Method for precompensation/write-current latching to improve error rate
View Patent ↗A method is presented for writing data to a surface of a magnetic disk in a disk drive. The method includes determining a number of sector groups into which sectors of the data to be written will be grouped, loading registers with current values, kick-latching values, and precompensation values for each of said sector groups, and applying the current values, kick-latching values, and precompensation values for each of the sector groups to the write head while writing data to the sector groups of the recording media.
1. A method for controlling current supplied to a write head during writing operations in a device including memory registers, the method comprising:
A) determining a number of sector groups into which sectors of the data to be written will be grouped;
B) loading to said memory registers a predetermined current value for each of said number of sector groups;
C) loading to said memory registers a predetermined kick-latching value for each of said number of sector groups;
D) loading to said memory registers a predetermined precompensation value for each of said number of sector groups;
E) applying the first predetermined current, first predetermined kick-latching and first predetermined precompensation values of current to the sectors of the first sector group; and
F) applying the next predetermined current, next predetermined kick-latching and next predetermined precompensation values of current to the sectors of the next sector group until the predetermined cuffent, predetermined kick-latching and predetermined precompensation values of current of the last sector group has been completed.
2. The method of claim 1 , wherein:
said memory registers include preamplifier registers and B) includes loading values to said preamplifier registers.
3. The method of claim 2 , wherein the last sector group is addressed in a time frame between 0.5 msec and 1 msec from the first sector group.
4. The method of claim 1 , wherein:
said memory registers include preamplifier registers, and C) includes loading values to said preamplifier registers.
5. The method of claim 1 , wherein:
said memory registers include channel registers, and D) includes loading values to said channel registers.
6. The method of claim 1 , wherein:
at least one of said precompensation values is negative.
7. The method of claim 1 , wherein:
at least one of said precompensation values is positive.
8. The method of claim 1 , wherein:
said precompensation value of the last sector group is zero.
9. The method of claim 1 , wherein:
said precompensation value of the last sector group is positive.
10. A method for writing data to a surface of a magnetic disk in a disk drive having a write head, the method comprising:
A) determining a number of sector groups into which sectors of the data to be written will be grouped;
B) setting current values, kick-latching values, and precompensation values for each of said sector groups;
C) applying said current values, kick-latching values, and precompensation values to said writing head while writing data to data locations within each of said sector groups;
D) performing a sector count to produce sector count criteria; and
E) adjusting said precompensation values in accordance with said sector count criteria.
11. The method of claim 10 , wherein:
at least one of said precompensation values is negative.
12. The method of claim 10 , wherein:
at least one of said precompensation values is positive.
13. The method of claim 10 , wherein:
said sector groups include a last sector group and said precompensation value of said last sector group is zero.
14. The method of claim 10 , wherein:
said sector groups include a last sector group and said precompensation value of said last sector group is positive.
15. The method of claim 10 , wherein the last of the sector groups is addressed in a time frame between 0.5 msec and 1 msec from the first of the sector groups.
16. A method for writing data to a surface of a magnetic disk in a disk drive having a write head, the method comprising:
A) grouping a number of sectors into sector groups designated N O . . . N N ; which data is to be written;
B) determining current value I O . . . I N , kick-latching values k O . . . k N , and precompensation values p O . . . p N for each of said sector groups N O . . . N N ;
i) performing a sector count to produce sector count criteria, and adjusting said precompensation values p O . . . p N ; in accordance with said sector count criteria;
C)applying said current value I O , kick-latching values k O , and precompensation value p O to said write head while writing to sector group N O ; and
D) applying said next current value I, kick-latching value k and precompensation value p to said write head while writing the next sector group N until all current values I N , kick-latching values k N and precompensation values p N have been applied to said write head while writing to sector group N N .
17. The method of claim 16 , wherein:
at least one of said precompensation values is negative.
18. The method of claim 16 , wherein:
at least one of said precompensation values is positive.
19. The method of claim 16 , wherein:
said precompensation value of said last sector group N N is zero.
20. The method of claim 16 , wherein:
said precompensation value of said last sector group N N is positive.
21. The method of claim 16 , wherein:
the last sector group N N is addressed in a time frame between 0.5 msec and 1 msec from the first sector group N O .
22. A method for adjusting precompensation values in response to non-linear transition shifts (NLTS) in writing data to a surface of a magnetic disk in a disk drive having a write head, the method comprising:
A) grouping a number of sectors into sector groups designated N O . . . N N into which data is to be written;
B) loading a register with current values I O . . . I N , kick-latching values k O . . . k N , and precompensation values p O . . . p N for each of said sector groups N O . . . N N , wherein said precompensation values p O . . . p N are adjusted in accordance with said sector groups N O . . . N N ;
C) applying said current value I O , kick-latching values k O , and precompensation value p O to said write head while writing sector group No; and
D) applying said next current value I, kick-latching value k and precompensation value p to said write head while writing to the next sector group N until all current values I N , kick-latching values k N and precompensation values p N have been applied to said write head while writing to sector group N N .
23. The method of claim 22 , wherein the precompensation value p N is zero.
24. The method of claim 22 , wherein the precompensation value p N is positive.
25. The method of claim 22 , wherein:
at least one of said precompensation values is negative.
26. The method of claim 22 , wherein:
at least one of said precompensation values is positive.
27. The method of claim 22 , wherein the last sector group N N is addressed in a time frame between 0.5 msec and 1 msec from the first sector group N O .