crc-12校验法.txt

Modbus RTU 的C语言程序

CRC12  查表算法C     
/******** UInt CheckSummat(ucahr *p,UInt len) ********/
/*函数名称:CheckSummat									*/
/*函数功能:以CRC-12来求一组数据的校验码						*/
/*入口参数:数据首地址										*/
/*出口参数:校验字											*/
/*资源:					 								*/
/*子函数:	无											*/ 
/******************** CheckSummat ***********************/   

uint CheckSummat(UChar *p,UInt len)
{
	uchar *pt=p;
	uint crc=0,i=0;
	uchar da=0;
	while(i<len)
	{
		da=(UChar)(crc/0x10);
		crc<<=8;
		crc^=crc256table[da^pt[i]];
		crc&=0x0fff; 
		i++;
	}
	return(crc);
}

CRC12 数据表            校验多项式: 0x18D0

uint code crc256table[256]=
{
0X0000,0X080d,0X0817,0X001a,0X0823,0X002e,0X0034,0X0839,0X084b,0X0046,0X005c,0X0851,0X0068,0X0865,0X087f,0X0072,
0X089b,0X0096,0X008c,0X0881,0X00b8,0X08b5,0X08af,0X00a2,0X00d0,0X08dd,0X08c7,0X00ca,0X08f3,0X00fe,0X00e4,0X08e9,
0X093b,0X0136,0X012c,0X0921,0X0118,0X0915,0X090f,0X0102,0X0170,0X097d,0X0967,0X016a,0X0953,0X015e,0X0144,0X0949,
0X01a0,0X09ad,0X09b7,0X01ba,0X0983,0X018e,0X0194,0X0999,0X09eb,0X01e6,0X01fc,0X09f1,0X01c8,0X09c5,0X09df,0X01d2,
0X0a7b,0X0276,0X026c,0X0a61,0X0258,0X0a55,0X0a4f,0X0242,0X0230,0X0a3d,0X0a27,0X022a,0X0a13,0X021e,0X0204,0X0a09,
0X02e0,0X0aed,0X0af7,0X02fa,0X0ac3,0X02ce,0X02d4,0X0ad9,0X0aab,0X02a6,0X02bc,0X0ab1,0X0288,0X0a85,0X0a9f,0X0292,
0X0340,0X0b4d,0X0b57,0X035a,0X0b63,0X036e,0X0374,0X0b79,0X0b0b,0X0306,0X031c,0X0b11,0X0328,0X0b25,0X0b3f,0X0332,
0X0bdb,0X03d6,0X03cc,0X0bc1,0X03f8,0X0bf5,0X0bef,0X03e2,0X0390,0X0b9d,0X0b87,0X038a,0X0bb3,0X03be,0X03a4,0X0ba9,
0X0cfb,0X04f6,0X04ec,0X0ce1,0X04d8,0X0cd5,0X0ccf,0X04c2,0X04b0,0X0cbd,0X0ca7,0X04aa,0X0c93,0X049e,0X0484,0X0c89,
0X0460,0X0c6d,0X0c77,0X047a,0X0c43,0X044e,0X0454,0X0c59,0X0c2b,0X0426,0X043c,0X0c31,0X0408,0X0c05,0X0c1f,0X0412,
0X05c0,0X0dcd,0X0dd7,0X05da,0X0de3,0X05ee,0X05f4,0X0df9,0X0d8b,0X0586,0X059c,0X0d91,0X05a8,0X0da5,0X0dbf,0X05b2,
0X0d5b,0X0556,0X054c,0X0d41,0X0578,0X0d75,0X0d6f,0X0562,0X0510,0X0d1d,0X0d07,0X050a,0X0d33,0X053e,0X0524,0X0d29,
0X0680,0X0e8d,0X0e97,0X069a,0X0ea3,0X06ae,0X06b4,0X0eb9,0X0ecb,0X06c6,0X06dc,0X0ed1,0X06e8,0X0ee5,0X0eff,0X06f2,
0X0e1b,0X0616,0X060c,0X0e01,0X0638,0X0e35,0X0e2f,0X0622,0X0650,0X0e5d,0X0e47,0X064a,0X0e73,0X067e,0X0664,0X0e69,
0X0fbb,0X07b6,0X07ac,0X0fa1,0X0798,0X0f95,0X0f8f,0X0782,0X07f0,0X0ffd,0X0fe7,0X07ea,0X0fd3,0X07de,0X07c4,0X0fc9,
0X0720,0X0f2d,0X0f37,0X073a,0X0f03,0X070e,0X0714,0X0f19,0X0f6b,0X0766,0X077c,0X0f71,0X0748,0X0f45,0X0f5f,0X0752,
}