Abstract: A circuit may be configured to adjust a correction signal for each phase of an electric motor based on a rotational position of a spindle of the electric motor, generate a distorted waveform based on the correction signal, and drive the electric motor in response to the distorted waveform. In some examples, back electromotive force (BEMF) may be determined in order to adjust a motor drive waveform, which may reduce or eliminate motor vibrations. A motor drive signal may be pre-warped (i.e. distorted) such that when the correctional signal and drive signals are combined, there is a reduction in acoustic emissions or motor vibrations. Other parameters, such as cogging torque, may be measured to reduce motor vibration and acoustic emissions.

Abstract: A system includes a data storage medium and a shockwave generator. The data storage medium includes cells and a plurality of layers. Each cell is configured to store information therein. At least two cells are arranged in a horizontal plane within a same layer of the plurality of layers of the data storage medium and at least two cells are arranged in a vertical plane in different layers of the plurality of layers of the data storage medium. The shockwave generator is configured to generate a shockwave signal that travels through a layer of the plurality of layers of the data storage medium. A target cell within the layer stores information responsive to a beam emitted from an emitter targeting the target cell as the shockwave signal is passing through the target cell. The target cell maintains the information after the shockwave signal exits through the target cell.

Abstract: Systems and methods are disclosed to abort a command at a data storage controller, in accordance with certain embodiments of the present disclosure. In some embodiments, an apparatus may comprise a data storage controller configured to receive an abort indicator from a host device, generate an abort tracking indicator at a receiving unit configured to receive commands from the host device, monitor to determine when the selected command is received at the receiving unit based on the abort tracking indicator, and abort the selected command when the selected command is received at the receiving unit. In some embodiments, the data storage controller may generate an abort tracking indicator at a completion unit configured to notify the host device of completed commands, and monitor for the selected command at the completion unit based on the abort tracking indicator.

Abstract: An apparatus may include a circuit configured to generate, by an analog to digital converter (ADC), one or more ADC samples based on an input signal. The circuit may be further configured to generate a first estimated signal using a first channel pulse response estimation with a gain constraint based on the one or more ADC samples and generate a second estimated signal using a second channel pulse response estimation with a phase constraint based on the one or more ADC samples.

Abstract: Measuring surface features of a plurality of sliders including capturing an image of a surface of a slider bar using a large aperture interferometer, where the slider bar includes at least one slider of the plurality of sliders, and where the image includes surface height data for the slider bar surface and the included at least one slider. A bar height map is created of the slider bar based upon the surface height data of the captured image. Individual slider surfaces having individual slider height maps are identified, based at least in part of the number of sliders included on the slider bar.

Abstract: Embodiments described herein provide an apparatus that is operable with a disk drive. The apparatus includes a memory device operable to store a plurality of bit sets. Each bit set identifies a track and a sector of the disk drive and a number of times that the track of the disk drive has been written. A controller of the disk drive is operable to increment the number when the track is written. Each bit set comprises a number of bits that is established according to track location of the disk drive.

Abstract: An apparatus includes a circuit, a code modulator, and an actuator. The circuit is operable to detect displacements of a rotating object while in motion. The circuit is operable to detect a position of the displacements and to generate a signal associated therewith. The code modulator is operable to generate a modulated signal based on the position and the displacements. The actuator is operable to apply a force to the rotating object, wherein the force is based on the modulated signal.

Abstract: An apparatus comprises a slider configured for heat-assisted magnetic coupled to a controller. The slider comprises a writer, a heater, a near-field transducer, and an optical waveguide for communicating light from a laser diode to the near-field transducer. The controller is configured to set a target pre-write clearance of the slider prior to performing a write operation, set a target write clearance of the slider for performing the write operation, and determine a difference between the target pre-write and write clearances to define a target pre-write clearance offset. The controller is also configured to measure, for a plurality of different target pre-write clearance offsets, a writability metric for the slider while sweeping a laser diode current, and adjust the target pre-write clearance offset so that the writability metric reaches a predetermined threshold. The controller is further configured to perform subsequent write operations using the adjusted target pre-write clearance offset.

Abstract: Apparatus and method for managing data in a hybrid data storage device. In some embodiments, a hybrid device has a hard disc drive (HDD) controller circuit coupled to non-volatile rotatable media and a solid state drive (SSD) controller circuit coupled to non-volatile solid state memory. A top level controller circuit directs a selected access command one of the HDD controller circuit or the SSD controller circuit responsive to a selected parameter associated with the selected access command. In a normal mode, the top level controller circuit directs a transfer of data between the host and the HDD controller circuit and handles host interface communications. In a tunneling mode, the top level controller circuit directly connects the HDD controller circuit to the host device. In this way, tunnel mode bypasses processing operations required by the top level controller circuit. Tunnel mode and normal mode may be selected on a command-by-command basis.

Abstract: A slider of a heat-assisted recording head comprises electrical bond pads coupled to bias sources and a ground pad, an air bearing surface, and a waveguide configured to receive light from a laser source. A contact sensor proximate the air bearing surface is coupled between a first bond pad and a second bond pad. A bolometer is coupled to a reference thermal sensor. The bolometer is situated at a slider location that receives at least some of the light communicated along the waveguide. The reference thermal sensor is situated at a slider location unexposed to the light communicated along the waveguide. The bolometer and reference thermal sensor are coupled between the first and second bond pads and in parallel with the contact sensor. A ground connection is coupled to the ground pad and at a connection between the bolometer and the reference thermal sensor.

Abstract: Embodiments described herein are operable with a storage device. In one embodiment, a method provides for buffering first portions of incoming sequential data from a plurality of channels in a buffer, and identifying locations of the storage device to store the first portions of the incoming sequential data. The method also provides for directly writing the first portions of the incoming sequential data from the buffer to the identified locations of the storage device.

Abstract: Provided herein is an apparatus including a top continuous layer and a bottom continuous layer under the top continuous layer. The top continuous layer and the bottom continuous layer are antiferromagnetically coupled. A number of granular columns are under the bottom continuous layer. The number of granular columns include at least a first granular layer under the bottom continuous layer and a second granular layer also under the first granular layer. The first granular layer and the second granular layer are separated by a non-magnetic spacer. The first granular layer and the second granular layer are ferromagnetically coupled. The first granular layer is antiferromagnetically coupled to the bottom continuous layer.

Abstract: A data writer can have at least a write pole laterally disposed between first and second side shields and vertically disposed between a wrap-around shield and a front shield. The write pole may be separated from the side shields and the wrap-around shield by a lamination of first and second non-magnetic layers.

Abstract: A system may comprise a finite impulse response circuit configured to receive one or more samples of a first signal and generate an equalized signal based on the plurality of samples of the input signal and one or more updatable tap coefficients. The system may include an adaptation circuit configured to update the one or more updatable tap coefficients based on the plurality of samples of the input signal. The system may further comprise a recovery circuit configured to accumulate one or more retuning values based on the plurality of samples of the input signal and, in response to an error condition, generate one or more retuned tap coefficients for the finite impulse response circuit based on the one or more retuning values and replace the one or more updatable parameters with the one or more retuned parameters.

Abstract: Apparatus and method for detecting unauthorized tampering with a data storage device having a housing and a memory. A first identifier value is stored on an external surface of the housing and a second identifier value is stored within the memory. The first and second identifier values are combined in a predetermined order to form a combined identifier value for which a digital signature is generated using a private key, and the digital signature is stored on the storage device. The digital signature, the first and second identifier values, and one or more dummy identification values are retrieved from the storage device and stored in a memory of a verification device, which combines the retrieved first and second identifier values in the predetermined order to generate a retrieved combined identifier value. The storage device is authenticated using the retrieved combined identifier value, the digital signature and a public key.

Abstract: An apparatus is disclosed. The apparatus includes a storage layer, a first write layer, and a second write layer. The first write layer is disposed over the storage layer. The second write layer is disposed over the first write layer. The anisotropy field and magnetization associated with the second write layer at writing temperature is greater than anisotropy field and magnetization associated with the first write layer at the writing temperature.

Abstract: Methods and apparatuses for detecting mode hopping in a laser diode or other optical energy source in heat-assisted magnetic recording. An output power of the laser diode or other optical energy source is measured and the output power is differentiated over time to determine a rate of change. If it is determined that the rate of change exceeds a threshold value, a fault signal is asserted indicating a potential mode hopping event.

Abstract: Apparatus for managing power in a data storage device, such as a solid state drive (SSD). In some embodiments, an energy management circuit supplies electrical power to a non-volatile memory (NVM). The energy management circuit has cascaded first and second E-Fuse switch circuits each with an input terminal and an output terminal. The second E-Fuse switch circuit receives input power from the first E-Fuse switch circuit used as a rail voltage for the device. The second E-Fuse switch circuit is configured to monitor the rail voltage, deactivate the first E-Fuse switch circuit responsive to the rail voltage falling below a predetermined threshold, and supply backup power to the device from a backup power source.

Abstract: A system includes a data storage medium comprising layers, an excitation circuit, and an emitter. Each layer comprises cells arranged in a horizontal plane. Cells in different layers are arranged in a vertical plane of the data storage medium. The excitation circuit excites a layer during excitation period. Exciting the layer changes an optical property of the layer during the excitation period. The emitter emits a first and a second beam onto a first and a second cell of the layer being excited during the excitation period to orient electrical charges within the first and the second cell to a first and second oriented values and their intensity to a first and second intensity values respectively. The first and second cells maintain the first and second oriented values and the first and second intensity values after the excitation period is over or in absence of the layer being excited.

Abstract: An apparatus including a heat sink layer and a magnetic recording layer over the heat sink layer. In addition, a thermochromic layer is over the heat sink layer, wherein the thermochromic layer includes a first optical absorbance at a first temperature and a second optical absorbance at a second temperature.