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C51編程:那位大俠有CRC的c51快速算法和源程序？ [guojian6] [34次] 01-11-29 下午 01:45:36
   我的email是guojian6@cmmail.com，不甚感謝！ 

我有一個匯編的CRC16程序，很精煉的。 [vagabond] [47次] 01-11-29 下午 03:02:06 
;這個程序的C原程序是我一個朋友XuChen寫的。以后找到的話再貼出來。
;$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
;
;Function: CRC16    ,ÄÚ²¿º¯Êý
;
;Input : 
;     r7 : length.
;     dptr is Source    point.
;Output:r5,r6 =    crc16 low,high
CalcCRC:
CRCCCITT:
    mov    r5,#0ffh
    mov    r6,#0ffh

;$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
;
;Function: CRC16    ;ÄÚ²¿º¯Êý
;
;Input : r5,r6 = start crc.
;     r7 : length.
;     dptr is Source    point.
;Output:r5,r6 =    crc16 low,high
;    dptr is    next byte.
CalcCRC1:
CRCCCITT1:

    movx    a,@dptr
           inc       dptr


    mov    b,a
    mov    r3,#2

CRCCCITT2:
    xrl    a,r5
    anl    a,#0fh
    rl    a    ;a*2
    mov    r1,a
    add    a,#(Crc_Table-Crc_TablePc1)
    movc    a,@a+pc
Crc_TablePc1:
    mov    r2,a

    mov    a,r1
    inc    a
    add    a,#(Crc_Table-Crc_TablePc2)
    movc    a,@a+pc
Crc_TablePc2:
    mov    r1,a    

    mov    a,r6
    anl    a,#0f0h
    swap    a
    xch    a,r6    
    anl    a,#0fh
    swap    a    
    xch    a,r5    
    anl    a,#0f0h
    swap    a    
    orl    a,r5    

    xrl    a,r1
    mov    r5,a    

    mov    a,r2
    xrl    a,r6
    mov    r6,a

    mov    a,b
    swap    a
    djnz    r3,CRCCCITT2
        
    djnz    r7,CRCCCITT1

    ret
        
Crc_Table:    dw    0,1081h,2102h,3183h
    dw    4204h,5285h,6306h,7387h
    dw    8408h,9489h,0a50ah,0b58bh
    dw    0c60ch,0d68dh,0e70eh,0f78fh

;End of    fCRC16
;$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$


謝了，可惜沒有用，我不大會用匯編 [guojian6] [2次] 01-11-29 下午 08:59:51 

好吧，給你個C51的，怎么樣？ [shiaf] [45次] 01-11-30 上午 08:39:30 
#pragma small
#include <reg52.h>

unsigned int CRC_16(unsigned int c,unsigned char d);

void main(void)
{
    unsigned char crcbuff[] = {31,3,0,1,0,7};
    unsigned char a;
    unsigned int crc16 = 0xffff;
    for(a=0;a<6;a++)
    {
        crc16 = CRC_16(crc16,crcbuff[a]);
    }
}

unsigned int CRC_16(unsigned int c,unsigned char d)
{
    unsigned int data e;
    unsigned char data f;
    e = c^(unsigned int)d;
    for(f=0;f<8;f++)
    {
        if(e&1)
        {
            e >>= 1;
            e ^= 0xa001;
        }
        else e >>= 1;
    }
    return e;
} 

還可以用查表法 [邦故] [30次] 01-12-1 上午 11:52:47 
/*
 *  Crc calculation stuff
 */

/* crctab calculated by Mark G. Mendel, Network Systems Corporation */
code unsigned short crctab[256] = {
    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
};

/*
 * updcrc macro derived from article Copyright (C) 1986 Stephen Satchell. 
 *  NOTE: First srgument must be in range 0 to 255.
 *        Second argument is referenced twice.
 * 
 * Programmers may incorporate any or all code into their programs, 
 * giving proper credit within the source. Publication of the 
 * source routines is permitted so long as proper credit is given 
 * to Stephen Satchell, Satchell Evaluations and Chuck Forsberg, 
 * Omen Technology.
 */

#define updcrc(cp, crc) ( crctab[((crc >> 8) & 255)] ^ (crc << 8) ^ cp)

/* End of crctab.c */

 

 
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