crc32.c

NXP LPC系列AMR7的开发程序源码（LCD

/*****************************************************************************
 *   crc32.c:  Ethernet CRC module file for NXP LPC230x Family Microprocessors
 *
 *   Copyright(C) 2006, NXP Semiconductor
 *   All rights reserved.
 *
 *   History
 *   2006.09.01  ver 1.00    Prelimnary version, first Release
 *
******************************************************************************/
#include <nxp/iolpc2378.h>
#include "type.h"
#include "crc32.h"

/******************************************************************************
** Function name:   CRC_init
**
** Descriptions:    Begin CRC calculation.    
**
** parameters:      pointer to the CRC area.
** Returned value:    None
**
******************************************************************************/
void crc32_init(DWORD *pCRC)
{
  *pCRC = 0xffffffff;
}

/******************************************************************************
** Function name:   CRC32_add
**
** Descriptions:    Calculate CRC value one at a time
**
** parameters:      pointer to the CRC area, and passing value to get the CRC
** Returned value:    None
**
******************************************************************************/
void crc32_add(DWORD *pCRC, BYTE val8)
{
DWORD i, poly;
DWORD entry;
DWORD crc_in;
DWORD crc_out;

  crc_in = *pCRC;
  poly = 0xEDB88320L;
  entry = (crc_in ^ ((DWORD) val8)) & 0xFF;
  for (i = 0; i < 8; i++)
  {
    if (entry & 1)
      entry = (entry >> 1) ^ poly;
    else
      entry >>= 1;
  }
  crc_out = ((crc_in>>8) & 0x00FFFFFF) ^ entry;
  *pCRC = crc_out;
  return;
}

/******************************************************************************
** Function name:   CRC32_end
**
** Descriptions:    Finish CRC calculation
**
** parameters:      pointer to the CRC area.
** Returned value:    None
**
******************************************************************************/
void crc32_end(DWORD *pCRC)
{
  *pCRC ^= 0xffffffff;
}

/******************************************************************************
** Function name:   CRC32_bfr
**
** Descriptions:    Get the CRC value based on size of the string.    
**
** parameters:      Pointer to the string, size of the string.
** Returned value:    CRC value
**
******************************************************************************/
DWORD crc32_bfr(void *pBfr, DWORD size)
{
DWORD crc32;
BYTE  *pu8;

  crc32_init(&crc32);
  pu8 = (BYTE *) pBfr;
  while (size-- != 0)
  {
    crc32_add(&crc32, *pu8);
    pu8++ ;
  }
  crc32_end(&crc32);
  return ( crc32 );
}

/******************************************************************************
** Function name:   do_crc_behav
**
** Descriptions:    calculate CRC
**
** parameters:      MAC address
** Returned value:    CRC value
**
******************************************************************************/
DWORD do_crc_behav( long long Addr )
{
/* state variables */
int crc;
/* declare temporary variables */
int q0, q1, q2, q3;
/* loop variables */
int i, j, d;

  /* calculate CRC */
  crc = 0xFFFFFFFF;
  /* do for each byte */
  for (i = 5; i >= 0; i--)
  {
    d = Addr >> (i * 8);
    for (j = 0; j < 2; j++)
    {
      /* calculate temporary variables */
      /* bits: 26,23,22,16,12,11,10,8,7,5,4,2,1,0 */
      q3 = (((crc >> 28) ^ (d >> 3)) & 0x00000001) ? 0x04C11DB7 : 0x00000000;
      /* bits: 27,24,23,17,13,12,11,9,8,6,5,3,2,1 */
      q2 = (((crc >> 29) ^ (d >> 2)) & 0x00000001) ? 0x09823B6E : 0x00000000;
      /* bits: 28,25,24,18,14,13,12,10,9,7,6,4,3,2 */
      q1 = (((crc >> 30) ^ (d >> 1)) & 0x00000001) ? 0x130476DC : 0x00000000;
      /* bits: 29,26,25,19,15,14,13,11,10,8,7,5,4,3 */
      q0 = (((crc >> 31) ^  d)       & 0x00000001) ? 0x2608EDB8 : 0x00000000;
      /* do crc */
      crc = (crc << 4) ^ q3 ^ q2 ^ q1 ^ q0;
      /* shift data */
      d >>= 4;
    }
  }
  return ( crc );
}

/******************************************************************************
** Function name:   Set_HashValue
**
** Descriptions:    Set Hash value    
**
** parameters:      CRC value
** Returned value:    None
**
******************************************************************************/
void Set_HashValue( DWORD CrcValue )
{
DWORD HashFilterFlag = 0;
DWORD hashMsb6_1;
DWORD hashIndex1;

  hashMsb6_1 = (CrcValue & 0x1f800000);
  hashMsb6_1 = ( (hashMsb6_1 >> 23) & 0x3f);

  if ( hashMsb6_1 >= 32 )
  {
    HashFilterFlag = 1;
    hashMsb6_1 -= 32;
  }

  hashIndex1 = 1 << hashMsb6_1; 

  if(HashFilterFlag == 1)
  {
    HASHFILTERH = hashIndex1;
    HASHFILTERL = 0x0;
  }
  else
  {
    HASHFILTERH = 0x0;
    HASHFILTERL = hashIndex1;
  }

  /* When the Hash filter is enabled, the PassRxFilter bit in MAC_COMMAND
  needs to be enabled too. */
  COMMAND &= ~0x0080;
  return;
}

/*********************************************************************************
**                            End Of File
*********************************************************************************/