Cyclic Redundancy Check

Im trying to understand CRC and I'm getting confused as how to calculate the 'divisor'.

plz explain with example

6Comments
Sumit Verma @sumitkgp
13 Jan 2017 01:19 am
karmjit joshi @karmjitjoshi
13 Jan 2017 11:24 pm

The message 11001001 is to be transmitted using the CRC polynomial x^3 + 1 to protect it from errors.

how to calculate CRC polynomial x^3 + 1

Shraddha @shraddhagami
14 Jan 2017 06:55 pm

x3+1=1001

11001001000(Add 0's=>no.of bits in divisor-1)

1001 | 11001001000 |

            1001

            ------

            01011

              1001

                -------

               001000

                    1001

                     ---------

                    0001100

                           1001

                            -------

                              1010

                              1001

                              -------

                              0011

                   

 

CRC=11001001011

karmjit joshi @karmjitjoshi
14 Jan 2017 06:16 pm
hwz its x3+1=1001?
Shraddha @shraddhagami
14 Jan 2017 07:02 pm

X3=1

X2=0

X1=0

X0=1

If power of X is exist then 1 else 0

karmjit joshi @karmjitjoshi
14 Jan 2017 09:32 pm

thx for explanation shraddhagami.