Datasheet

5.8 ECC
A 40-byte three-interleaved ECC processor provides user data verification and correction capability. The
first four bytes of ECC are check bytes for user data and the other 36 bytes are Read Solomon ECC
bytes. Each interleave has 12 bytes for ECC. Hardware logic corrects up to 15 bytes (5 bytes for each
interleave) errors On-the-fly.
Following are examples of some error cases. "O" show that this byte contains no error. "X" shows that at
least one bit of this byte is bad.
On The Fly correctable
Byte # 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7
1 1 1 1 1 1 1 1
Interleave
A B C A B C A B C A B C A B C A B C
A
B
C
Error pattern
5
Error byte # for
each interleave
X X X X X X X X X X X X X X X O O O
Error pattern
5
5
5
5 5
X X X X X X X X X O O O X X X X X X
Uncorrectable
Byte # 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7
1 1 1 1 1 1 1 1
Interleave
A B C A B C A B C A B C A B C A B C
A
B
C
Error pattern
6
Error byte # for
each interleave
X X X X X X X X X X X X X X X X O O
Error pattern
6
5
5
0 0
X O O X O O X O O X O O X O O X O O
Figure 10. ECC
Hard disk drive specification for DSCM-11000/-10512/-10340
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