Patent ID: 6055121
Filing Date: 2000-04-25
Classification: G11B

Abstract:
A method for selecting an optimal detection threshold used to identify addresses of tracks in a disc drive, the disc drive having a head controllably positionable adjacent a surface of a rotatable disc on which the tracks are defined, the method comprising steps of:(a) positioning the head over a selected track and generating a plurality of readback signals from track address fields associated with the selected track, the readback signals having baseline portions, peaks with positive polarity with respect to the baseline portions and peaks with negative polarity with respect to the baseline portions;(b) generating a first set of track address sequence signals through the comparison of selected readback signals to a first detection threshold, the first detection threshold having a selected magnitude and polarity with respect to the baseline portions;(c) accumulating a total count of erroneous track address sequence signals from the first set of track address sequence signals;(d) generating a second set of track address sequence signals through the comparison of selected readback signals to a second detection threshold, the second detection threshold having a different magnitude, but the same selected polarity, as the first detection threshold;(e) accumulating a total count of erroneous track address sequence signals from the second set of track address sequence signals; and(f) selecting the optimal detection threshold in relation to the total counts of erroneous track address sequence signals obtained using the first and second detection thresholds, the optimal detection threshold having the same selected polarity as the first and second detection thresholds.