def update(data)
      data.each_byte do |b|
        b = revert_byte(b) if REVERSE_DATA
        @crc = ((@table[((@crc >> 8) ^ b) & 0xff] ^ (@crc << 8)) & 0xffff)
      end

      return self
    end
def update(data)
      data.each_byte do |b|
        b = revert_byte(b) if REVERSE_DATA
        @crc = ((@table[((@crc >> 8) ^ b) & 0xff] ^ (@crc << 8)) & 0xffff)
      end

      return self
    end
Updates the CRC16 checksum.

 @param [String] data
   The data to update the checksum with.