Data storage device aborting write operation based on accumulated track squeeze metric for adjacent data track
View Patent ↗A data storage device is disclosed comprising a head actuated over a disk comprising a plurality of data tracks, including consecutive data tracks N−1 and N. A first write to data track N is performed using a first position error signal (PES) representing a position of the head relative to the data tracks. A track squeeze metric is generated for data track N−1 based on at least the first PES of the first write. The track squeeze metric for data track N−1 is accumulated during the first write, and the first write is aborted when the accumulated track squeeze metric for data track N−1 exceeds a first threshold.
1. A data storage device comprising:
a disk comprising a plurality of data tracks, including consecutive data tracks N−1 and N;
a head actuated over the disk; and
control circuitry configured to:
first write to data track N using a first position error signal (PES) representing a position of the head relative to the data tracks;
generate a track squeeze metric for data track N−1 based on at least the first PES of the first write;
accumulate the track squeeze metric for data track N−1 during the first write; and
abort the first write when the accumulated track squeeze metric for data track N−1 exceeds a first threshold.
2. The data storage device as recited in claim 1 , wherein the track squeeze metric is based on the first PES exceeding a second threshold toward data track N−1.
3. The data storage device as recited in claim 1 , wherein the track squeeze metric comprises a degree of track squeeze for data track N−1 based on the first PES during the first write and a second PES during a second write to data track N−1.
4. The data storage device as recited in claim 1 , wherein the data tracks include consecutive data tracks N−1, N, and N+1, and the control circuitry is further configured to:
generate a track squeeze metric for data track N+1 based on the first PES of the first write;
accumulate the track squeeze metric for data track N+1 during the first write; and
abort the first write when the accumulated track squeeze metric for data track N+1 exceeds the first threshold.
5. The data storage device as recited in claim 1 , wherein after the first write the control circuitry is further configured to:
store the accumulated track squeeze metric for data track N−1 in a non-volatile memory;
read the accumulated track squeeze metric for data track N−1 from the non-volatile memory; and
update the accumulated track squeeze metric for data track N−1 during a second write to data track N.
6. The data storage device as recited in claim 1 , wherein data track N−1 comprises a plurality of data sectors and the control circuitry is further configured to:
generate a track level redundancy over at least two of the data sectors in data track N−1; and
generate the track squeeze metric for data track N−1 during the first write based on the first PES of the first write and a correction power of the track level redundancy.
7. The data storage device as recited in claim 1 , wherein data track N−1 comprises a plurality of data sectors and the control circuitry is further configured to:
generate a track level redundancy over at least two of the data sectors in data track N−1;
after aborting the first write, read the at least two data sectors in data track N−1 and perform a first data recover of the data sectors without using the track level redundancy; and
when the first data recovery succeeds, decrease the accumulated value of the track squeeze metric for data track N−1 and continue the first write to data track N.
8. The data storage device as recited in claim 7 , wherein when the first data recovery fails, the control circuitry is further configured to:
perform a second data recovery of the at least two data sectors in data track N−1 using the track level redundancy; and
when the second data recovery succeeds:
relocate at least one of the data sectors in data track N−1; and
continue the first write to data track N.
9. The data storage device as recited in claim 7 , wherein when the first data recovery fails, the control circuitry is further configured to:
perform a second data recovery of the at least two data sectors in data track N−1 using the track level redundancy; and
when the second data recovery succeeds:
rewrite at least one of the data sectors in data track N−1; and
continue the first write to data track N.
10. The data storage device as recited in claim 7 , wherein when the first data recovery fails, the control circuitry is further configured to:
perform a second data recovery of the at least two data sectors in data track N−1 using the track level redundancy; and
when the second data recovery succeeds:
continue the first write to data track N; and
after the first write to data track N, verify the data sectors in data track N−1 are recoverable.
11. The data storage device as recited in claim 10 , wherein when the verify fails, the control circuitry is further configured to relocate at least one of the data sectors in data track N−1.
12. A data storage device comprising:
a disk comprising a plurality of data tracks, including consecutive data tracks N−1 and N;
a head actuated over the disk; and
control circuitry configured to:
first write to data track N−1 using a first position error signal (PES) representing a position of the head relative to the disk;
second write to data track N using a second PES;
generate a track squeeze metric for data track N−1 based on at least the first PES of the first write and the second PES of the second write;
accumulate the track squeeze metric for data track N−1 during the second write; and
abort the second write when the accumulated track squeeze metric for data track N−1 exceeds a first threshold.
13. The data storage device as recited in claim 12 , wherein the data tracks include consecutive data tracks N−1, N, and N+1, and the control circuitry is further configured to:
prior to the second write, third write to data track N+1 using a third PES;
generate a track squeeze metric for data track N+1 based on the second PES of the second write and the third PES of the third write;
accumulate the track squeeze metric for data track N+1 during the second write; and
abort the second write when the accumulated track squeeze metric for data track N+1 exceeds the first threshold.
14. The data storage device as recited in claim 12 , wherein after the first write the control circuitry is further configured to:
store the accumulated track squeeze metric for data track N−1 in a non-volatile memory;
read the accumulated track squeeze metric for data track N−1 from the non-volatile memory; and
update the accumulated track squeeze metric for data track N−1 during a second write to data track N.
15. The data storage device as recited in claim 12 , wherein data track N−1 comprises a plurality of data sectors and the control circuitry is further configured to:
generate a track level redundancy over at least two of the data sectors in data track N−1; and
generate the track squeeze metric for data track N−1 during the first write based on the first PES of the first write, the second PES of the second write, and a correction power of the track level redundancy.
16. The data storage device as recited in claim 12 , wherein data track N−1 comprises a plurality of data sectors and the control circuitry is further configured to:
generate a track level redundancy over at least two of the data sectors in data track N−1;
after aborting the second write, read the at least two data sectors in data track N−1 and perform a first data recover of the data sectors without using the track level redundancy; and
when the first data recovery succeeds, decrease the accumulated value of the track squeeze metric for data track N−1 and continue the second write to data track N.
17. The data storage device as recited in claim 16 , wherein when the first data recovery fails, the control circuitry is further configured to:
perform a second data recovery of the at least two data sectors in data track N−1 using the track level redundancy; and
when the second data recovery succeeds:
relocate at least one of the data sectors in data track N−1; and
continue the second write to data track N.
18. The data storage device as recited in claim 16 , wherein when the first data recovery fails, the control circuitry is further configured to:
perform a second data recovery of the at least two data sectors in data track N−1 using the track level redundancy; and
when the second data recovery succeeds:
rewrite at least one of the data sectors in data track N−1; and
continue the first write to data track N.
19. The data storage device as recited in claim 16 , wherein when the first data recovery fails, the control circuitry is further configured to:
perform a second data recovery of the at least two data sectors in data track N−1 using the track level redundancy; and
when the second data recovery succeeds:
continue the first write to data track N; and
after the first write to data track N, verify the data sectors in data track N−1 are recoverable.
20. A data storage device comprising:
a disk comprising a plurality of data tracks, including consecutive data tracks N−1 and N;
a head actuated over the disk;
a means for first writing to data track N using a first position error signal (PES) representing a position of the head relative to the data tracks;
a means for generating a track squeeze metric for data track N−1 based on at least the first PES of the first writing;
a means for accumulating the track squeeze metric for data track N−1 during the first writing;
a means for storing in a non-volatile memory the accumulated track squeeze metric for data track N−1 generated during the first writing; and
a means for reading the accumulated track squeeze metric from the non-volatile memory and updating the accumulated track squeeze metric during a second writing to data track N.