Data storage device employing dynamic track trajectories
A data storage device is disclosed comprising a head actuated over a disk comprising servo data for defining a plurality of data tracks, including consecutive data tracks N−1, N, and N+1. Data is written to data track N using a position error signal (PES) generated by reading the servo data, and a read track trajectory for data track N is generated based on the PES of the write. Data is read from data track N based on the read track trajectory for data track N.
1. A data storage device comprising:
a disk comprising servo data for defining a plurality of data tracks, including consecutive data tracks N−1, N, and N+1;
a head actuated over the disk; and
control circuitry configured to:
first write to data track N using a first position error signal (PES) generated by reading the servo data, wherein the first PES is generated relative to a write track trajectory for data track N;
generate a read track trajectory for data track N based on the first PES of the first write, wherein the read track trajectory is different than the write track trajectory; and
read from data track N based on the read track trajectory for data track N.
2. The data storage device as recited in claim 1 , wherein the control circuitry is further configured to generate a write track trajectory for data track N−1 and data track N+1 based on the first PES of the first write.
3. The data storage device as recited in claim 1 , wherein the control circuitry is further configured to:
second write to data track N+1 using a second PES generated by reading the servo data;
update the read track trajectory for data track N based on the first PES of the first write and the second PES of the second write; and
read from data track N based on the updated read track trajectory for data track N.
4. The data storage device as recited in claim 3 , wherein the control circuitry is further configured to update the read track trajectory for data track N based on an average of the first PES of the first write and the second PES of the second write.
5. The data storage device as recited in claim 3 , wherein the control circuitry is further configured to:
generate a write track trajectory for data track N based on the second PES of the second write; and
write to data track N based on the write track trajectory for data track N.
6. The data storage device as recited in claim 3 , wherein the control circuitry is further configured to:
third write to data track N−1 using a third PES generated by reading the servo data;
update the read track trajectory for data track N based on the second PES of the second write and the third PES of the third write; and
read from data track N based on the updated read track trajectory for data track N.
7. The data storage device as recited in claim 6 , wherein the control circuitry is further configured to update the read track trajectory for data track N based on an average of the second PES of the second write and the third PES of the third write.
8. The data storage device as recited in claim 5 , wherein the control circuitry is further configured to:
third write to data track N−1 using a third PES generated by reading the servo data;
update the write track trajectory for data track N based on the second PES of the second write and the third PES of the third write; and
write to data track N based on the updated write track trajectory for data track N.
9. The data storage device as recited in claim 8 , wherein the control circuitry is further configured to update the read track trajectory for data track N based on the second PES of the second write and the third PES of the third write such that the read track trajectory for data track N is the same as the write track trajectory for data track N.
10. The data storage device as recited in claim 9 , wherein the control circuitry is further configured to update the write track trajectory for data track N based on an average of the second PES of the second write and the third PES of the third write.
11. The data storage device as recited in claim 9 , wherein the control circuitry is further configured to:
fourth write to data track N using a fourth PES generated by reading the servo data; and
update the read track trajectory for data track N based on the fourth PES of the fourth write such that the read track trajectory for data track N is different from the write track trajectory for data track N.
12. The data storage device as recited in 11 , wherein the control circuitry is further configured to update the write track trajectory for data track N−1 and data track N+1 based on the fourth PES of the fourth write.
13. A data storage device comprising:
a disk comprising servo data for defining a plurality of data tracks, including consecutive data tracks N−1, N, and N+1;
a head actuated over the disk; and
control circuitry configured to:
define a plurality of refresh zones on the disk, including a first refresh zone comprising data tracks N−1, N, and N+1;
update a dynamic track trajectory for data track N based on writing data track N−1 or data track N+1;
access data track N based on the dynamic track trajectory for data track N;
refresh the first refresh zone; and
zero the dynamic track trajectory for data track N in connection with refreshing the first refresh zone.
14. The data storage device as recited in claim 13 , wherein the dynamic track trajectory for data track N comprises a dynamic write track trajectory for data track N and a dynamic read track trajectory for data track N.
15. The data storage device as recited in claim 14 , wherein when refreshing the first refresh zone the control circuitry is further configured to:
first write to data track N−1 using a first position error signal (PES) generated by reading the servo data; and
update the zeroed dynamic write track trajectory for data track N based on the first PES of the first write.
16. The data storage device as recited in claim 15 , wherein when refreshing the first refresh zone the control circuitry is further configured to:
second write to data track N using a second PES generated by reading the servo data; and
update the zeroed dynamic read track trajectory for data track N based on the first PES of the first write and the second PES of the second write.
17. The data storage device as recited in claim 16 , wherein when refreshing the first refresh zone the control circuitry is further configured to:
third write to data track N+1 using a third PES generated by reading the servo data; and
update the dynamic write track trajectory and the dynamic read track trajectory for data track N based on the second PES of the second write and the third PES of the third write.
18. The data storage device as recited in claim 13 , wherein prior to refreshing the first refresh zone, the control circuitry is further configured to relocate data stored in data track N due to a squeeze of data track N.
19. The data storage device as recited in claim 18 , wherein when refreshing the first refresh zone, the control circuitry is further configured to write the relocated data to the first refresh zone.
20. A data storage device comprising:
a disk comprising servo data for defining a plurality of data tracks, including consecutive data tracks N−1, N, and N+1;
a head actuated over the disk;
a means for first writing to data track N using a first position error signal (PES) generated by reading the servo data, wherein the first PES is generated relative to a write track trajectory for data track N;
a means for generating a read track trajectory for data track N based on the first PES of the first write, wherein the read track trajectory is different than the write track trajectory; and
a means for reading from data track N based on the read track trajectory for data track N.