Seagate Technology Incorporated

Kay Hee Tang

Aik Chuan Lim

Jeffrey Soon Beng Sim

Xiong Liu

Mark A Gaertner

Jian Qiang

UttHeng Kan

Choon Kiat Lim

Edmun ChianSong Seng

YongPeng Chng

WeiLoon Ng

Utt Heng Kan

AikChuan Lim

Steven TianChye Cheok

Edmun Chian Song Seng

Chee Hou Peng

An apparatus includes a data storage medium having a plurality of tracks. The apparatus also includes a write history buffer configured to store a history of prior write commands to the plurality of tracks. The apparatus further includes a controller communicatively coupled to the write history buffer. The controller is configured to receive a new write command directed to a first portion of a first track of the plurality of tracks on the data storage medium. The controller is further configured to determine whether to update ATI contribution measures from the first track based on the history of write commands to the first track.

Managing adjacent track interference in a data storage device

In one embodiment of the present invention, systems and methods are provided through which the capacity of a defect buffer in a microcontroller of a mass storage device is determined without regard for the quantity of defects on a recording medium. The capacity of the defect buffer is determined in varying examples, based on the amount of available buffer space and/or the application of the storage device. In one embodiment, the capacity of the defect buffer is less than the quantity of defects on the recording medium, wherein entries in a defect table on the recording medium are swapped in and out of the defect buffer as needed, such as using a most-recently-used scheme. In another embodiment of the present invention, systems and methods are provided through which the defect table is partitioned into a plurality of segments that are physically distributed throughout the recording medium.

System and method for adaptive storage and caching of a defect table

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.

System and method to determine the time domain equalized signal-to-noise ratio of a mass storage device

A method of and apparatus for generating a reader-to-writer offset for a head positioned over a track on a disc in a disc drive having a plurality of tracks is disclosed. A reader and a writer are mounted on the head in a non-overlapping manner with a gap between the reader and the writer, which is known as the reader-to-writer offset. A disc drive controller is operably connected to the reader and the writer. The disc drive controller determines the reader-to-writer offset of the head for each track by computing the difference between a first head position x1 and a second head position x2. The first head position x1 is an optimal head position for writing information on the track and the second head position x2 is a midpoint of an off-track capability (OTC) of the head. The OTC is a portion of a track pitch over which the reader is expected to read information that is free of an incorrigible bit error such that the writer-to-reader track misregistration (TMR) is minimized as the head is radially displaced the reader-to-writer offset to read information written on the track or to write information on the track.

Optimal reader-to-writer offset measurement of a head in a disc drive for reduced track misregistration

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Singapore, Singapore

Kay Hee Tang