Data storage device employing variable size interleave written track segments
View Patent ↗A data storage device is disclosed comprising a head actuated over a disk comprising a plurality of data tracks. Data is encoded into a first number of codewords, and the first number of codewords are interleave written to a first segment of a first data track. Data is encoded into a second number of codewords, and the second number of codewords are interleave written to a second segment of the first data track. The first number of codewords is different than the second number of codewords, and a size of the first segment is different than a size of the second segment.
1. A data storage device comprising:
a disk comprising a plurality of data tracks;
a head; and
control circuitry configured to:
encode data into a first number of codewords;
interleave write the first number of codewords to a first segment of a first data track;
encode data into a second number of codewords; and
interleave write the second number of codewords to a second segment of the first data track;
wherein the first number is different than the second number and a size of the first segment is different than a size of the second segment.
2. The data storage device as recited in claim 1 , wherein:
the first data track comprises an integer number N sect of data sectors;
the first segment comprises a first integer L 0 of the data sectors; and
the second segment comprises a second integer L 1 of the data sectors.
3. The data storage device as recited in claim 2 , wherein the second segment comprises one less data sector than the first segment.
4. The data storage device as recited in claim 3 , wherein the control circuitry is further configured to compute L 0 according to:
L
0
=
L
targ
-
⌊
(
L
targ
-
(
N
sect
mod
L
targ
)
)
mod
L
targ
⌈
N
sect
L
targ
⌉
⌋
where L targ represents a target number of data sectors for the first segment.
5. The data storage device as recited in claim 4 , wherein the first data track comprises an integer N L0 of the first segments and an integer N L1 of the second where:
N
L
1
=
(
(
L
targ
-
(
N
sect
mod
L
targ
)
)
mod
L
targ
)
mod
⌈
N
sect
L
targ
⌉
N
L
0
=
⌈
N
sect
L
targ
⌉
-
N
L
1
.
6. The data storage device as recited in claim 5 , wherein the control circuitry is further configured to compute L 0 , N L0 and N L1 on the fly when executing a write command.
7. The data storage device as recited in claim 5 , wherein the control circuitry is further configured to compute L 0 , N L0 and N L1 on the fly when executing a read command.
8. A method of operating a data storage device, the method comprising:
encoding data into a first number of codewords;
interleave writing the first number of codewords to a first segment of a first data track on a disk;
encoding data into a second number of codewords; and
interleave writing the second number of codewords to a second segment of the first data track on the disk;
wherein the first number is different than the second number and a size of the first segment is different than a size of the second segment.
9. The method as recited in claim 8 , wherein:
the first data track comprises an integer number N sect of data sectors;
the first segment comprises a first integer L 0 of the data sectors; and
the second segment comprises a second integer L 1 of the data sectors.
10. The method as recited in claim 9 , wherein the second segment comprises one less data sector than the first segment.
11. The method as recited in claim 10 , further comprising computing L 0 according to:
L
0
=
L
targ
-
⌊
(
L
targ
-
(
N
sect
mod
L
targ
)
)
mod
L
targ
⌈
N
sect
L
targ
⌉
⌋
where L targ represents a target number of data sectors for the first segment.
12. The method as recited in claim 11 , wherein the first data track comprises an integer N L0 of the first segments and an integer N L1 of the second segments where:
N
L
1
=
(
(
L
targ
-
(
N
sect
mod
L
targ
)
)
mod
L
targ
)
mod
⌈
N
sect
L
targ
⌉
N
L
0
=
⌈
N
sect
L
targ
⌉
-
N
L
1
.
13. The method as recited in claim 12 , further comprising computing L 0 , N L0 and N L1 on the fly when executing a write command.
14. The method as recited in claim 12 , further comprising computing L 0 , N L0 and N L1 on the fly when executing a read command.