Parity Bit

• Parity Bit or Check Bit, is a single bit added to a string of binary code that indicates whether the number of 1-bits in the string is even or odd.
• Parity bits are used as the simplest form of error detecting code.

Types of Parity Bit:

There are two types of parity bits are there. Which are:

• Even Parity Bit
• Odd Parity Bit

Even Parity Bit:

• The count of number of 1's in total data bit is even then the parity bit is set as "0".
• The count of number of 1's in total data bit is odd then the parity bit is set as "1".

Odd Parity Bit:

• The count of number of 1's in total data bit is even then the parity bit is set as "1".
• The count of number of 1's in total data bit is odd then the parity bit is set as "0".

Need of Parity Bit:

• The Parity bit is used in parity error checking to find the errors that may occur during data transmission.
• Parity bits are often used in data transmission to ensure that data is not corrupted during the transfer process.

For example, 

• Every 7 bits of data may include a parity bit (for a total of 8 bits, or one byte). 
• If the data transmission protocol is set to an odd parity, each data packet must have an odd parity. If it is set to even, each packet must have an even parity. 
• If a packet is received with the wrong parity, an error will be produced and the data will need to be re-transmitted.

Parity Bit Checking Process: