求 CRC-8 算法 ， Help me !! －－－－》诶，还是要考自己弄明白原理，自己写程序。也好。我贴出了我的CRC-8算法 (100分)

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VByte:array [0..6] of byte;
Vbyte[0]:=$02;
Vbyte[1]:=$8f;
Vbyte[2]:=$d2;
Vbyte[3]:=$b3;
Vbyte[4]:=$00;
Vbyte[5]:=$00;
Vbyte[6]:=$00;
求 8位CRC校验
CRC-8 多项式G（X）= X8+X6+X2+1
( CRC-8 的多项式是否采用 G（X）= X8+X6+X2+1？？）

急求：
1、查表算法
2、直接算法

Byte = 0x02 Check = 0x0e
Byte = 0x8f Check = 0x8e
Byte = 0xd2 Check = 0x93
Byte = 0xb3 Check = 0xe0
Byte = 0x00 Check = 0xae
Byte = 0x00 Check = 0x43
Byte = 0x00 Check = 0xce

LeeChange：
能否给出算法？

你不是写出了嘛.
C(x)=x^8+x^6+x^2+1

gg

LeeChange：
我想了解过程，程序实现

查表吧:
unsigned int cal_crc(unsigned char *ptr, unsigned char len) {
unsigned int crc;
unsigned char da;
unsigned int crc_ta[256]={ /* CRC余式表 */
0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
0x 1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6,
0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de,
0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485,
0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d,
0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4,
0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc,
0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823,
0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b,
0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12,
0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a,
0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41,
0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49,
0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70,
0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78,
0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f,
0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e,
0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256,
0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d,
0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c,
0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634,
0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab,
0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3,
0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92,
0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9,
0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1,
0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8,
0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0
};

crc=0;
while(len--!=0) {
da=(uchar) (crc/256);
crc<<=8;
crc^=crc_ta[da^*ptr];
ptr++;
}
return(crc);
}

LeeChange：
Byte = 0x02 Check = 0x0e
Byte = 0x8f Check = 0x8e
Byte = 0xd2 Check = 0x93
Byte = 0xb3 Check = 0xe0
Byte = 0x00 Check = 0xae
Byte = 0x00 Check = 0x43
Byte = 0x00 Check = 0xce

出不来
我的初始值 设为 $0
计出Crc-8 多项式码位 $A2

help!!!

LeeChange：
谢。
有没有直接算法?

听听

呵呵,真能刨根问底:
unsigned int cal_crc(unsigned char *ptr, unsigned char len) {
unsigned char i;
unsigned int crc=0;
while(len--!=0) {
for(i=0x80; i!=0; i/=2) {
if((crc&amp;0x8000)!=0) {crc*=2; crc^=0x1021;}
else crc*=2;
if((*ptr&amp;i)!=0) crc^=0x1021;
}
ptr++;
}
return(crc);
}

LeeChange：
帮忙瞧瞧：

var
VByte:array [0..6] of byte;
x,y:integer;
savb:byte;
Tmp:byte;
begin
Tmp:=$00;
VByte[0]:=$02;
VByte[1]:=$8f;
VByte[2]:=$d2;
VByte[3]:=$b3;
VByte[4]:=$00;
VByte[5]:=$00;
VByte[6]:=$00;

for x:=0 to 6 do
begin
tmp:=Tmp xor Vbyte[x];
for y:=0 to 7 do
begin
savb:=tmp;
tmp:=tmp shr 1;
if (savb and $01)=1 then
begin
tmp:=tmp xor $A2;
end;
end;
end;

showmessage(inttohex(tmp,2));

算出的结果与你给出的不一致，请问，程序那里出错。

还是自己弄出来了。
1、多项式取错了：)) 现在采用G（X）= X8+X5+X4+1

2、贴自己的程序出来了

var
VByte:array [0..6] of byte;
x,y:integer;
CRC8,SaveCrc:byte;
begin
VByte[0]:=$02;
VByte[1]:=$8f;
VByte[2]:=$d2;
VByte[3]:=$b3;
VByte[4]:=$00;
VByte[5]:=$00;
VByte[6]:=$00;

CRC8:= $00;
for X:=0 to 6 do
begin
CRC8:= CRC8 Xor Vbyte[X];//每一个数据与CRC寄存器进行异或
For y:= 0 To 7 do
begin
SaveCrc:=CRC8;
CRC8:=CRC8 shr 1; //右移一位
If ((SaveCrc And $1)=$1) Then //如果LSB为1，则与多项式码进行异或
begin
CRC8:=CRC8 Xor $8C ;
end;
end;
end;
showmessage(inttohex(CRC8,2));
end;

结果 CRC-8 ==> $70

不过也要谢谢LeeChange。（你给的好像是 16位CRC的哦！！！）
：》》》

接受答案了.