CRC Private Functions

Functions
static uint32_t	CRC_Handle_8 (CRC_HandleTypeDef *hcrc, uint8_t pBuffer[], uint32_t BufferLength)
	Enter 8-bit input data to the CRC calculator. Specific data handling to optimize processing time. More...
static uint32_t	CRC_Handle_16 (CRC_HandleTypeDef *hcrc, uint16_t pBuffer[], uint32_t BufferLength)
	Enter 16-bit input data to the CRC calculator. Specific data handling to optimize processing time. More...

Detailed Description

Function Documentation

CRC_Handle_16()

static uint32_t CRC_Handle_16 ( CRC_HandleTypeDef *  hcrc, uint16_t  pBuffer[], uint32_t  BufferLength  )

static

Enter 16-bit input data to the CRC calculator. Specific data handling to optimize processing time.

Parameters

hcrc	CRC handle
pBuffer	pointer to the input data buffer
BufferLength	input data buffer length

Return values

uint32_t

CRC (returned value LSBs for CRC shorter than 32 bits)

Definition at line 483 of file stm32l4xx_hal_crc.c.

{
  uint32_t i;  /* input data buffer index */
  __IO uint16_t *pReg;

  /* Processing time optimization: 2 HalfWords are entered in a row with a single word write,
   * in case of odd length, last HalfWord must be carefully fed to the CRC calculator to ensure
   * a correct type handling by the peripheral */
  for (i = 0U; i < (BufferLength / 2U); i++)
  {
    hcrc->Instance->DR = ((uint32_t)pBuffer[2U * i] << 16U) | (uint32_t)pBuffer[(2U * i) + 1U];
  }
  if ((BufferLength % 2U) != 0U)
  {
    pReg = (__IO uint16_t *)(__IO void *)(&hcrc->Instance->DR);                 /* Derogation MisraC2012 R.11.5 */
    *pReg = pBuffer[2U * i];
  }

  /* Return the CRC computed value */
  return hcrc->Instance->DR;
}

CRC_Handle_8()

static uint32_t CRC_Handle_8 ( CRC_HandleTypeDef *  hcrc, uint8_t  pBuffer[], uint32_t  BufferLength  )

static

Enter 8-bit input data to the CRC calculator. Specific data handling to optimize processing time.

Parameters

hcrc	CRC handle
pBuffer	pointer to the input data buffer
BufferLength	input data buffer length

Return values

uint32_t

CRC (returned value LSBs for CRC shorter than 32 bits)

Definition at line 432 of file stm32l4xx_hal_crc.c.

{
  uint32_t i; /* input data buffer index */
  uint16_t data;
  __IO uint16_t *pReg;

  /* Processing time optimization: 4 bytes are entered in a row with a single word write,
   * last bytes must be carefully fed to the CRC calculator to ensure a correct type
   * handling by the peripheral */
  for (i = 0U; i < (BufferLength / 4U); i++)
  {
    hcrc->Instance->DR = ((uint32_t)pBuffer[4U * i] << 24U) | \
                         ((uint32_t)pBuffer[(4U * i) + 1U] << 16U) | \
                         ((uint32_t)pBuffer[(4U * i) + 2U] << 8U)  | \
                         (uint32_t)pBuffer[(4U * i) + 3U];
  }
  /* last bytes specific handling */
  if ((BufferLength % 4U) != 0U)
  {
    if ((BufferLength % 4U) == 1U)
    {
      *(__IO uint8_t *)(__IO void *)(&hcrc->Instance->DR) = pBuffer[4U * i];         /* Derogation MisraC2012 R.11.5 */
    }
    if ((BufferLength % 4U) == 2U)
    {
      data = ((uint16_t)(pBuffer[4U * i]) << 8U) | (uint16_t)pBuffer[(4U * i) + 1U];
      pReg = (__IO uint16_t *)(__IO void *)(&hcrc->Instance->DR);                    /* Derogation MisraC2012 R.11.5 */
      *pReg = data;
    }
    if ((BufferLength % 4U) == 3U)
    {
      data = ((uint16_t)(pBuffer[4U * i]) << 8U) | (uint16_t)pBuffer[(4U * i) + 1U];
      pReg = (__IO uint16_t *)(__IO void *)(&hcrc->Instance->DR);                    /* Derogation MisraC2012 R.11.5 */
      *pReg = data;

      *(__IO uint8_t *)(__IO void *)(&hcrc->Instance->DR) = pBuffer[(4U * i) + 2U];  /* Derogation MisraC2012 R.11.5 */
    }
  }

  /* Return the CRC computed value */
  return hcrc->Instance->DR;
}