Claims
- 1. A method of determining a signal level of a read signal in a disc drive generated by a transducer from data written on a track of a disc in the disc drive, the track having at least a first portion and a second portion, the method comprising steps of:
(a) obtaining a combined read signal level value indicative of a value of the read signal generated from a plurality of different portions of the track; and (b) performing a drive performance operation utilizing the combined read signal level value.
- 2. The method of claim 1 wherein the obtaining step (a) comprises:
(a1) providing the read signal corresponding to the first portion of the track to an automatic gain control (AGC) component; (a2) storing a first AGC output value from the AGC component that is indicative of a level of the read signal. (a3) providing the read signal corresponding to the second portion of the track to the AGC component; and (a4) combining a second AGC output value from the AGC component that is indicative of a level of the read signal corresponding to the second portion of the track with the first AGC output value to obtain a combined AGC output value; and
- 3. The method of claim 2 wherein the storing step (a2) comprises:
(a2.1) receiving a read gate signal for the first portion of the track; and (a2.2) storing the first AGC output value in response to receiving the read gate signal.
- 4. The method of claim 3 wherein the combining step (a4) comprises:
(a4.1) receiving a read gate signal for the second portion of the track; (a4.2) summing the first and second AGC output values in response to receiving (a4.1) to obtain a summed value; and (a4.3) storing the summed value.
- 5. The method of claim 4 wherein the combining step (a4) further comprises:
(a4.4) averaging the summed value over a number of read gate signals received for the track.
- 6. The method of claim 4 wherein the track includes a plurality of additional portions and further comprising:
prior to performing drive performance operation (b), for each of the additional portions;
(c) receiving a read gate signal; (d) summing the AGC output value associated with the given portion with the summed value in response to receiving (c) to obtain a new summed value; and (e) storing the new summed value.
- 7. The method of claim 6 and further comprising:
(f) averaging the new summed value over a total number of read gate signals received for the track to obtain the combined AGC output value.
- 8. The method of claim 1 wherein performing a drive performance operation (b) comprises:
(b1) performing a drive testing operation.
- 9. The method of claim 1 wherein performing a drive performance operation (b) comprises:
(b1) performing a drive turning operation.
- 10. The method of claim 6 and further comprising:
(f) prior to the summing step (d) determining whether the AGC value associated with the given portion deviates from one or more AGC values associated with other portions by a preselected threshold amount; and (g) if so, identifying the given portion as an aberrant portion.
- 11. The method of claim 10 and further comprising:
(h) proceeding without summing the AGC value associated with the aberrant portion with the summed value.
- 12. The method of claim 11 and further comprising:
(i) averaging the new summed value over a total number of read gate signals for the track, less those associated with aberrant portions, to obtain the combined AGC output value.
- 13. A method of performing a drive performance operation on a disc drive having a disc with a data track divided into sectors, comprising:
(a) reading data in the sectors on the track; (b) generating an automatic gain control (AGC) value indicative of a signal amplitude of the read signal; (c) calculating a representative AGC value over a plurality of the sectors; and (d) performing the drive performance operation based on the average AGC value.
- 14. The method of claim 13 wherein generating (b) comprises:
(b1) receiving a read gate signal corresponding to each of the sectors.
- 15. The method of claim 14 wherein generating (b) comprises:
(b2) in response to the read gate signals, storing the AGC value to obtain stored AGC values.
- 16. The method of claim 15 wherein calculating (c) comprises:
(c1) summing the stored AGC values to obtain a summed AGC value; and (c2) averaging the summed AGC value over a number of the sectors.
- 17. The method of claim 16 wherein summing (c1) comprises:
(c1.1) determining whether each stored AGC value deviates from one or more other AGC values by a preselected amount; (c1.2) if so, identifying a sector associated with the AGC value that deviates by the preselected amount as a deviant sector; and (c1.3) summing only the stored AGC values associated with sectors that are not deviant sectors.
- 18. The method of claim 13 wherein the drive performance operation comprises a drive tuning operation.
- 19. The method of claim 13 wherein the drive performance operation comprises a drive testing operation.
- 20. A disc drive, comprising:
a disc having a track; and means for determining an average signal amplitude read from the track.
- 21. The disc drive of claim 20 wherein the means for determining comprises:
means for averaging an automatic gain control value over a number of sectors on the track.
- 22. The disc drive of claim 20 wherein the means for determining comprises:
means for identifying aberrant portions of the track and excluding the aberrant portions from averaging.
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from U.S. Provisional Application No. 60/323,776 filed on Sep. 20, 2001 for inventors David Kok Leong Loh, Victor Weng Khin, Quek Leong Choo, Myint Ngwe and KahLiang Gan and entitled IMPLEMENTATION OF AVERAGE AUTOMATIC GAIN CONTROL (AGC) IN CHANNEL CHIP.
Provisional Applications (1)
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Number |
Date |
Country |
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60323776 |
Sep 2001 |
US |