Abstract: According to embodiments, a magnetic disk apparatus includes a magnetic disk, a magnetic head, a temperature sensor, and a controller. The magnetic disk has formed therein a servo sector in which servo data including a first post code and a second post code is recorded. In the positioning of the magnetic head, the controller performs a correction using a third post code that is based on the first and second post codes and a first temperature detected by the temperature sensor.

Abstract: A method for writing repeatable run-out (RRO) data, to surfaces of a rotating magnetic storage medium in a storage device having two read channels, includes detecting, with a first head, using a first read channel, a servo sync mark (SSM) on a first track on a first surface, establishing a recurring servo-gating signal at a successive fixed interval from the SSM, detecting, with the first head, servo signals from the first track on occurrence of the recurring servo-gating signal, processing the servo signals from the first track, to generate first positioning signals for positioning the first head relative to the first track, following a similar procedure with a second read channel having a second head to generate second positioning signals for the second read head, and writing first and second RRO data to servo wedges of the first and second tracks according to the respective positioning signals.

Abstract: A device includes a servo controller that includes or that is coupled to memory. The memory stores multiple distinct disturbance control schemes. The servo controller is configured to select and implement one of the disturbance control schemes in response to receiving a command from a host. The servo controller can be implemented on a system on a chip.

Abstract: A data storage device includes a hard disk drive coupled to a printed circuit board (PCB), a volatile memory device coupled to the PCB, a non-volatile memory device coupled to the PCB, and a controller coupled to the PCB, such that the controller is in communication with the hard disk drive, the volatile memory device, and the non-volatile memory device. The controller is configured to identify patterns and/or structures of metadata for the hard disk drive, perform one or more of the following to the metadata to tailor the metadata: data shaping, content aware decoding, adaptive data trimming, and/or adaptive metablock sizing, and write the tailored metadata to the non-volatile memory device. The metadata is at least one of repeatable run out metadata, positioning error signal metadata, adjacent track interference metadata, and/or emergency power off metadata.

Abstract: Various illustrative aspects are directed to a system comprising: an actuator; a control object, controlled by the actuator; and one or more processing devices, configured to perform positioning control of the control object via the actuator, wherein performing the positioning control comprises: generating a trajectory control signal for a trajectory that comprises a polydyne acceleration ramp; and outputting the trajectory control signal to the actuator.

Abstract: The present disclosure is directed to placement of samples of a read sample offset operation in a memory sub-system. A processing device determines a shape of a valley to be subject to a read sample offset operation, where the valley corresponds to at least one programming distribution of a memory sub-system. The processing device selects a sampling rule from a set of sampling rules based on the shape of the valley. The processing device executes the read sample offset operation in accordance with the sampling rule.

Abstract: A controller for a magnetic disk device acquires a reproduction signal of servo burst data while moving a magnetic head along data tracks that intersect servo tracks at a plurality of points. The controller acquires correction values for correcting repeatable runout on a per servo sector basis based on the reproduction signal. The correction values include a first correction value, which is a correction value for a servo sector at a position where the data track and the servo track are substantially parallel to each other and a second correction value, which is a correction value fora servo sector at a position where the data track and the servo track are not substantially parallel to each other. The controller adjusts the first correction value based on the second correction value, and writes the correction values including the adjusted first correction value onto a magnetic disk.

Abstract: According to one embodiment, a method for manufacturing a magnetic disk device includes: moving a magnetic head such that a read head is located on a first learning position among a plurality of learning positions set in a radial direction of a magnetic disk; and learning RRO correction information related to the first learning position using the read head. The method further includes: moving the magnetic head such that the read head is located on a second learning position among the plurality of learning positions; and executing writing of the RRO correction information related to the first learning position using the write head in parallel while learning RRO correction information related to the second learning position using the read head when the read head is located on the second learning position.

Abstract: An information protection device includes: a random-contact mechanical Hall element provided with a conductive plate that has a prescribed conductive pattern, and a contact plate that is stacked on the conductive plate and that has, in an interior thereof, a connection portion partially contacting the conductive pattern; a communication line having multiple signal wires that are respectively connected to the connection portion in the random-contact mechanical Hall element; and a control unit configured to, through the communication line, monitor connection information between the connection portion and the conductive pattern in the random-contact mechanical Hall element, and determine, based on the connection information, whether or not iniquity has occurred in accordance with whether or not a connection state between the conductive pattern and the connection portion has changed from an initial setting.

Abstract: In accordance with one implementation, a method for adaptive in-field recalibration includes detecting a potential environmental disturbance for a first storage node in a mass storage system based on an indicator external to the first storage node, and initiating a recalibration of an operational parameter of the first storage node responsive to the detection.

Abstract: The disclosed technology provides a method that improves CCT in SMR device systems. In one implementation, the method comprises writing data to a shingled magnetic recording (SMR) band in a storage device, determining whether an off-track write has occurred, identifying unsafe written data in response to determining that an off-track write has occurred, determining whether caching space is available upon identifying unsafe written data, continue writing data to the SMR band without a write retry upon determining that caching space is available, and writing unsafe written data to the available caching space. In another implementation, the method comprises receiving a request to repair an encroached track in an SMR band, recovering encroached data to a dynamic random-access memory, determining whether caching space is available, writing the recovered data to the available caching space upon determining that caching space is available, and merging other cached data in the SMR band.

Abstract: A data storage device is disclosed comprising a first head actuated over the first disk surface, and a second head actuated over a second disk surface. A concurrent access of the first and second disk surface is executed by accessing the first disk surface without accessing the second disk surface during a single access interval, and after the single access interval, concurrently accessing the first and second disk surface during a dual access interval.

Abstract: A method of operating a data storage device is disclosed comprising an enclosure comprising a first head actuated over a first disk surface and a second head actuated over a second disk surface. A manufacture printed circuit board (PCB) is coupled to the enclosure, wherein the manufacture PCB comprises at least one dual channel configured to execute concurrent access operations. While the manufacture PCB is coupled to the enclosure, the data storage device is operated as a dual channel device. The manufacture PCB is decoupled from the enclosure and a product PCB is coupled to the enclosure, wherein the product PCB comprises a single channel configured to execute a single access operation.

Abstract: According to one embodiment, a magnetic disk device includes a first actuator which actuates a magnetic head portion including a magnetic head, a second actuator which adjusts a position of the magnetic head on a magnetic disk in a radial direction of the magnetic disk, and a control portion which determines a second measurement signal amplitude when a second transfer function is measured in accordance with a first gain estimated value of the second actuator and an amplitude of a first measurement signal amplitude to the second actuator applied when a first transfer function is measured, which calculates a second gain estimated value of the second actuator based on the first transfer function and the second transfer function, and which updates the first gain estimated value, using the calculated second gain estimated value.

Abstract: According to one embodiment, a disk device comprises a plurality of rotatable magnetic disks, a first actuator assembly, and a second actuator assembly. A slit provided in each of arms of the first actuator assembly is provided to be offset in a direction spaced away from a border plane between actuator assemblies with respect to a center of the arm in its thickness direction. A connection end portion of a wiring member is partially located in the slit, such as to be offset in a direction spaced away from the border plane, and disposed on a wiring board, and joined to the wiring board.

Abstract: A data storage device is disclosed comprising a first head actuated over a first disk surface, and a second head actuated over a second disk surface. During a first revolution of the disk surfaces, a first set of servo sectors are written to the first disk surface and a second set of servo sectors are written to the second disk surface, wherein the first set of servo sectors are circumferentially offset from the second set of servo sectors. During a second revolution of the disk surfaces, at least one of the servo sectors in the first set is read from the first disk surface and at least one of the servo sectors in the second set is read from the second disk surface to control a position of the first head over the first disk surface.

Abstract: According to one embodiment, a recording density setting method includes performing first process and performing second process. The first process including recording and reading data on and from a disk medium of a magnetic disk device, and acquiring first information for setting the read data to satisfy a certain quality criterion. The first information represents a first shape of a first plurality of unit regions. Each of the a first plurality of unit regions is a recording region of a unit capacity. The second process includes acquiring second information representing a second shape of the first plurality of unit regions, and setting a recording density on the basis of the second information. The second shape is formed by adding margin regions having the same area to the first plurality of unit regions of the first shape.

Abstract: A method for estimating parameters of a DC machine by the least-squares method is performed by a computer system. The method includes establishing a transient model of the DC machine; expressing discrete values of the terminal voltage, the armature current and the rotational speed of the DC machine by the polynomial regression after the DC machine is started; obtaining estimated values of an armature resistance, an armature inductance and a back electromotive force constant by the least-squares method; calculating a torque based on the back electromotive force constant and the armature current; obtaining estimated values of a moment of inertia and a viscous friction coefficient by the least-squares method; and outputting the estimated values of the armature resistance, the armature inductance, the back electromotive force constant, the moment of inertia and the viscous friction coefficient.

Abstract: According to one embodiment, a magnetic disk device includes a disk including a recording region including a servo sector, a head configured to write data to the disk and read data from the disk, and a controller configured to acquire a plurality of correction data for a repeatable runout of the recording region, the correction data respectively corresponding to a plurality of measurement positions set based on a first linearity error acquired by reading the servo sector, and to correct a position of the head based on the correction data.

Abstract: A data storage device is disclosed comprising a head actuated over a disk. A test pattern is read from a first part of the disk to generate a first read signal that is sampled to generate a first sequence of signal samples. The test pattern is read from a second part of the disk to generate a second read signal that is sampled to generate a second sequence of signal samples. A third sequence of signal samples is generated by at least one of amplitude-inverting the second sequence of signal samples, time-inverting the second sequence of signal samples, and amplitude-inverting and time-inverting the second sequence of signal samples. A quality metric is generated based on the first sequence of signal samples and the third sequence of signal samples, and a data density of the disk is configured based on the quality metric.

Abstract: According to one embodiment, a magnetic disk device reads servo information from a recording surface of a magnetic disk using a head, detects a position of the head based on the servo information, and estimates a vibration frequency of a disturbance applied to the head and filtering the estimated vibration frequency from a drive signal of the head. In the filtering, a position error is calculated using a target position of the head given when driving the head and the detected position of the head, a plurality of the vibration frequencies is estimated by executing the vibration frequency estimation based on the position error in a plurality of stages in series, and estimation results of the vibration frequencies are filtered in parallel from the drive signal of the head.

Abstract: According to one embodiment, a magnetic disk device includes a disk, a head that writes data to the disk and reads data from the disk, and a controller that obtains a gain to be changed according to a first value calculated based on first position information of the head and second position information of the head when writing a first track to the disk, calculates third position information of the head calculated based on the gain and the second position information, and writes a second track adjacent to the first track in a radial direction according to the third position information.

Abstract: Examples disclosed herein relate to a circuit having first and second analog processors and an analog-to-digital converter coupled to the first and second analog processors. The first analog processor provides a first analog signal having a voltage representing a function of a first vector and a second vector. The second analog processor provides a second analog signal having a voltage representing a function of a binary inverse of the first vector and the second vector. The analog-to-digital converter receives the first analog signal and the second analog signal, compares a signal selected from a group consisting of the first analog signal and the second analog signal to a reference voltage and based on the comparison to the reference voltage, determines a digital result representing the function of the first vector and the second vector.

Abstract: A shingled magnetic recording (SMR) hard disk drive (HDD) receives a read command for data associated with a range of logical block addresses (LBAs). In situations where a first portion of valid data associated with the range of LBAs is stored in an SMR region of the HDD and a second portion of valid data associated with the range of LBAs is stored in a non-SMR region of the HDD, the first portion is read from the SMR region in a single disk access and copied to a first buffer of the HDD, and the second portion is read from the non-SMR region in one or more disk accesses and copied to a second buffer of the HDD. The valid data associated with the range of LBAs stored in the second buffer are copied to the first buffer to be combined with valid data associated with the range of LBAs stored in the first buffer, and the combined valid data is then transferred to the host to complete execution of the read command.

Abstract: According to one embodiment a magnetic disk device, includes a disk which includes a plurality of servo sectors radially extending in a radial direction and being discretely disposed with a gap in a circumferential direction, a head which writes data to the disk and reads data from the disk, and a controller which writes a plurality of pieces of correction data with respect to a repeatable run-out of the disk to a plurality of first sectors disposed between the servo sectors in a first region, and writes the pieces of correction data to a plurality of second sectors disposed between the servo sectors in a second region different from the first region.

Abstract: The disclosed technology includes methods and systems that reduce off-track write retry operations in shingled magnetic recording systems. In one implementation, the method includes writing data to an initial track, determining which side of the initial track is a shingled side, calculating a percentage of position error signal (PES) at a shingled side end of the initial track (PES1) when an off-track write operation occurs, determining whether the PES1 meets a first pre-determined threshold, continue writing data to a second track responsive to determining the PES1 is below a first pre-determined threshold, calculating a percentage of PES at a shingled side end of the second track (PES2), determining whether a combined value of PES1 and PES2 is above a second predetermined threshold to determine a probability value of the initial track being erased, and continue writing to a third track if the combined value is below the second predetermined threshold.

Abstract: As may be implemented in accordance with one or more embodiments, an electrical connector such as a low-temperature co-fired ceramic (LTCC) connector is sealed to an opening in a base deck having bottom and/or side walls that define a cavity. A mechanical component is coupled to balance forces applied to opposing surfaces of the electrical connector, which can mitigate the application of high forces to connector pins and/or to the connector itself. Further, this balancing may be implemented to maintain a controlled bias force against the connector. The electrical connector may, for example, be hermetically sealed to the opening by a seal such as a gasket, epoxy or other material, which may be included in the electrical connector.

Abstract: An apparatus includes a disk locked clock system and a feedforward microactuator compensator. The disk locked clock system is configured to estimate a timing error and generate a timing error signal. The feedforward microactuator compensator is configured to generate a microactuator compensation signal, without use of a vibration sensor signal, in response to the timing error signal.

Abstract: Provided is a control device (1) for controlling a control target that comprises an inverse response system (2) having inverse response characteristics, i.e., in which the initial response rocks in the inverse direction from the input change direction. The control device (1) comprises an inverse response compensation system (5) that compensates for the inverse response characteristics in the control target. This inverse response compensation system (5) is configured to calculate a comparison value for the output of the control target and the output of a control target from which a portion or all of the unstable zeros have been removed and feed the calculated comparison value back to the input side of the control target.

Abstract: A data storage device comprising a head actuated over a disk comprising a plurality of tracks. The head is positioned over a target track, and a sampled position error signal (PES) is generated representing a position of the head relative to the target track. The sampled PES is filtered with a servo compensator to generate a sampled control signal, and the sampled control signal is upsampled to generate an upsampled control signal. The sampled PES is upsampled to generate an upsampled PES, and the upsampled PES is processed to generate compensation values. The upsampled control signal is combined with the compensation values to generate a compensated control signal, and the position of the head over the target track is adjusted based on the compensated control signal.

Abstract: According to one embodiment, a magnetic disk device including a disk, and a controller which calculates a first corrected value based on a first eccentricity of the disk, and writes a first track based on the first corrected value, wherein when the controller interrupts the process for writing the second track so as to overlap the first track at a first position, the controller measures a second eccentricity of the disk, and compares the first eccentricity with the second eccentricity, and when the first eccentricity is different from the second eccentricity, the controller restarts the process for writing the second track from a second position away from the first position in a radial direction.

Abstract: A method for writing servo data includes writing servo data as a head moves outward on a disk one step at a time, so as to overwrite part of servo data that have been written in a previous step, writing servo data as the head moves inward on the disk one step at a time, so as to overwrite part of servo data that have been written in a previous step, and writing one of two-phase burst data, or address data and the other of said two-phase burst data, at the radial position, so as to overwrite at least part of servo data written in each last step of the writings as the head moves outward and inward. The same address data are written in two consecutive steps as the head moves outward and as the head moves inward.

Abstract: A motor control device includes circuitry which reads a command value in synchronization with a control period, reads an output of an encoder connected to a motor, controls an output current to the motor based on the command value and the output of the encoder, and offsets a timing for reading the output of the encoder with respect to a timing for reading the command value.

Abstract: A method for manufacturing a disk device includes the steps of measuring a first gain of a control signal of a fine motion actuator while positioning a head to a first radial position of a disk medium using a coarse motion actuator but not the fine motion actuator, based on an auxiliary servo pattern recorded on the disk medium, measuring a second gain of a control signal of the fine motion actuator while positioning the head to a second radial position of the disk medium using the coarse motion actuator but not the fine motion actuator, based on the auxiliary servo pattern recorded on the disk medium, and determining gain correction values which are to be applied to a control signal for the fine motion actuator while performing servo pattern writing on the disk medium, based on the first and second gains.

Abstract: A storage device includes a controller configured to adjusts direct offline scan (DOS) parameters for a scan of a storage region based on a workload affecting the storage region to mitigate data loss due to adjacent track interference (ATI) while also mitigating performance delays due to DOS execution. In one implementation, a type of workload occurring in a region is determined by assessing a distribution of write track counter values corresponding to data tracks in the region.

Abstract: An apparatus for storing data includes a storage medium with user data regions and with servo data regions containing preamble patterns. Servo data in the servo data regions is written with a varying clock frequency across the storage medium. The apparatus also includes a head assembly disposed in relation to the storage medium and operable to read and write data on the storage medium. The apparatus also includes a preamble detection circuit adapted to search an input stream derived from the head assembly for the preamble patterns in a number of frequency bins.

Abstract: Uplink CoMP point selection is achieved, considering power consumption of a MTC device and uplink overhead. Two resource blocks of a first resource block containing a reference signal and a second resource block for transmitting user data are combined to achieve uplink CoMP. The time interval between these two resource blocks is a time of approximately several milliseconds to several tens milliseconds necessary that each eNodeB acquires reception quality to be collected to a Serving eNodeB via the X2 interface and analyze its content.

Abstract: First and second repeatable runout (ZAP) values are both located on a first virtual track of a magnetic disk. The first ZAP value is offset from the first virtual track center in a first direction and the second ZAP value is offset from the first virtual track center in a second direction opposite the first direction. At least one of the first and second ZAP values are accessed when performing repeatable runout correction for a writer of the read/write head that is being positioned over a second virtual track of the magnetic disk.

Abstract: A method and structure for dynamic memory re-allocation for an application runtime environment (ARE) includes receiving, through an interface of an application runtime environment (ARE), a first set of internal operational metrics of the ARE executing at a current setting S1 on a processor of a computer. A first performance P1 of the ARE is determined at the current setting S1 using the received first set of internal operation metrics. The current setting S1 of the ARE is varied to a new setting S2. A second set of internal operational metrics of the ARE executing at the new setting S2 is received through the interface of the ARE. A second performance P2 of the ARE is determined at the new setting S2, using the received second set of internal operation metrics. A memory allocation for the ARE is re-allocated, based on the determined performances P1 and P2.

Abstract: Systems and methods for resource allocation for a large sector format processing may include, but are not limited to, operations for: determining non-convergence of a magnetic disc sub-sector of a first magnetic disc sector within a processing time frame allocated to the magnetic disc sub-sector; determining a convergence of a second magnetic disc sector occurring in less time than a processing time frame allocated to the second magnetic disc sector; and processing the magnetic disc sub-sector during a portion of the processing time frame allocated to the second magnetic disc sector remaining after processing of the second magnetic disc sector.

Abstract: A hard disk drive with adjustable data track pitch has repeatable runout (RRO) fields stored in he servo sectors for each servo sector of each servo track, and thus without the need to store the RRO fields in the data tracks. The RRO fields for each servo sector have a radial length of at least two servo tracks (i.e., equal to or greater than twice the servo track pitch). The RRO fields in each servo track are shifted radially from RRO fields in adjacent servo tracks and circumferentially spaced from RRO fields in adjacent servo tracks. The read head reads two different RRO fields from the two servo tracks closest to the data track and the servo electronics interpolates a RRO value from these two RRO values. Thus even if the data track pitch is changed, RRO values can be obtained.

Abstract: A data storage device is disclosed comprising a head actuated over a disk comprising a plurality of servo tracks defined by servo bursts. A number of burst correction values are generated by reading at least one of the servo bursts at a number of different radial locations across the disk. The burst correction values are filtered to generate filtered burst correction values, and the filtered burst correction values are downsampled to generate downsampled burst correction values. The downsampled burst correction values are written to the disk, and the head is servoed over the disk by reading the downsampled burst correction values from the disk.

Abstract: A data storage device with improved data storage densities, coupled with lower hard error and write-inhibit events is described. A feed-forward write inhibit (FFWI) method enables data tracks to be written more densely. Alternatively, the FFWI method may reduce the hard error and write inhibit events to improve data storage performance. A concept of virtual tracks enables the FFWI method to be applied to the writing of circular data tracks with non-circular servo tracks, or to the writing of non-circular data tracks with PES data from circular servo tracks—in both cases, improvements to performance and/or storage densities are enabled. The FFWI method may also be applied to the case of both non-circular servo and data tracks.

Abstract: First and second position error signals (PES) are measured from respective first and second read heads that are simultaneously reading two different surfaces of a recording medium. A common repeatable runout (RRO) compensation signal and a differential RRO signal are determined based on the first and second PES. A voice coil motor that drives the first and second read heads is adjusted using the common RRO compensation signal, and first and second microactuators that respectively position the first and second read heads are adjusted based on the differential RRO signal.

Abstract: A data storage device is disclosed comprising a head actuated over a disk comprising a plurality of servo tracks defined by servo bursts. The head is positioned at a first radial location over the disk and a first burst correction value is generated by reading at least one of the servo bursts. The head is positioned at a second radial location over the disk and a second burst correction value is generated by reading at least one of the servo bursts. The head is positioned at a third radial location over the disk and the first burst correction value and the second burst correction value are written at the third radial location. The head is servoed over the disk by reading the first and second burst correction values.

Abstract: A hardware multi-stream multi-standard video decoder device. A command parser accesses a plurality of video streams, identifies a video encoding standard used for encoding video streams of the plurality of video streams, and interleaves portions of the plurality of video streams. A plurality of hardware decoding blocks perform operations associated with decoding the plurality of video streams, wherein different subsets of the plurality of hardware decoding blocks are for decoding video streams encoded using different video encoding standards, such that interleaved video streams are decoded by activating subsets of the plurality of hardware decoding blocks for use in decoding the plurality of video streams. A plurality of register sets store parameters associated with the plurality of video streams.

Abstract: A hardware multi-standard video decoder device. A command parser accesses a video stream and identifies a video encoding standard used for encoding the video stream. A plurality of hardware decoding blocks perform operations associated with decoding the video stream, wherein different subsets of the plurality of hardware decoding blocks are for decoding video streams encoded using different video encoding standards.

Abstract: Radially-coherent data reading from, and data writing to, a magnetic disk use non-coherently written synchronization signals on the disk. In a form, the radially-coherent data reading and writing is performed using a magnetic head/disk tester which includes a spinstand for supporting a spinning magnetic disk, a magnetic head assembly, a write channel network for generating a write data signal for application to a write element of the magnetic head, a read channel for receiving a read-back signal from a read element of the magnetic head assembly, and a signal processing system that analyzes a read-back signal from a disk and provides synchronization signals for radially-coherent data reading and data writing.

Abstract: A data storage device is disclosed comprising a head actuated over a disk comprising a plurality of tracks. A defect scan of at least one of the tracks is executed, and a log entry is generated when a defect is detected. After the defect scan, a verify operation is executed for at least two of the detected defects. A number of times the verify operation detects a false defect is counted, and whether the head is defective is determined based at least partly on the count.

Abstract: Improved flaw scan circuits are provided for repeatable run out data. RRO (repeatable run out) data is processed by counting a number of RRO data bits detected in a servo sector; and setting an RRO flaw flag if at least a specified number of RRO data bits is not detected in the server sector. The RRO flaw flag can also optionally be set by detecting an RRO address mark in the servo sector; counting a number of samples in the servo sector after the RRO address mark that do not satisfy a quality threshold; and setting the RRO flaw flag when the counted number of samples that do not satisfy the quality threshold exceeds a specified flaw threshold. If the RRO flaw flag is set, the RRO data can be discarded, and/or an error recovery mechanism can be implemented to obtain the RRO data.