Seagate Technology Incorporated

Raye Abdoulie Sosseh

Evgeny R Kharisov

Mark A Gaertner

Kenneth A Haapala

Josiah Natan Wernow

Binh Kim Lieu

John Christopher Morris

Brian Thomas Edgar

Bin Huang

Mark Lowell Elliott

Tzung-Sz Shen

Ying Qi

Jon David Trantham

Mehmet Fatih Erden

Qiang Bi

Lealon Ray McKenzie

Randall D Hampshire

Tao Zhang

Richard P Michel

Dustin Mark Cvancara

Paul Michael Wiggins

Ryan Todd Lyle

Colin Graham Presly

Mark Larry Birtzer

Christopher Thomas Cole

James Wilford DuLaney

Zai Yu Nang

Seow Zhao Li

Optimization of an aerial density capability (ADC) leveraging different qualities of media surfaces to which sub-portions of an encoded data portion are written. That is, data may be encoded to generate an encoded data portion according to a coding scheme. In turn, the encoded data portion may be divided into a plurality of sub-portions, each of which may be written to different media surfaces in a storage drive. The sub-portions may be read from the different media surfaces and combined to generate a recreated encoded data portion that is decoded using the coding scheme. As the encoded data portion is divided into sub-portions, the combined sub-portions may provide different error rates or signal-to-noise ratios that may allow for lower quality sub-portions to be assisted during the decoding process by higher quality sub-portions.

Increased aerial density capability in storage drives using encoded data portions written to media surfaces with different aerial density capabilities

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

Systems and methods are disclosed for employing a media read cache in a storage device. In certain embodiments, an, an apparatus may comprise a data storage drive including a volatile read cache, and a disc memory including a primary data storage region of the storage device configured for long-term storage of data via persistent logical block address to physical block address mapping, and a media read cache region configured to store a copy of data from the volatile read cache. The data storage drive may be configured to perform a read operation including: retrieve read data from the volatile read cache based on determining that the read data is available in the volatile read cache, and retrieve the read data from the media read cache based on determining that the read data is not available in the volatile read cache and is available in the media read cache.

Media read cache

A data storage device includes at least one data storage medium having a plurality of tracks. The data storage device also includes at least one actuator that supports at least one head that is configured to interact with different tracks of the plurality of tracks on the at least one data storage medium to service commands from a host. The data storage device further includes a seek control circuit communicatively coupled to the at least one actuator. The seek control circuit is configured to store the commands from the host in at least one queue for execution by the at least one actuator. The seek control module is also configured to adjust power provided to the at least one actuator for seek operations to the different tracks of the plurality of tracks based on command age-related measurements of the commands from the host.

Power latency control in data storage devices

Illustrative systems and methods disclosed herein may change or modify a seek during mid-seek for various reasons and may set seek speeds for various seeks to less than the maximum possible seek speed to, for example, facilitate seek target change or modifications mid-seek. For instance, the seek speeds for lower priority commands or commands at risk for deprioritization may be set to speeds less than the maximum possible seek speed.

Modifying seek operations mid-seek

A data storage device includes a first data storage surface and a second data storage below the first data storage surface. The data storage device also includes a first micro-actuator coupled to a first arm that supports a first head over the first data storage surface, and a second micro-actuator coupled to a second arm that supports a second head over the second data storage surface. The data storage device further includes a coarse actuator, to which the first and second arms are coupled, that positions the first head and the second head between corresponding first and second tracks on the respective first and second data storage surfaces. Micro-actuator drive circuitry finely positions the first head over the first track and the second head over the second track by concurrently driving the first micro-actuator and the second micro-actuator in opposite directions.

Parallel servo control in a data storage device

Implementations disclosed herein include a method to synthesize the controller of a multi-stage servo control system with multiple actuators in a hard disk drive by dividing controller synthesis into multiple dual-stage steps. The method includes measuring a first output of a first plant corresponding to a first actuator, measuring a second output of a second plant corresponding to a second actuator, designing a first controller responsive to the first output, designing a second controller responsive to the second output, and combining the first output and the second output to obtain a first combined output in a first dual-stage. The method also includes designing a third controller responsive to the first combined output, measuring a third output from a third plant corresponding to a third actuator, designing a fourth controller responsive to the third output, and combining the first combined output and the third output to obtain a second combined output.

Multi-stage servo control design system

A back electromotive force of a rotating motor is converted into a voltage for a load by driving, in accordance with a duty cycle, at least one switching circuit that couples the back electromotive force to a load through a rectifying circuit. An error signal is generated that is a difference between the load voltage and a reference voltage. The duty cycle is controlled as a function of the error signal to cause the load voltage to approach the reference voltage.

Efficient energy recovery in disk drive during power loss

An apparatus includes a first controller, a second controller, and a coupling compensator. The first controller is configured to generate a first voice coil motor (VCM) control signal in response to a first position error signal. The second controller is configured to generate a second VCM control signal in response to a second position error signal. The coupling compensator is configured to generate a first feedforward correction signal in response to the first VCM control signal. The first feedforward correction signal modifies the second VCM control signal to generate a modified second VCM control signal.

Feedforward compensation for multi-actuator hard drives

Certain exemplary aspects of the present disclosure are directed towards apparatuses and methods which mitigate the effect of speaker vibration on a disc drive. Audio associated with a speaker output is detected and triggers the generation of an output signal indicative of speaker vibration associated with such an audio output of a speaker. A magnetoresistive transducer of the disc drive is positioned relative to a storage medium based on the output signal, a target data storage location in the storage medium from which data is to be accessed via the positioning, and the position of the transducer. The output signal mitigates the effect of the speaker vibration on the transducer.

Disc drive speaker vibration mitigation

An apparatus includes a first read/write head coupled to a first micro actuator, a second read/write head coupled to a second micro actuator, an actuator and a controller. The actuator is coupled to both the first and second micro actuators. The controller is configured to position the first read/write head in response to a first micro actuator control signal and an actuator control signal. Further, the controller is configured to position the second read/write head in response to a second micro actuator control signal and the actuator control signal. The positioning of the first and second read/write heads by the controller is performed substantially simultaneously.

Disk drive with parallel head actuation

An apparatus includes a plurality of magnetic read/write heads, a system controller and a switching network. Each of the magnetic read/write heads includes a read sensor element configured to perform a read operation and a write element configured to perform a write operation. The switching network is coupled between the plurality of magnetic read/write heads and the controller. Further, the switching network is configured to substantially simultaneously select elements from at least two of the plurality of magnetic read/write heads in response to a command from the controller such that the operations of the selected elements are performed substantially simultaneously to establish a manufacturing parameter of a disk drive.

Apparatus and methods to reduce hard disk drive manufacturing test time

The disclosure is related to systems and methods for adaptive seek latency in a rotating storage device. In one example, a servo control circuit can be configured to determine a seek latency and provide the seek latency to another controller or control circuit that is configured to implement the seek latency. Further, the servo control circuit can calculate the seek latency based on a measurement of a variable condition of a device and the servo controller can adjust the seek latency as the condition varies. In some examples, the variable condition may include power measurements, temperature measurements, a fault rate, other conditions, or any combination thereof. Also, different algorithms for calculating the seek latency may be implemented based on a selected goal of the system, such as power savings or reduced head vibration.

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Minneapolis, MN, United States of America

Raye Abdoulie Sosseh