Consider the following message M = 1010001101. The cyclic redundancy check (CRC) for this message using the divisor polynomial x5 + x4 + x2 + 1 is :
M = 1010001101 Divisor polynomial: 1.x5 +1.x4+0.x3+1.x2+0.x2+1.x0 Divisor polynomial bit= 110101 Bits to be appended to message= (divisor polynomial bits – 1) = 5 Append 5 zeros to message bits, modified message: 101000110100000
Now, divide and XOR the message with divisor polynomial bits. Make resultant reminder to 5 bit again and that is the CRC send along with the message.
This explanation has been contributed by Sandeep Pandey.
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