Seagate Technology Incorporated

Other

UttHeng Kan

Edmun ChianSong Seng

Xiong Liu

AikChuan Lim

Det Hau Wu

Lin Nah Lim

Jimmy Pang

KianKeong Ooi

Qiang Bi

BengWee Quak

WingKong Chiang

WeiMing Yeow

KayHee Tang

Stephen KowChiew Kuan

Ricardo SoonLian Lim

TaiVie Chiang

DetHau Wu

LinNah Lim

MingZhong Ding

Stanton MacDonough Keeler

ChoonKiat Lim

Joseph Cheng-Tsu Liu

WeiLoon Ng

KokHoe Chia

Bin Liu

Patrick TaiHeng Wong

Aik Chuan Lim

Djohni Chandra

Curtis Michael Pleiss

Edmun Chian Song Seng

Kay Hee Tang

Victor WengKhin Chew

Jeffrey Soon Beng Sim

Edmund ChianSong Seng

Patrick TaiHeng

NanLing Goh

MingZhong Dong

Det Hua Wu

Hon Yeong Mak

Edmun Chia Song Seng

Ac Lim

HonYeong Mak

A storage medium format is provided having a first band of a plurality of consecutive data storage tracks having user data stored thereto, a second band of a plurality of consecutive data storage tracks having other user data stored thereto, and a guard track medially disposed therebetween the first band and the second band and having system data stored thereto.

Data storage medium having system data stored in a guard band between zones of consecutive data storage tracks

A method to map defects is provided. A select data track of a storage medium is scanned for a defect. At least one data wedge affected by the defect on the select data track is identified. Each data wedge includes available area for writing user data defined between two servo wedges that include position information. The at least one affected data wedge is identified as unusuable.

Mapping defects on a data wedge basis

A storage medium having a boundary located along a surface of the storage medium that functions as a transition point for selectively operating a first writer and a second writer of a plurality of writers, where the location of the boundary is set based on writing capabilities of the plurality of writers.

Setting writer boundaries for multiple writers

A method is provided. The method includes determining that a data sector included in a select data track is in error, the data sector in error includes at least one identified data wedge. The at least one defective data wedge in the data sector in error is located. The method also includes moving the at least one defective data wedge by utilizing at least one spare wedge on the select data track.

Defect reallocation for data tracks having large sector size

A multistage decoder circuit has an error reduction stage that includes an adaptation circuit. The adaptation circuit provides adaptable error reduction as a function of bit error rate. The multistage decoder circuit has an energization control circuit that couples to the adaptation circuit. The energization control circuit controls an energization of the adaptation circuit as a function of actual or expected channel quality.

Decoder with energization control circuit

A method of recovering data on a storage medium is provided. A first error correction scheme is performed on a high risk region of the storage medium. A second error correction scheme is performed on a remaining portion of the storage medium.

Maintaining data integrity in a data storage system

A method, and system configured to implement the method, are provided. The method includes the steps of identifying a last usable track on a surface as a function of a parameter, and defining a standoff band of tracks relative to the last usable track to obtain an achieved maximum track on the surface. The last usable track is, in exemplary embodiments, a track beyond a default maximum track on a surface of a data storage medium.

Adaptive recording band expansion methodology

Apparatus and methods are disclosed that regulate head fly height so as to compensate for variation in height of a disk surface. An exemplary apparatus includes a circuit that detects disk height variation in response to variation in the gain of a variable gain amplifier, within an automatic gain control loop, that amplifies a read signal as the head reads from the disk surface. The circuit regulates the head fly height so as to compensate for the detected variation in disk height.

Fly height compensation using read gain control loop

A data recording apparatus includes a surface having a plurality of data tracks with leading track portions. A head moves along head paths over the data tracks to provide data access. The data access has a reduced reliability along a limited number of the leading track portions. Trailing path additions follow the head paths for the limited number of leading track portions. The trailing path additions providing overlapping data access for the limited number of leading track portions.

Overlapping data track access

A data storage medium and data storage system with improved efficiency of formatting are provided. One illustrative embodiment of the present invention pertains to a data storage medium. The data storage medium includes a first zone having servo information written with a first frequency, a second zone having servo information written with a second frequency, and a guard band disposed between the first zone and the second zone. The use of different frequencies in different zones contributes to optimizing the properties of the data storage medium, and the guard band contributes to optimizing the usage of the different zones.

Data storage medium with optimized servo format

A computer process establishes data frequencies for recording data in zones of a zone bit recording medium in a disc drive. At least three data points are identified for each zone correlating data frequencies and corresponding bit error rates, and a slope of a curve between each two data points is calculated. The slopes are averaged, and the data frequency is calculated based on the average slope. If a difference between the average and default slopes exceeds a first threshold value, or if a spread of the slopes exceeds a second threshold value, the data frequency is calculated based on the average slope and the default slope. In one embodiment, each of the three data points is generated by recording data in the zone at each of three selected data frequencies, reading the recorded data, and calculating bit error rates based on the recorded and read data.

Calculation of data frequencies in recording media

The thermal decay of data written to a magnetic mass storage medium is determined by measuring and analyzing the time-domain equalized-signal-to-noise ratio (ESNR) and equalized signal-to-total-distortion noise ratio (ESTDR) of written data. In some embodiments, a test track and a reference track are initialized from data. Subsequently, the reference track is re-initialized from the test data, and the time-domain ESNR and/or ESTDR measurements are made of the test track and the reference track, at predetermined time intervals. Later, the time-domain ESNR and ESTDR measurements are analyzed to determine the thermal decay of the data written. In another embodiment of the present invention, the ESNR and/or ESTDR measurements includes reading the data through a non-return-to-zero bus in phases, in which the phases are selected in sequence.

Systems, apparatus, and methods to determine thermal decay characterization from an equalized signal-to-noise ratio of a magnetic disc drive device

A disc drive includes a transducer having a separate element for writing information and a separate element for reading information to and from the disc. In a disc drive designated to read and write long sequential records, the track misregistration budget is reduced to account for previously written tracks not being encroached on one side. An initial track is written. Subsequent tracks are written after a seek in one direction. The subsequent track is written so that the initially written track is overwritten to one side and leaves a track having a width substantially equal to the width of the read element. Records can be written into data bands of a selected number of tracks. A guard band is left between groups of data bands so that data on tracks in subsequent data bands are not overwritten.

Method to achieve higher track density by allowing only one-sided track encroachment

An enhanced interleave type error correction method is provided in which decoding of an enhanced interleave block is done. Subsequently the decoding may be done by decoding the estimated codewords multiple times using a single error correction code. In addition, a decoder and a digital communication system for implementing the enhanced interleave type error correction method are provided.

Enhanced interleave type error correction method and apparatus

Systems and methods are provided through which a time domain equalized signal-to-noise-ratio (ESNR) of an electronic device is determined by executing ESNR determining firmware in the electronic device. The ESNR is used to perform rejection/acceptance testing of the electronic device during manufacturing of the device, and/or to perform read channel tuning and optimization. In one embodiment, determination of the ESNR includes both phase level retry and global level retry.

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Singapore, Singapore

UttHeng Kan