Seagate Technology Incorporated

John Edward Young

Alfredo Gay Sam

Nikki M Bruner

Method and apparatus for evaluating different digital data channel configurations. A digital data channel stores input data to a recordable medium and retrieves readback data from the medium. The input data are arranged into an input sequence of symbols of selected symbol length, and the readback data are arranged into an output sequence of symbols of the selected symbol length. Comparing the output sequence to the input sequence allows identification of the number of erroneous symbols for the selected symbol length. Different input and output sequences are generated using different symbol lengths from the same input and output data. In this way, error rate performance can be predicted for different error correction code (ECC) and run length limited (RLL) encoding scheme combinations. The steps are carried out by an emulation system preferably comprising a field programmable gate array (FPGA) which inhibits and emulates selected portions of the digital data channel.

Emulation system for evaluating digital data channel configurations

A method for optimizing logical track to physical track offset compensation of a data storage device includes steps of: associating each of a plurality of logical tracks to one of a plurality of physical tracks, selecting a set of sample tracks from the plurality of physical tracks, measuring an offset value for each logical track associated with one of the sample tracks, deriving, through an extrapolation technique, an offset compensation value for use with each of the sample tracks absent an association with one of the logical tracks, linking each measured offset compensation value and each estimated offset compensation value with its associated physical track, calculating, through an interpolation technique, an offset compensation value for use with each of the physical tracks absent an association with one of the sample tracks.

Optimizing reader to writer offset compensation for a disc drive

Method and apparatus for improving disc drive performance by reducing areal data storage density while maintaining data storage capacity. A total user data storage capacity is selected for a disc recording surface. A total number of user data fields is selected to meet the data storage capacity. The data fields are distributed among a plurality of concentric zones, each zone having a plurality of data tracks, each data track in each zone having a common number of data fields written at a first write frequency. The zones are defined in relation to a data density profile defining a desired data density relationship across the disc recording surface. A final write frequency is selected for each zone equal to or less than the first write frequency that will achieve the selected data storage capacity of each track in said zone, thereby reducing data density of at least selected tracks.

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Norman, OK, United States of America

John Edward Young