Paritätsinformationen

Paritätsinformationen, often referred to as parity bits, are a simple form of error detection used in digital communication and data storage. The fundamental principle is to add an extra bit to a block of data such that the total number of '1' bits in the block (including the parity bit) is either always even (even parity) or always odd (odd parity).

To implement even parity, if the original data has an even number of '1' bits, the parity bit is set to '0'. If the original data has an odd number of '1' bits, the parity bit is set to '1'. For odd parity, the logic is reversed. During transmission or storage, the receiver performs the same parity calculation. If the calculated parity matches the received parity bit, it is assumed that the data has been transmitted or stored without error. If there is a mismatch, an error is detected.

Parity information is effective at detecting single-bit errors. However, it cannot detect errors where an even number of bits are flipped (e.g., two bits are flipped). This limitation means that parity is a basic error detection mechanism and is often supplemented by more robust error correction codes in critical applications. Despite its simplicity, parity is still used in some contexts, such as serial communication protocols and some older memory systems, due to its low overhead and ease of implementation.