Seagate Technology Incorporated

Richard P Michel

Mark A Gaertner

Nurul Amin

Zheng Gao

Sining Mao

Johannes Van Ek

Anthony M Mack

Martin Louis Plumer

Dimitar Velikov Dimitrov

Michael C Kautzky

Mark Thomas Kief

Venkateswara R Inturi

Joshua Ward Christensen

Raye Abdoulie Sosseh

Dipeshkumar J Purani

Evgeny R Kharisov

Michael John Link

Dehua Han

Anil Kashyap

Vee Sochivy Kong

Tong Shirh Stone

Vladyslav Alexandrovich Vas'ko

Feng X Li

Ray V Rigles

Kevin Nghia Dao

Guofang Xu

Anand R Kharpate

Narayanan Krishnamurthy

A data storage device includes at least one data storage disc having at least one data storage surface, and at least one read head configured to communicate with the at least one data storage surface. The data storage device also includes a controller communicatively coupled to the at least one read head. The controller is configured to determine a fly height for the at least one read head over the at least one data storage surface as a function of a read workload associated with the at least one data storage surface or as a function of an ability to satisfy a read request to the at least one data storage surface on a first read attempt.

Adaptive read clearance for improving reader reliability

A method includes determining at least one of an areal density margin or a reliability margin for a combination of a head and a data storage surface in a data storage drive. The method also includes employing the determined at least one of the AD margin or the reliability margin to adjust an on-cylinder limit value associated with the combination of the head and the data storage surface.

Vibration-induced on-cylinder limit adjustment

A data storage device can consist of a data storage medium that has a recording surface accessed by a first transducing head suspended by a first actuator and a second transducing head suspended by a second actuator. The first actuator may be configured to access a first region of the recording surface while the second actuator is configured to access a second region of the recording surface. The first and second regions can be separate and non-overlapping.

Data storage device with separate actuators

Systems, devices, and method for phase slip recovery may include reading a plurality of data portions of a data block and positioning a mask over one or more data portions of the data block. The data portions following the mask may be shifted to provide a masked, reframed data block, and then the data block may be attempted to be decoded, which may be repeated until the data block is decoded.

Phase slip recovery

Systems and methods are disclosed to perform out of order LBA processing at a data storage device. A data storage device may be configured to receive a read command including a sequential LBA range, read data for the LBA range in non-sequential order and store the data to a buffer, and return the data to the host in sequential LBA order. The storage device may begin a read operation at a sector in the middle of the LBA range, and read the beginning of the LBA range on a next rotation of the media. The storage device may note the location of read errors without interrupting a read operation. Successfully read data may be buffered, while rereads and error recovery may be performed only on LBAs at which errors were encountered. Once the data from the LBA range has been acquired, the data may be organized into sequential order.

Out of order LBA processing

The disclosure is related to systems and methods of providing superparity protection to data. A storage device or other processing system, such as a host, may be capable of providing intermediate superparity protection to data. For example, superparity may be determined in response to a command received at a storage device. A superparity can be determined for read data to provide superparity protection to the read data. It may also be determined whether the read data is already protected by a valid superparity.

Superparity protection for data accessed responsive to a command

The disclosure is related to systems and methods of data recovery using frame matching and erasure windowing. Aspects involve using frame matching in conjunction with erasure windowing to overcome data corruption in a set of data to allow recovery of the set of data. When a synchronization mark indicating the position of a set of data in a superset of data is corrupted, frame matching in conjunction with erasure windowing are used to enable recovery of the set of data by applying one or more frame windows and one or more erasure windows to data including the set of data to recover the set of data.

Data recovery using frame matching and erasure windowing

Methods for determining a variable data frequency for recording data on a zone of a magnetic storage disc, each zone including a plurality of tracks and each track including a plurality of sectors, the method includes measuring a signal to noise ratio (S/N) around at least a first track in a first zone; and modulating a data frequency based on the measured S/N around the first track.

Methods of modulating data frequency

Systems and methods are disclosed for using track misregistration values, representing an amount of off-track deviation of a write element, to dynamically increment error scan counters for proximate storage areas. In certain embodiments, an apparatus may comprise a processor configured to perform a write operation to record data to a target track of a data storage medium using a write element, determine an amount of deviation of the write element from a center line of the target track, and increment an error scan counter for an area of the data storage medium proximate to the target track based on the amount of deviation.

Dynamic track misregistration dependent error scans

A beveled writing pole includes a top portion, a beveled portion, and a throat portion. The top portion has an end that defines a writing pole tip. The beveled portion adjoins the top portion and has a bevel that extends from the writing pole tip and increases a thickness of the writing pole proximate the pole tip. The throat portion is formed of the top and beveled portions and has tapered sides that extend from the writing pole tip and increase a width of the writing pole proximate the writing pole tip. A method of forming the beveled writing pole is also presented.

Method of forming a beveled writing pole of a perpendicular writing element

A read head shield having improved stability includes a ferromagnetic (FM) layer and an anti-ferromagnetic (AFM) layer adjacent the FM layer. The FM layer has a patterned shape and a domain configuration that is defined by a plurality of local magnetic domains that are stabilized in accordance with the patterned shape. The AFM layer is annealed to imprint thereon the stabilized local magnetic domains of the FM layer. The AFM layer operates to increase the stability of the domain configuration of the FM layer thereby providing improved resistance to domain configuration shift caused by the application of a strong magnetic field.

Read head shield having improved stability

Methods of fabricating spin valve sensors in accordance with the invention include forming a pinning layer from an antiferromagnetic material and forming a synthetic antiferromagnet adjacent the pinning layer. A free ferromagnetic layer is formed, and exchange tabs are formed adjacent outer portions of the free ferromagnetic layer for biasing the free layer. The exchange tabs are formed from the same antiferromagnetic material as the first pinning layer. Then, the magnetic moments of the synthetic antiferromagnet are set, and the magnetic moment of the free ferromagnetic layer is biased, during a single anneal in the presence of a single magnetic field.

Data head and method using a single antiferromagnetic material to pin multiple magnetic layers with differing orientation

A magnetic read head having an air bearing surface, a magnetoresistive sensor, an insulator layer, and first and second current contacts. The magnetoresistive sensor has a first portion adjacent to the air bearing surface and a second portion distal from the air bearing surface. The first and second current contacts are positioned in electrical contact with opposite edges of the first portion of the magnetoresistive sensor, and the insulator layer is positioned between the second portion of the magnetoresistive sensor and each of the first and second current contacts.

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Minneapolis, MN, United States of America

Richard P Michel