSION_ENABLE;//CRC_OUTPUTDATA_INVERSION_DISABLE;



  /* The input data are 32-bit long */

  CrcHandle.InputDataFormat              = CRC_INPUTDATA_FORMAT_BYTES;

  

  CrcHandle.Init.InitValue = 0x0000FFFF;



  if (HAL_CRC_Init(&CrcHandle) != HAL_OK)

  {

    /* Initialization Error */

    Error_Handler();

  }

  

  

  __HAL_RCC_DMA2_CLK_ENABLE();

  DmaHandle.Init.Channel = DMA_CHANNEL_0;

  DmaHandle.Init.Direction = DMA_MEMORY_TO_MEMORY;

  DmaHandle.Init.FIFOMode = DMA_FIFOMODE_DISABLE;

  DmaHandle.Init.MemBurst = DMA_MBURST_SINGLE;

  DmaHandle.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;

  DmaHandle.Init.MemInc = DMA_MINC_DISABLE;

  DmaHandle.Init.Mode = DMA_NORMAL;

  DmaHandle.Init.PeriphBurst = DMA_PBURST_SINGLE;

  DmaHandle.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;

  DmaHandle.Init.PeriphInc = DMA_PINC_ENABLE;

  DmaHandle.Init.Priority = DMA_PRIORITY_VERY_HIGH ;

  DmaHandle.Instance = DMA2_Stream0;

  

  if(HAL_DMA_Init(&DmaHandle) != HAL_OK)

  {

          Error_Handler();

  }

  __HAL_CRC_DR_RESET(&CrcHandle);

  

  if( HAL_DMA_Start(&DmaHandle,(uint32_t)bDataBuffer, (uint32_t)&CRC->DR, BUFFER_SIZE ) != HAL_OK)

  {

          Error_Handler();

  }

  while(__HAL_DMA_GET_FLAG(&DmaHandle,DMA_FLAG_TCIF0_4) == 0);

  __HAL_DMA_CLEAR_FLAG(&DmaHandle,DMA_FLAG_TCIF0_4);

  uwCRCValue1 = CRC->DR;



  /*##-2- Compute the CRC of "aDataBuffer" ###################################*/

  uwCRCValue = HAL_CRC_Calculate(&CrcHandle, (uint32_t *)aDataBuffer, BUFFER_SIZE);

  

  /*##-3- Compare the CRC value to the Expected one ##########################*/

  if (uwCRCValue != uwExpectedCRCValue)

  {

    /* Wrong CRC value: Turn LED3 on */

    Error_Handler();

  }

  else

  {

    /* Right CRC value: Turn LED1 on */

    BSP_LED_On(LED1);

  }



  /* Infinite loop */

  while (1)

  {

  }

}