Assuming that even parity has been received as 001001001. If it is not a correct code, check it.

To check if the received code 001001001 with even parity is correct, we need to follow these steps:

Step 1: Understand Parity Bits

Parity bits are a simple error-detection mechanism that allows the detection of single-bit errors in data transmission. With even parity, the number of 1s in the code, including the parity bit, must be even. If the count of 1s is odd, then there is an error.

Step 2: Count the Number of 1s

We need to count the number of 1s in the received code.

Received code: 001001001

Count of 1s: 3

Step 3: Determine if the Parity is Correct

Since we are dealing with even parity, the total count of 1s should be even. In this case, the count is 3, which is odd.

Step 4: Conclusion

Since the count of 1s is odd, the received code does not have the correct even parity. Therefore, we can conclude that there is an error in the received code.

Summary Table

Step	Action	Result
1	Understand parity bits	Even parity requires an even number of 1s
2	Count the number of 1s	There are 3 1s in the code
3	Determine if parity is correct	The count of 1s is odd (3), so parity is not correct
4	Conclusion	The received code 001001001 has an error

Example

Let's consider another example with even parity for clarity:

Suppose we receive the code 1101010. We would perform the following steps:

1. Count the number of 1s: There are 4 1s in the code.
2. Determine if the parity is correct: Since the count of 1s is even (4), the parity is correct for even parity.

In this example, the received code 1101010 would be considered correct if it uses even parity.