crc16

crc16.js

exports.crc16 = function (buffer, len) {
    var crc = 0xffff;
    for (var i = 0; i < len; i++) {
        crc = ((crc ^ buffer[i]) & 0x00ff) + (crc & 0xff00);
        for (var bit = 0; bit < 8; bit++) {
            if ((crc & 0x0001) === 0x0000) {
                crc >>= 1;
            }
            else {
                crc >>= 1;
                crc ^= 0xa001;
            }
        }
    }
    crc = ((crc & 0x00ff) << 8) + ((crc & 0xff00) >> 8);
    return(crc);
}