paritytarkistuksissa

Paritytarkistus, known in English as parity check, is a simple error-detection method used in computing and digital communication. It involves adding an extra bit, called a parity bit, to a binary code word. The parity bit is set to either 0 or 1 to make the total number of '1' bits in the code word either even or odd, depending on the parity scheme being used.

There are two main types of parity checks: even parity and odd parity. In an even parity system, the parity bit is set so that the total count of '1's in the entire code word (including the parity bit) is an even number. If the original data has an odd number of '1's, the parity bit is set to '1'. If it has an even number of '1's, the parity bit is set to '0'. Conversely, in an odd parity system, the parity bit is set to ensure the total count of '1's is an odd number.

When the data is transmitted or stored, the parity bit is sent along with the data bits. At the receiving end, the parity is recalculated. If the recalculated parity matches the received parity bit, it is assumed that no error has occurred. If they do not match, it indicates that at least one bit error has occurred during transmission or storage.

Parity checks are very basic and can only detect a single-bit error. If two bits are flipped, the parity will remain correct, and the error will go undetected. For more robust error detection and correction, more sophisticated methods like Cyclic Redundancy Check (CRC) or Hamming codes are used. However, parity checks are simple to implement and can be effective in environments where the likelihood of single-bit errors is low.