Parity: Difference between revisions
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'''Parity''' is a very early error-detectiion system (now mostly replaced by [[Cyclic redundancy check|CRCs]]). It can detect all one-bit errors, but only about half of all two-bit errors. | '''Parity''' is a very early error-detectiion system (now mostly replaced by [[Cyclic redundancy check|CRCs]]). It can detect all one-bit errors, but only about half of all two-bit errors. It can not correct errors. | ||
It consists of one extra [[bit]] per [[byte]]/[[word]]. On storage or transmission, the parity bit is set so that the total number of 'on' bits across the entire group is either even (so-called 'even parity') or odd ('odd parity'). When the data is read back or received, the parity is checked, to make sure that it is what is expected. | It consists of one extra [[bit]] per [[byte]]/[[word]]. On storage or transmission, the parity bit is set so that the total number of 'on' bits across the entire group is either even (so-called 'even parity') or odd ('odd parity'). When the data is read back or received, the parity is checked, to make sure that it is what is expected. | ||
==See also== | |||
* [[UNIBUS parity]] | |||
{{semi-stub}} | {{semi-stub}} | ||
[[Category: Computer Basics]] | |||
Latest revision as of 11:06, 2 November 2026
Parity is a very early error-detectiion system (now mostly replaced by CRCs). It can detect all one-bit errors, but only about half of all two-bit errors. It can not correct errors.
It consists of one extra bit per byte/word. On storage or transmission, the parity bit is set so that the total number of 'on' bits across the entire group is either even (so-called 'even parity') or odd ('odd parity'). When the data is read back or received, the parity is checked, to make sure that it is what is expected.
