Intel
®
81341 and 81342—Application DMA Unit
Intel
®
81341 and 81342 I/O Processors
Developer’s Manual
December 2007
508
Order Number: 315037-002US
5.8.2
CRC-32C Algorithm
The CRC Engine generates a 32-bit CRC of the programmed data stream using the
CRC-32C generator polynomial required by the iSCSI* Specification, (1EDC6F41).
The incoming data stream is shifted and recirculated through the CRC polynomial using
a method similar to that illustrated in
Figure 70, “Calculation of 32-bit CRC for iSCSI
. The initial seed for this operation is required to be FFFF FFFFh which
is equivalent to the initial value of the CRC internal register in
Figure 69. CRC-32C Generator Polynomial
Figure 70. Calculation of 32-bit CRC for iSCSI PDU
1 + x
6
+ x
8
+ x
9
+ x
10
+ x
11
+ x
13
+ x
14
+ x
18
+ x
19
+ x
20
+ x
22
+ x
23
+ x
25
+ x
26
1
E
D
C
6
F
4
1
3
1
3
0
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
1
9
1
8
1
7
1
6
1
5
1
4
1
3
1
2
1
1
1
0
9
8
7
6
5
4
3
2
1
0
3
1
3
0
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
1
9
1
8
1
7
1
6
1
5
1
4
1
3
1
2
1
1
1
0
9
8
7
6
5
4
3
2
1
0
=
Fli
p
Flo
p
=
X
O
R
G
at
e
iS
C
S
I P
D
U
C
R
C
-3
2
C
PDU Byte 0
PDU Byte 1
PDU Byte 2
7 6 5 4 3 2 1 0
B
yt
e O
rd
er
B
it
O
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er
In
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t
B6235-01