Parity Check
Computer Science: Cambridge International GCSE, topic 1.2.4
Parity Bits
Check digits are extra digits that are appended to a number to confirm that the number has been transmitted or retrieved correctly.
Parity bit
- A parity bit is a simple check digit that is added to a binary number to help check that it has been received correctly.
- The value of the digit depends on whether an even or an odd parity system is in place.
Setting a parity bit
- The sender should add the parity bit to the number:
- In an even parity system, a digit should be added so that there is an even number of 1s in the number.
- In an odd parity system, a digit should be added so that there is an odd number of 1s in the number.
Receiving the data
- When receiving the data, the recipient can re-count the number of 1s to verify that the data is correct.
Test yourself on Parity Check
Sending Data Using Parity Bits
In an even parity system, you receive the binary number 10011000.
Is the number correct?