8-N-1 is a common shorthand notation for a
serial port
In computing, a serial port is a serial communication interface through which information transfers in or out sequentially one bit at a time. This is in contrast to a parallel port, which communicates multiple bits simultaneously in parallel. ...
parameter setting or
configuration in
asynchronous mode, in which there is one start bit, eight (8)
data bits, no (N)
parity bit
A parity bit, or check bit, is a bit added to a string of binary code. Parity bits are a simple form of error detecting code. Parity bits are generally applied to the smallest units of a communication protocol, typically 8-bit octets (bytes) ...
, and one (1)
stop bit
Asynchronous serial communication is a form of serial communication in which the communicating endpoints' interfaces are not continuously synchronized by a common clock signal. Instead of a common synchronization signal, the data stream contai ...
.
As such, 8-N-1 is the most common configuration for
PC serial communications today.
The abbreviation is usually given together with the line speed in
bits per second
In telecommunications and computing, bit rate (bitrate or as a variable ''R'') is the number of bits that are conveyed or processed per unit of time.
The bit rate is expressed in the unit bit per second (symbol: bit/s), often in conjunction w ...
, as in 9600–8-N-1. The speed includes bits for
framing (stop bits, parity, etc.) and the effective data rate is lower than the bit transmission rate. For 8-N-1 encoding, only 80% of the bits are available for data (for every eight bits of data, ten bits are sent over the serial link — one start bit, the eight data bits, and the one stop bit).
References
{{Reflist
Serial buses
Data transmission