CCITT CRC-16校验程序怎么实现？

Question

CRC-CCITT码: G(x)=X16+X12+X5+1

Answer 1

unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs;type
  TForm1 = class(TForm)
  private
    Function VerifyCRCITU(sData:String):Boolean;Overload;
    Function VerifyCRCITU(pData:Array of Byte):Boolean;Overload;
  public
    { Public declarations }
  end;var
  Form1: TForm1;implementation{$R *.dfm}{ TForm1 }const
  CCrcITUTable:Array[0..$FF] of Word =
  ( $0000, $1189, $2312, $329B, $4624, $57AD, $6536, $74BF,
    $8C48, $9DC1, $AF5A, $BED3, $CA6C, $DBE5, $E97E, $F8F7,
    $1081, $0108, $3393, $221A, $56A5, $472C, $75B7, $643E,
    $9CC9, $8D40, $BFDB, $AE52, $DAED, $CB64, $F9FF, $E876,
    $2102, $308B, $0210, $1399, $6726, $76AF, $4434, $55BD,
    $AD4A, $BCC3, $8E58, $9FD1, $EB6E, $FAE7, $C87C, $D9F5,
    $3183, $200A, $1291, $0318, $77A7, $662E, $54B5, $453C,
    $BDCB, $AC42, $9ED9, $8F50, $FBEF, $EA66, $D8FD, $C974,
    $4204, $538D, $6116, $709F, $0420, $15A9, $2732, $36BB,
    $CE4C, $DFC5, $ED5E, $FCD7, $8868, $99E1, $AB7A, $BAF3,
    $5285, $430C, $7197, $601E, $14A1, $0528, $37B3, $263A,
    $DECD, $CF44, $FDDF, $EC56, $98E9, $8960, $BBFB, $AA72,
    $6306, $728F, $4014, $519D, $2522, $34AB, $0630, $17B9,
    $EF4E, $FEC7, $CC5C, $DDD5, $A96A, $B8E3, $8A78, $9BF1,
    $7387, $620E, $5095, $411C, $35A3, $242A, $16B1, $0738,
    $FFCF, $EE46, $DCDD, $CD54, $B9EB, $A862, $9AF9, $8B70,
    $8408, $9581, $A71A, $B693, $C22C, $D3A5, $E13E, $F0B7,
    $0840, $19C9, $2B52, $3ADB, $4E64, $5FED, $6D76, $7CFF,
    $9489, $8500, $B79B, $A612, $D2AD, $C324, $F1BF, $E036,
    $18C1, $0948, $3BD3, $2A5A, $5EE5, $4F6C, $7DF7, $6C7E,
    $A50A, $B483, $8618, $9791, $E32E, $F2A7, $C03C, $D1B5,
    $2942, $38CB, $0A50, $1BD9, $6F66, $7EEF, $4C74, $5DFD,
    $B58B, $A402, $9699, $8710, $F3AF, $E226, $D0BD, $C134,
    $39C3, $284A, $1AD1, $0B58, $7FE7, $6E6E, $5CF5, $4D7C,
    $C60C, $D785, $E51E, $F497, $8028, $91A1, $A33A, $B2B3,
    $4A44, $5BCD, $6956, $78DF, $0C60, $1DE9, $2F72, $3EFB,
    $D68D, $C704, $F59F, $E416, $90A9, $8120, $B3BB, $A232,
    $5AC5, $4B4C, $79D7, $685E, $1CE1, $0D68, $3FF3, $2E7A,
    $E70E, $F687, $C41C, $D595, $A12A, $B0A3, $8238, $93B1,
    $6B46, $7ACF, $4854, $59DD, $2D62, $3CEB, $0E70, $1FF9,
    $F78F, $E606, $D49D, $C514, $B1AB, $A022, $92B9, $8330,
    $7BC7, $6A4E, $58D5, $495C, $3DE3, $2C6A, $1EF1, $0F78);function TForm1.VerifyCRCITU(sData: String): Boolean;
var
  pData:Array of Byte;
  iCount:Integer;
begin
  SetLength(pData,Length(sData));
  for iCount:=1 to Length(sData) do pData[iCount-1]:=Ord(sData[iCount]);  Result:=VerifyCRCITU(pData);
end;function TForm1.VerifyCRCITU(pData: array of Byte): Boolean;
var
  wTemp:Word;
  iCount:integer;
begin
  wTemp := $FFFF;    // 初始化  for iCount:=0 to High(pData) do
    wTemp := (wTemp shr 8) xor CCrcITUTable[(wTemp xor pData[iCount]) and $FF];  if wTemp = $F0B8 then// F0B8是CRC-ITU的"Magic Value"
    Result:=true
  else
    Result:=false;
end;end.

Answer 2

兄弟：
你的函数不符合要求哦var
buf:array[1..4]  of byte;
begin
buf[1]:=$2A;
buf[2]:=$91;
buf[3]:=$01;
buf[4]:=$23;
showmessage(IntToHex(crc16(buf),4));//结果应该是十六进制 BC19    =    48153
end;

Answer 3

unit UCRC16;interface
type
    //CRC的数据结构
    TMyCRC = record                   //position
      Lowbyte: byte;                  //1
      Highbyte:  Byte;                //2
    end;
Const
  CRCL:array [0..255] of byte=(
        $00,$21,$42,$63,$84,$A5,$C6,$E7,$08,$29,$4A,$6B,$8C,$AD,$CE,$EF,
        $31,$10,$73,$52,$B5,$94,$F7,$D6,$39,$18,$7B,$5A,$BD,$9C,$FF,$DE,
        $62,$43,$20,$01,$E6,$C7,$A4,$85,$6A,$4B,$28,$09,$EE,$CF,$AC,$8D,
        $53,$72,$11,$30,$D7,$F6,$95,$B4,$5B,$7A,$19,$38,$DF,$FE,$9D,$BC,
        $C4,$E5,$86,$A7,$40,$61,$02,$23,$CC,$ED,$8E,$AF,$48,$69,$0A,$2B,
        $F5,$D4,$B7,$96,$71,$50,$33,$12,$FD,$DC,$BF,$9E,$79,$58,$3B,$1A,
        $A6,$87,$E4,$C5,$22,$03,$60,$41,$AE,$8F,$EC,$CD,$2A,$0B,$68,$49,
        $97,$B6,$D5,$F4,$13,$32,$51,$70,$9F,$BE,$DD,$FC,$1B,$3A,$59,$78,
        $88,$A9,$CA,$EB,$0C,$2D,$4E,$6F,$80,$A1,$C2,$E3,$04,$25,$46,$67,
        $B9,$98,$FB,$DA,$3D,$1C,$7F,$5E,$B1,$90,$F3,$D2,$35,$14,$77,$56,
        $EA,$CB,$A8,$89,$6E,$4F,$2C,$0D,$E2,$C3,$A0,$81,$66,$47,$24,$05,
        $DB,$FA,$99,$B8,$5F,$7E,$1D,$3C,$D3,$F2,$91,$B0,$57,$76,$15,$34,
        $4C,$6D,$0E,$2F,$C8,$E9,$8A,$AB,$44,$65,$06,$27,$C0,$E1,$82,$A3,
        $7D,$5C,$3F,$1E,$F9,$D8,$BB,$9A,$75,$54,$37,$16,$F1,$D0,$B3,$92,
        $2E,$0F,$6C,$4D,$AA,$8B,$E8,$C9,$26,$07,$64,$45,$A2,$83,$E0,$C1,
        $1F,$3E,$5D,$7C,$9B,$BA,$D9,$F8,$17,$36,$55,$74,$93,$B2,$D1,$F0);  CRCH:array [0..255] of byte=(
        $00,$10,$20,$30,$40,$50,$60,$70,$81,$91,$A1,$B1,$C1,$D1,$E1,$F1,
        $12,$02,$32,$22,$52,$42,$72,$62,$93,$83,$B3,$A3,$D3,$C3,$F3,$E3,
        $24,$34,$04,$14,$64,$74,$44,$54,$A5,$B5,$85,$95,$E5,$F5,$C5,$D5,
        $36,$26,$16,$06,$76,$66,$56,$46,$B7,$A7,$97,$87,$F7,$E7,$D7,$C7,
        $48,$58,$68,$78,$08,$18,$28,$38,$C9,$D9,$E9,$F9,$89,$99,$A9,$B9,
        $5A,$4A,$7A,$6A,$1A,$0A,$3A,$2A,$DB,$CB,$FB,$EB,$9B,$8B,$BB,$AB,
        $6C,$7C,$4C,$5C,$2C,$3C,$0C,$1C,$ED,$FD,$CD,$DD,$AD,$BD,$8D,$9D,
        $7E,$6E,$5E,$4E,$3E,$2E,$1E,$0E,$FF,$EF,$DF,$CF,$BF,$AF,$9F,$8F,
        $91,$81,$B1,$A1,$D1,$C1,$F1,$E1,$10,$00,$30,$20,$50,$40,$70,$60,
        $83,$93,$A3,$B3,$C3,$D3,$E3,$F3,$02,$12,$22,$32,$42,$52,$62,$72,
        $B5,$A5,$95,$85,$F5,$E5,$D5,$C5,$34,$24,$14,$04,$74,$64,$54,$44,
        $A7,$B7,$87,$97,$E7,$F7,$C7,$D7,$26,$36,$06,$16,$66,$76,$46,$56,
        $D9,$C9,$F9,$E9,$99,$89,$B9,$A9,$58,$48,$78,$68,$18,$08,$38,$28,
        $CB,$DB,$EB,$FB,$8B,$9B,$AB,$BB,$4A,$5A,$6A,$7A,$0A,$1A,$2A,$3A,
        $FD,$ED,$DD,$CD,$BD,$AD,$9D,$8D,$7C,$6C,$5C,$4C,$3C,$2C,$1C,$0C,
        $EF,$FF,$CF,$DF,$AF,$BF,$8F,$9F,$6E,$7E,$4E,$5E,$2E,$3E,$0E,$1E);
    Function BuffCalCulateCRC(InputBuff:Pchar;BuffLen:integer):TMyCRC;//计算CRCimplementation//计算长度为BuffLen，下标从0开始的数组的CRC校验值
Function BuffCalCulateCRC(InputBuff:Pchar;BuffLen:integer):TMyCRC;//计算CRC
var
  i,j:integer;
  Charx:array[0..1023] of char;
  btt1,Btmp:byte;
  T1,T2,T3:byte;
  Rt:TMyCRC;
begin
  for j:=0 to Bufflen-1 do begin
    charx[j]:=inputBuff[j];
  end;
  charx[BuffLen]:=#0;
  Charx[BuffLen+1]:=#0;  T1:=byte(charx[0]);
  T2:=byte(charx[1]);
  for  i:=2 to Bufflen+1  do begin
    T3:=byte(charx[i]);
    Btmp:=T1;
    Btt1:=CRCH[Btmp];
    T1:=Btt1 Xor T2;
    Btt1:=CRCL[Btmp];
    T2:=Btt1 xor T3;
  end;
//  Result:=(T1 shl 8) +T2;
  Rt.Highbyte:=T1;
  Rt.Lowbyte:=T2;
  Result:=Rt;
end;end.