#cpp
//-----------------crc8()-------------------------

uint8 crc8(uint8*buf, uint8 data_byte)
   {
   uint8 crc=0x00;
   uint8 data_bit=0x80;
   
   while(data_byte>0)
      {
      if(((crc&0x01)!=0)!=((buf[data_byte]&data_bit)!=0))
         {
         crc>>=1;
         crc^=0xCD;
         }
      else crc>>=1;

      data_bit>>=1;
      
      if(!data_bit)
         {
         data_bit=0x80;
         data_byte--;
         }
      }
      return(crc);
   }

 for i = 0 to UBound(buf)
     'if (((crc and 1) <> 0) <> ((buf(i) and data_bit) <> 0)) Then
     if (((crc and 1) <> 0) <> ((Chr("&h" & buf(i)) and data_bit) <> 0)) Then
        crc = crc >> 1
        crc = crc Xor 205
     else
         crc = crc >> 1
     End If 
 
     data_bit = data_bit >> 1
 
     if (data_bit <> 0) Then 
     
     else
         data_bit = 128
         i = i - 1
     End If  
 next
 sys.onRes crc
End Sub