Information Technology Reference
In-Depth Information
x
3
(
x
6
+
x
3
+
x
2
)
x
9
+
x
6
+
x
5
(1001100000)
Figure D.1 shows the operations at the transmitter. The transmitted message is 1001100001
and Figure D.2 shows the operations at the receiver. It can be seen that the remainder is zero,
so there have been no errors in the transmission.
1111101
1101 1001100000
1101
1001
1101
1000
1101
1010
1101
1110
1101
1100
1101
001
Figure D.1
CRC coding example
1111101
1101 1001100001
1101
1001
1101
1000
1101
1010
1101
1110
1101
1101
1101
000
Figure D.2
CRC decoding example
The CRC-CCITT is a standard polynomial for data communications systems and can detect:
•
All single and double bit errors.
•
All errors with an odd number of bit.
•
All burst errors of length 16 or less.
•
99.997% of 17-bit error bursts.
•
99.998% of 18-bit and longer bursts.
