CRC 8 berechnen ?

[himitsu]

http://www.mikrocontroller.net/topic/9929

für CRC8 macht sich ein Byte doch eigentlich schon besser?
jedenfalls wäre es vollkommen ausreichend

[add]
dort hast du ein Beispiel für's DEC und müßtest dann wohl CRC_8 oder was Ähnliches als Type verwenden
http://www.delphipraxis.net/internal...highlight=crc8

Delphi-Quellcode:

const
  CRC8Table: array[0..255] of Byte = (
    $00, $07, $0E, $09, $1C, $1B, $12, $15,
    $38, $3F, $36, $31, $24, $23, $2A, $2D,
    $70, $77, $7E, $79, $6C, $6B, $62, $65,
    $48, $4F, $46, $41, $54, $53, $5A, $5D,
    $E0, $E7, $EE, $E9, $FC, $FB, $F2, $F5,
    $D8, $DF, $D6, $D1, $C4, $C3, $CA, $CD,
    $90, $97, $9E, $99, $8C, $8B, $82, $85,
    $A8, $AF, $A6, $A1, $B4, $B3, $BA, $BD,
    $C7, $C0, $C9, $CE, $DB, $DC, $D5, $D2,
    $FF, $F8, $F1, $F6, $E3, $E4, $ED, $EA,
    $B7, $B0, $B9, $BE, $AB, $AC, $A5, $A2,
    $8F, $88, $81, $86, $93, $94, $9D, $9A,
    $27, $20, $29, $2E, $3B, $3C, $35, $32,
    $1F, $18, $11, $16, $03, $04, $0D, $0A,
    $57, $50, $59, $5E, $4B, $4C, $45, $42,
    $6F, $68, $61, $66, $73, $74, $7D, $7A,
    $89, $8E, $87, $80, $95, $92, $9B, $9C,
    $B1, $B6, $BF, $B8, $AD, $AA, $A3, $A4,
    $F9, $FE, $F7, $F0, $E5, $E2, $EB, $EC,
    $C1, $C6, $CF, $C8, $DD, $DA, $D3, $D4,
    $69, $6E, $67, $60, $75, $72, $7B, $7C,
    $51, $56, $5F, $58, $4D, $4A, $43, $44,
    $19, $1E, $17, $10, $05, $02, $0B, $0C,
    $21, $26, $2F, $28, $3D, $3A, $33, $34,
    $4E, $49, $40, $47, $52, $55, $5C, $5B,
    $76, $71, $78, $7F, $6A, $6D, $64, $63,
    $3E, $39, $30, $37, $22, $25, $2C, $2B,
    $06, $01, $08, $0F, $1A, $1D, $14, $13,
    $AE, $A9, $A0, $A7, $B2, $B5, $BC, $BB,
    $96, $91, $98, $9F, $8A, $8D, $84, $83,
    $DE, $D9, $D0, $D7, $C2, $C5, $CC, $CB,
    $E6, $E1, $E8, $EF, $FA, $FD, $F4, $F3);

function CRC8(const s: ansistring): Byte;
var
  i, iLen, iStep: Integer;
begin
  Result := 0;
  iLen := Length(s);
  if iLen < 32 then
  begin
    for i := 1 to iLen do
    begin
      Result := CRC8Table[Result xor Byte(s[i])];
    end;
  end
  else
  begin
    iStep := iLen div 32 + 1;
    i := 1;
    while i < iLen do
    begin
      Result := CRC8Table[Result xor Byte(s[i])];
      Inc(i, iStep);
    end;
  end;
end;

wobei mir die Berechnung, bei 32 und mehr Zeichen, eigenartig vorkommt
und ich es daher auch mal nur so probieren würde

Delphi-Quellcode:

function CRC8(const s: ansistring): Byte;
var
  i: Integer;
begin
  Result := 0;
  for i := 1 to Length(s) do
    Result := CRC8Table[Result xor Byte(s[i])];
end;