XProfan

CLS
Def %CRC8POLY  $18' 0X18 = X^8+X^5+X^4+X^0
Var CRC8_Sp% = 0' CRC8 memory

proc CRC8_berechnen

    Parameters crc_data%' Übergabe data
    Var bit_counter% = 8' Schleifendurchlauf
    Var feedback_bit% = 0' bit Return

    while bit_counter% > 0' 8x Durchläufe

        feedback_bit% = Xor(CRC8_Sp%,crc_data%) & $01' XOR on 1 to check on

        if feedback_bit% = $01' if 1, then...

            CRC8_Sp% = Xor(CRC8_Sp%,%CRC8POLY)' XOR with Poly

        EndIf

        CRC8_Sp% = (CRC8_Sp% >> 1) & $7F' Invoice values right & 247

        if feedback_bit% = $01' if 1, then...

            CRC8_Sp% = CRC8_Sp% | $80' ODER 128

        EndIf

        crc_data% = crc_data% >> 1' data Invoice values right
        Dec bit_counter%' Schleifendurchlauf -1

    EndWhile' end Endlosschleife

endproc

' Test appeal
CRC8_Sp% = 0' Reset CRC8 memory

WhileLoop 0,255' Chr$(0) To Chr$(255) go through

    CRC8_berechnen(&Loop)' CRC to charge
    Print "Daten="+Str $(&Loop)+"   CRC8="+Str $(CRC8_Sp%),
    CRC8_berechnen(  val( "%"+right$("00000000"+be$(&Loop),8)+right$("00000000"+be$(CRC8_Sp%),8) )  )
    Print tab(40);Str $(CRC8_Sp%)

EndWhile

waitinput