Answer to Question #338318 in Combinatorics | Number Theory for Maneo

Question

with the aid of an example, explain how even and odd parity work and give an example application where they may be useful.

Answer 1

In computers, parity (from the Latin paritas, meaning equal or equivalent) is a technique that checks whether data has been lost or written over when it is moved from one place in storage to another or when it is transmitted between computers.Inrs.

How parity works

Because data transmission is not an entirely error-free process, data is not always received in the same way as it was transmitted. A parity bit adds checksums into data that enable the target device to determine whether the data was received correctly.

An additional binary digit, the parity bit, is added to a group of bits that are moved together. This bit, sometimes referred to as a check bit, is used only to identify whether the moved bits arrived successfully.

Even parity bit vs. odd parity bit

There are two kinds of parity bits:

In even parity, the number of bits with a value of one are counted. If that number is odd, the parity bit value is set to one to make the total number of ones in the set (including the parity bit) an even number. If the number of bits with a value of one is even, the parity bit value is set to zero, so that the total number of ones in the set (including the parity bit) remains an even number.

In odd parity, if the number of bits with a value of one is an even number, the parity bit value is set to one to make the total number of ones in the set (including the parity bit) an odd number. If the number of bits with a

value of one is odd, the parity bit value is set to zero, so that the total number of ones in the set (including the parity bit) remains an odd number.

At the receiving end, each group of incoming bits is checked to see if the group totals to an even or odd number. If a transmission error occurs, the transmission is retried or the system halts and an error message is sent to the user.