共有两种算法。下面这个纯计算出的：
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function CalCRC8005(AData:array of Byte; AStart,AEnd:Integer): Word; const GENP = $8005; var crc:Word; i:Integer; procedure CalOneByte(AByte:Byte); var j:Integer; msb:Word; //移出的最高位 tmp:Word; begin tmp:=AByte; tmp:=tmp shl 8; crc:=crc xor tmp; for j := 0 to 7 do begin msb:= crc and $8000; crc:=crc shl 1; if msb = $8000 then crc:= crc xor GENP; end; end; begin crc:=$FFFF; //crc:=$0000; for i := AStart to AEnd do CalOneByte(AData[i]); Result:=crc; end; |
下面是另一种查表法，结果与第一种一样
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type TForm1 = class(TForm) Button1: TButton; Label1: TLabel; procedure Button1Click(Sender: TObject); private { Private declarations } public { Public declarations } end; const CrcTable: array [0 .. 255] of word = ($0000, $8005, $800F, $000A, $801B, $001E, $0014, $8011, $8033, $0036, $003C, $8039, $0028, $802D, $8027, $0022, $8063, $0066, $006C, $8069, $0078, $807D, $8077, $0072, $0050, $8055, $805F, $005A, $804B, $004E, $0044, $8041, $80C3, $00C6, $00CC, $80C9, $00D8, $80DD, $80D7, $00D2, $00F0, $80F5, $80FF, $00FA, $80EB, $00EE, $00E4, $80E1, $00A0, $80A5, $80AF, $00AA, $80BB, $00BE, $00B4, $80B1, $8093, $0096, $009C, $8099, $0088, $808D, $8087, $0082, $8183, $0186, $018C, $8189, $0198, $819D, $8197, $0192, $01B0, $81B5, $81BF, $01BA, $81AB, $01AE, $01A4, $81A1, $01E0, $81E5, $81EF, $01EA, $81FB, $01FE, $01F4, $81F1, $81D3, $01D6, $01DC, $81D9, $01C8, $81CD, $81C7, $01C2, $0140, $8145, $814F, $014A, $815B, $015E, $0154, $8151, $8173, $0176, $017C, $8179, $0168, $816D, $8167, $0162, $8123, $0126, $012C, $8129, $0138, $813D, $8137, $0132, $0110, $8115, $811F, $011A, $810B, $010E, $0104, $8101, $8303, $0306, $030C, $8309, $0318, $831D, $8317, $0312, $0330, $8335, $833F, $033A, $832B, $032E, $0324, $8321, $0360, $8365, $836F, $036A, $837B, $037E, $0374, $8371, $8353, $0356, $035C, $8359, $0348, $834D, $8347, $0342, $03C0, $83C5, $83CF, $03CA, $83DB, $03DE, $03D4, $83D1, $83F3, $03F6, $03FC, $83F9, $03E8, $83ED, $83E7, $03E2, $83A3, $03A6, $03AC, $83A9, $03B8, $83BD, $83B7, $03B2, $0390, $8395, $839F, $039A, $838B, $038E, $0384, $8381, $0280, $8285, $828F, $028A, $829B, $029E, $0294, $8291, $82B3, $02B6, $02BC, $82B9, $02A8, $82AD, $82A7, $02A2, $82E3, $02E6, $02EC, $82E9, $02F8, $82FD, $82F7, $02F2, $02D0, $82D5, $82DF, $02DA, $82CB, $02CE, $02C4, $82C1, $8243, $0246, $024C, $8249, $0258, $825D, $8257, $0252, $0270, $8275, $827F, $027A, $826B, $026E, $0264, $8261, $0220, $8225, $822F, $022A, $823B, $023E, $0234, $8231, $8213, $0216, $021C, $8219, $0208, $820D, $8207, $0202); var Form1: TForm1; CrcL, CrcH: byte; implementation {$R *.dfm} procedure ResetCrc; begin CrcL := $FF; CrcH := $FF; end; procedure UpdateCrc(const num: byte); var table_addr: byte; begin table_addr := (num xor CrcH); CrcH := (CrcTable[table_addr] shr 8) xor CrcL; CrcL := (CrcTable[table_addr] and $00FF); end; procedure TForm1.Button1Click(Sender: TObject); var i0, s_len: integer; WrBuf: array [1 .. 32] of byte; s:string; begin s:=''; WrBuf[1] := $7F; WrBuf[2] := $80; WrBuf[3] := $01; WrBuf[4] := $07; //WrBuf[5] := $ef; //WrBuf[6] := $00; ResetCrc; for i0 := 2 to 4 do UpdateCrc(WrBuf[i0]); // 计算 Crc，0x7f 不参加 Crc 计算 WrBuf[i0] := CrcL; inc(i0); WrBuf[i0] := CrcH; s_len := i0; for i0 := 1 to s_len do s:=s+inttohex(WrBuf[i0],2)+' '; label1.Caption := s; end; end. |
