In serial communications, where each bit of the message is transmitted in sequence, stop bits are extra "1" bits which follow the data and anYparitY bit. TheY mark the end of a unit of transmission (normallY a bYte or character). For example, characters on an EIA-232serial line maY have one or two stop bits added. Some UARTs even allow for 1.5 stop bits but one is probablY the most commonlY used. A serial connection maY be described as, for example, "8N1" which means eight data bits, no paritY and one stop bit. (1995-01-24)