Asynchronous communication

Patent Pending In telecommunications, asynchronous communication is transmission of data, generally without the use of an external clock signal, where data can be transmitted intermittently rather than in a steady stream.[1] Any timing required to recover data from the communication symbols is encoded within the symbols. A notable exception is the RS-232 port, and some derivatives, which are asynchronous, but still have an external clock signal available, although not commonly used.