How to use crc16? about crcphp HOT 2 CLOSED

    $value = str_ireplace("0x", "", $value);
    $value = str_ireplace(" ", "", $value);
    
    if (ctype_xdigit($value) === false) {
        echo 'Wrong HEX-string';
        return;
    }

    $str = str_split($value, 2);

    $byte_array = array();
    foreach ($str as $s) {
        $temp = pack("H*", $s);
        $tt = unpack('C', $temp);
        $byte_array[] = $tt[1];
    }

if ($datatype === "ascii") {
    $data = str_split($value, 1);
    for ($i = 0; $i < count($data); $i++) {
        $byte_array[$i] = ord($data[$i]);
    }
} else {
    $value = str_ireplace("0x", "", $value);
    $value = str_ireplace(" ", "", $value);
    if (ctype_xdigit($value) === false) {
        echo 'Wrong HEX-string';
        return;
    }
    $str = str_split($value, 2);
    for ($i = 0; $i < count($str); $i++) {
        $byte_array[$i] = hexdec($str[$i]);
    }