crc_cal.c

VISA卡校验值CVV及PIN校验值PVV的计算

#include <intrins.h>
#include <string.h>
#include <absacc.h>
#include "reg52.h"

#define uchar	unsigned char
#define uint	unsigned int
#define ulong	unsigned long

typedef union { uint word;
                struct{uchar Hi;uchar Lo;} byte;
              } UNST;
UNST crc_value;
uint code crc_tab[256] =
    {
    0x0000,0xc0c1,0xc181,0x0140,0xc301,0x03c0,0x0280,0xc241,
    0xc601,0x06c0,0x0780,0xc741,0x0500,0xc5c1,0xc481,0x0440,
    0xcc01,0x0cc0,0x0d80,0xcd41,0x0f00,0xcfc1,0xce81,0x0e40,
    0x0a00,0xcac1,0xcb81,0x0b40,0xc901,0x09c0,0x0880,0xc841,
    0xd801,0x18c0,0x1980,0xd941,0x1b00,0xdbc1,0xda81,0x1a40,
    0x1e00,0xdec1,0xdf81,0x1f40,0xdd01,0x1dc0,0x1c80,0xdc41,
    0x1400,0xd4c1,0xd581,0x1540,0xd701,0x17c0,0x1680,0xd641,
    0xd201,0x12c0,0x1380,0xd341,0x1100,0xd1c1,0xd081,0x1040,
    0xf001,0x30c0,0x3180,0xf141,0x3300,0xf3c1,0xf281,0x3240,
    0x3600,0xf6c1,0xf781,0x3740,0xf501,0x35c0,0x3480,0xf441,
    0x3c00,0xfcc1,0xfd81,0x3d40,0xff01,0x3fc0,0x3e80,0xfe41,
    0xfa01,0x3ac0,0x3b80,0xfb41,0x3900,0xf9c1,0xf881,0x3840,
    0x2800,0xe8c1,0xe981,0x2940,0xeb01,0x2bc0,0x2a80,0xea41,
    0xee01,0x2ec0,0x2f80,0xef41,0x2d00,0xedc1,0xec81,0x2c40,
    0xe401,0x24c0,0x2580,0xe541,0x2700,0xe7c1,0xe681,0x2640,
    0x2200,0xe2c1,0xe381,0x2340,0xe101,0x21c0,0x2080,0xe041,
    0xa001,0x60c0,0x6180,0xa141,0x6300,0xa3c1,0xa281,0x6240,
    0x6600,0xa6c1,0xa781,0x6740,0xa501,0x65c0,0x6480,0xa441,
    0x6c00,0xacc1,0xad81,0x6d40,0xaf01,0x6fc0,0x6e80,0xae41,
    0xaa01,0x6ac0,0x6b80,0xab41,0x6900,0xa9c1,0xa881,0x6840,
    0x7800,0xb8c1,0xb981,0x7940,0xbb01,0x7bc0,0x7a80,0xba41,
    0xbe01,0x7ec0,0x7f80,0xbf41,0x7d00,0xbdc1,0xbc81,0x7c40,
    0xb401,0x74c0,0x7580,0xb541,0x7700,0xb7c1,0xb681,0x7640,
    0x7200,0xb2c1,0xb381,0x7340,0xb101,0x71c0,0x7080,0xb041,
    0x5000,0x90c1,0x9181,0x5140,0x9301,0x53c0,0x5280,0x9241,
    0x9601,0x56c0,0x5780,0x9741,0x5500,0x95c1,0x9481,0x5440,
    0x9c01,0x5cc0,0x5d80,0x9d41,0x5f00,0x9fc1,0x9e81,0x5e40,
    0x5a00,0x9ac1,0x9b81,0x5b40,0x9901,0x59c0,0x5880,0x9841,
    0x8801,0x48c0,0x4980,0x8941,0x4b00,0x8bc1,0x8a81,0x4a40,
    0x4e00,0x8ec1,0x8f81,0x4f40,0x8d01,0x4dc0,0x4c80,0x8c41,
    0x4400,0x84c1,0x8581,0x4540,0x8701,0x47c0,0x4680,0x8641,
    0x8201,0x42c0,0x4380,0x8341,0x4100,0x81c1,0x8081,0x4040,
    };

/*--------------------------------------------------------------
crc校验
	入口参数:
		length == 被校验buffer长度
		clear  == 1
		buffer == 被校验的数据
	出口参数:
		== crc校验值

--------------------------------------------------------------*/
uint crcxdata(uint length,uchar clear,void *buffer)
{
	UNST	temp;
	if(clear)	crc_value.word=0;
	do
	{
		temp.byte.Hi=0;
		temp.byte.Lo=crc_value.byte.Hi;
		crc_value.word= temp.word^crc_tab[crc_value.byte.Lo^(*(uchar *)buffer)];
		((uchar *)buffer)++;
	}while(--length);
	return crc_value.word;
}