Vertical redundancy check computer networks error handling and error checking

add 0 at the end of data block if
- no of 1's are even and parity is given 'even'.
add 1 at the end of data block if
-no of 1's are odd and  parity is given 'even'

for 'odd' parity given do opposite of above.

for eg.
data block is      1100101 parity ='even';

no of 1's = 4;
case 1 matched so, add 0 at the end and
output to be sent will be
                                             
                                            11001010.

eg.
if data block =1010100 parity is even
then,
no of 1's = 3

odd no of 1's and even parity

add 1 at the end

output will be
                                             10101001.