ho trovato in rete un po di esempi anche se tutte "Procedure"

problema:

ho una serie di byte dei quali calcolare il relativo CRC16
una volta calcolato devo inserire i due byte in una posizione definita

mi servirebbe, data una certa stringa (stringa perchè mi risulta più
facile in base alle mie conoscenze attuali di delphi... praticamente
stringa composta dai codici ASCII dey bytes in questione), di
calcolarne il CRC16

secondo me dovrei fare una function e non una procedure ... qualche
help ???

implementation

procedure CalcCRC16(p: pointer; n: integer; var crc16: word);
const
crc16table: array[0..255] of word = (
$0000, $c0c1, $c181, $0140, $c301, $03c0, $0280, $c241,
$c601, $06c0, $0780, $c741, $0500, $c5c1, $c481, $0440,
$cc01, $0cc0, $0d80, $cd41, $0f00, $cfc1, $ce81, $0e40,
$0a00, $cac1, $cb81, $0b40, $c901, $09c0, $0880, $c841,
$d801, $18c0, $1980, $d941, $1b00, $dbc1, $da81, $1a40,
$1e00, $dec1, $df81, $1f40, $dd01, $1dc0, $1c80, $dc41,
$1400, $d4c1, $d581, $1540, $d701, $17c0, $1680, $d641,
$d201, $12c0, $1380, $d341, $1100, $d1c1, $d081, $1040,
$f001, $30c0, $3180, $f141, $3300, $f3c1, $f281, $3240,
$3600, $f6c1, $f781, $3740, $f501, $35c0, $3480, $f441,
$3c00, $fcc1, $fd81, $3d40, $ff01, $3fc0, $3e80, $fe41,
$fa01, $3ac0, $3b80, $fb41, $3900, $f9c1, $f881, $3840,
$2800, $e8c1, $e981, $2940, $eb01, $2bc0, $2a80, $ea41,
$ee01, $2ec0, $2f80, $ef41, $2d00, $edc1, $ec81, $2c40,
$e401, $24c0, $2580, $e541, $2700, $e7c1, $e681, $2640,
$2200, $e2c1, $e381, $2340, $e101, $21c0, $2080, $e041,
$a001, $60c0, $6180, $a141, $6300, $a3c1, $a281, $6240,
$6600, $a6c1, $a781, $6740, $a501, $65c0, $6480, $a441,
$6c00, $acc1, $ad81, $6d40, $af01, $6fc0, $6e80, $ae41,
$aa01, $6ac0, $6b80, $ab41, $6900, $a9c1, $a881, $6840,
$7800, $b8c1, $b981, $7940, $bb01, $7bc0, $7a80, $ba41,
$be01, $7ec0, $7f80, $bf41, $7d00, $bdc1, $bc81, $7c40,
$b401, $74c0, $7580, $b541, $7700, $b7c1, $b681, $7640,
$7200, $b2c1, $b381, $7340, $b101, $71c0, $7080, $b041,
$5000, $90c1, $9181, $5140, $9301, $53c0, $5280, $9241,
$9601, $56c0, $5780, $9741, $5500, $95c1, $9481, $5440,
$9c01, $5cc0, $5d80, $9d41, $5f00, $9fc1, $9e81, $5e40,
$5a00, $9ac1, $9b81, $5b40, $9901, $59c0, $5880, $9841,
$8801, $48c0, $4980, $8941, $4b00, $8bc1, $8a81, $4a40,
$4e00, $8ec1, $8f81, $4f40, $8d01, $4dc0, $4c80, $8c41,
$4400, $84c1, $8581, $4540, $8701, $47c0, $4680, $8641,
$8201, $42c0, $4380, $8341, $4100, $81c1, $8081, $4040
);
type
buffer = array[0..0] of byte;
var
i: integer;
q: ^buffer;
begin
q := p;
for i := 0 to n-1 do
crc16 := hi(crc16) xor crc16table[ q^[i] xor lo(crc16) ];
end;

end.