The code is as follows, using space-changing methods
#defineCrc16_ccitt_seed 0xFFFF//This bit is called a preset value, and the use of artificial algorithms (long division) requires that the divisor polynomial be preceded by the position XOR, in order to get the last divisor polynomial#defineCRC16_CCITT_POLY16 0x1021//This bit is a simple writing practice for 0x11021unsigned ShortCrc16_ccitt (unsignedChar*pbuf, size_t len);//*pbuf is the data pointer, Len is the data length/**CRC Excess Table*/StaticUnsigned Shortcrc16_ccitt_table[ the] ={ 0x0000,0x1021,0x2042,0x3063,0x4084,0x50a5,0x60c6,0x70e7, 0x8108,0x9129,0xa14a,0xb16b,0xc18c,0XD1AD,0xe1ce,0xf1ef, 0x1231,0x0210,0x3273,0x2252,0x52b5,0x4294,0x72f7,0X62D6, 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 Check code generation function// */Unsigned ShortCrc16_ccitt (unsignedChar*pbuf, size_t len) {unsigned ShortCRC =Crc16_ccitt_seed; while(len-->0) {CRC= crc16_ccitt_table[(CRC >>8^ *pbuf++) &0xFF] ^ (CRC <<8); } returnCRC;}
Test it.
intMainvoid) {unsignedChar string[8]= {0x02,0x0A,0x00,0x03,0xe6,0x02,0x08,0x03}; unsigned ShortCrc_value; Crc_value= Crc16_ccitt (string,8);//Get CRC valueprintf"Crc_value:%04x\n", Crc_value);//output is 16 binarySystem ("Pause"); return 0;}
The results are as follows:
Crc16-ccitt C language Code