US Pat. No. 9,183,877

DATA STORAGE DEVICE COMPRISING TWO-DIMENSIONAL DATA DEPENDENT NOISE WHITENING FILTERS FOR TWO-DIMENSIONAL RECORDING

Western Digital Technolog...

1. A data storage device comprising:
a disk comprising a plurality of data tracks;
a head actuated over the disk, wherein the head comprises a first read element and a second read element; and
control circuitry operable to:
position the first read element over a first data track k?1 and position the second read element over a second data track
k;

sample a first read signal from the first read element to generate first signal samples;
sample a second read signal from the second read element to generate second signal samples;
a first two-dimensional (2D) equalizer configured to perform 2D equalization of the first signal samples and the second signal
samples to generate first 2D equalized samples;

a second 2D equalizer configured to perform 2D equalization of the first signal samples and the second signal samples to generate
second 2D equalized samples;

a first 2D data dependent noise whitening (DDNW) filter configured to perform 2D DDNW of the first and second 2D equalized
samples to generate first 2D noise whitened samples;

a second 2D DDNW filter configured to perform 2D DDNW of the first and second 2D equalized samples to generate second 2D noise
whitened samples; and

a 2D sequence detector configured to detect a first data sequence recorded in the first data track from the first and second
2D noise whitened samples and to detect a second data sequence recorded in the second data track from the first and second
2D noise whitened samples.

US Pat. No. 9,059,736

METHODS, SOLID STATE DRIVE CONTROLLERS AND DATA STORAGE DEVICES HAVING A RUNTIME VARIABLE RAID PROTECTION SCHEME

Western Digital Technolog...

1. A solid state drive controller, comprising:
a processor, the processor being configured to couple to an array of flash memory devices, the array comprising a plurality
of dies, each die comprising a plurality of flash blocks (F-Blocks), each F-Block comprising a plurality of flash pages (F-Pages),
at least some of the F-Page comprising at least one error correcting code page (E-Page), and at least some of the E-Pages
comprising a variably-sized error correction code (ECC) portion and a corresponding variably-sized data portion, the variably-sized
data portions within one F-Page defining, in the aggregate, an F-Page data portion,

wherein the processor is configured to:
define an S-Page that comprises a plurality of F-Pages from one or more of the plurality of dies;
within the S-Page,
store an E-Page error correction code within the variably-sized ECC portion of each E-Page within the F-Pages to correct an
error within the corresponding variably-sized data portion;

designate at least one F-Page having a largest size F-Page data portion among the F-Pages in the S-Page as a Check Page; and
store a cross-F-Page error correction code within the at least one Check Page.

US Pat. No. 9,177,638

METHODS AND DEVICES FOR AVOIDING LOWER PAGE CORRUPTION IN DATA STORAGE DEVICES

Western Digital Technolog...

1. A data storage device, comprising:
a plurality of Multi-Level Cell (MLC) non-volatile memory devices comprising a plurality of lower pages and a corresponding
plurality of higher-order pages;

a controller coupled to the plurality of MLC non-volatile memory devices and configured to write data to and read data from
the plurality of lower pages and the corresponding plurality of higher-order pages; and

a buffer comprising non-volatile memory, the buffer being separate from the plurality of MLC non-volatile memory devices and
coupled to the controller;

wherein the controller is configured to:
accumulate data to be written to the MLC non-volatile memory devices;
allocate space in the buffer and write the accumulated data to the allocated space in the buffer;
write at least a portion of the accumulated data in a lower page of the MLC non-volatile memory devices;
detect a loss of power;
read data from the buffer and write at least a portion of the read data to the MLC non-volatile memory devices after power
is restored to the data storage device subsequent to detecting the loss of power; and

de-allocate space in the buffer that stores data written to the lower page when all higher-order pages corresponding to the
lower page have been written in the MLC non-volatile memory devices.

US Pat. No. 9,170,939

EARLY DE-ALLOCATION OF WRITE BUFFER IN AN SSD

Western Digital Technolog...

1. A data storage system, comprising:
non-volatile solid state memory comprising non-volatile storage units and a temporary register;
a data storage controller configured to receive a write command including a plurality of logical segments of data from a host;
a write buffer allocated by the controller to receive a portion of the plurality of logical segments of data and accumulate
a physical segment of data corresponding to a write unit of the solid state memory; and

a solid state memory controller coupled to the non-volatile solid state memory, the solid state memory controller configured
to transmit the accumulated data from the write buffer to the temporary storage register in the solid state memory each time
the write buffer accumulates a physical segment of data,

wherein the data storage controller is further configured to:
acknowledge completion of the write command to the host after the last logical segment of data is written to the write buffer;
and

deallocate the write buffer after the solid state memory completes reception of the accumulated data from the write buffer
into the temporary storage register.

US Pat. No. 9,454,474

METHODS, DEVICES AND SYSTEMS FOR TWO STAGE POWER-ON MAP REBUILD WITH FREE SPACE ACCOUNTING IN A SOLID STATE DRIVE

Western Digital Technolog...

1. A data storage device controller configured to couple to a non-volatile memory comprising a plurality of blocks, each block
being configured to store a plurality of physical pages at predetermined physical locations, the controller comprising:
a processor configured to program data to and read data from the non-volatile memory, the data being stored in a plurality
of logical pages;

a volatile memory comprising a logical-to-physical address translation map configured to enable the processor to determine
a physical location, within one or more physical pages, of the data stored in each logical page; and

a plurality of journals stored in the non-volatile memory, each journal corresponding to at least one of the plurality of
blocks and comprising a plurality of journal entries associating one or more physical pages to each logical page, wherein
each of the plurality of journals covers a pre-determined range of physical pages within one of the plurality of blocks,

wherein the controller is configured, upon startup, to:
read each of the plurality of journals in an order and to rebuild the map in the volatile memory from the read of each of
the plurality of journals;

indicate a readiness to process data access commands after the map is rebuilt;
rebuild a table from the map and select, based on the rebuilt table, at least one of the plurality of blocks for garbage collection
after having indicated the readiness to process data access commands;

locate a corresponding journal for the selected block to determine whether any entries in the corresponding journal point
to valid data on the selected block;

relocate all of the valid data, as indicated by the corresponding journal, from the selected block to another block in the
non-volatile memory; and

generate a new journal for the block storing the valid data.

US Pat. No. 9,323,467

DATA STORAGE DEVICE STARTUP

Western Digital Technolog...

1. A data storage device (DSD), comprising:
a disk for storing data;
a solid state memory including a non-volatile cache for storing data; and
a controller configured to:
receive a write command from a host to store data in the DSD;
determine whether the DSD is in a startup period of the DSD, wherein the host accesses boot up data from the DSD during the
startup period; and

if it is determined that the DSD is in a startup period:
store the data for the write command in the non-volatile cache of the solid state memory;
update a list to include an entry for the data for the write command, the list including entries indicating data written during
a plurality of startup periods of the DSD; and

use the list to determine whether to invalidate or delete the data for the write command in the non-volatile cache.

US Pat. No. 9,218,279

ATOMIC WRITE COMMAND SUPPORT IN A SOLID STATE DRIVE

Western Digital Technolog...

1. A method of performing an atomic write command in a data storage device comprising a volatile memory and a plurality of
non-volatile memory devices that are configured to store a plurality of physical pages, the method comprising:
storing data in a plurality of logical pages (L-Pages), each of the plurality of L-Pages being associated with a logical address;
maintaining a logical-to-physical address translation map in the volatile memory, the translation map being configured to
enable determination of a physical location, within one or more of the physical pages, of the data referenced by each logical
address;

receiving the atomic write command;
maintaining, in the plurality of non-volatile memory devices, a plurality of system journals (S-Journals) defining physical-to-logical
address correspondences, each journal comprising a plurality of system journal entries, each entry configured to associate
the one or more physical pages to an L-Page;

storing data specified by the atomic write command in at least one L-Page, the storing further comprising generating an S-Journal
entry for each of the at least one L-Page storing data specified by the atomic write command, the generated S-Journal entry
being configured to enable a determination of whether the atomic write command was completed or not completed upon reconstruction
of the translation map; and

deferring an update to at least one entry in the translation map associated with the at least one L-Page storing the data
specified by the atomic write command until all L-Pages storing data specified by the atomic write command have been written
in a power-safe manner.

US Pat. No. 9,143,005

BACKUP ENERGY STORAGE MODULE WITH SELECTABLE CHARGE STORAGE ELEMENTS FOR PROVIDING BACKUP POWER TO A LOAD

Western Digital Technolog...

1. A backup energy storage module comprising:
a plurality of charge storage elements, each charge storage element operable to be charged to a backup voltage; and
control circuitry operable to:
monitor a supply voltage that provides power to a load;
determine when the supply voltage falls below a threshold level;
select a first charge storage element to provide power to the load;
determine when the backup voltage on the first charge storage element falls to a reference level; and
select a second charge storage element to provide power to the load if the supply voltage remains below the threshold level.

US Pat. No. 9,099,133

DISK DRIVE SERVO CONTROL USING HYBRID UPSAMPLE FILTER

Western Digital Technolog...

1. A disk drive comprising:
a disk comprising a plurality of servo tracks, wherein each servo track comprises a plurality of servo sectors;
a head;
an actuator for actuating the head over the disk in response to an actuator control signal; and
control circuitry operable to:
read the servo sectors to generate a first sequence of control samples x[k] at a sample frequency corresponding to a frequency
of the servo sectors;

use a hybrid upsample filter to upsample by a factor of N the first sequence of control samples x[k] to generate a second
sequence of control samples y[ki], wherein the hybrid upsample filter provides a higher phase gain than a zero-order type upsample filter at frequencies less
than one kilohertz, and approximately the same attenuation as a first-order type upsample filter around the sample frequency;
and

generate the actuator control signal in response to the second sequence of control samples y[ki].

US Pat. No. 9,058,261

SYSTEMS AND METHODS FOR DETAILED ERROR REPORTING IN DATA STORAGE SYSTEMS

Western Digital Technolog...

1. A method for reporting errors in a data storage system comprising a controller device and a bridge device coupled with
a non-volatile memory storage, the method comprising:
causing execution of a memory access operation spanning a plurality of memory elements in the non-volatile memory storage,
wherein execution of the memory access operation comprises: upon encountering a failure in a memory element, continuing executing
the memory access operation on one or more memory elements following the memory element where the failure has been encountered
until the memory access operation is completed; and

receiving an error report comprising, for each memory element on which the memory access operation has been executed, a status
of executing the memory access operation on the memory element, wherein the error report comprises a status of executing the
memory access operation on at least one memory element subsequent to the memory element where the failure has been encountered,

wherein the method is performed by the controller device.

US Pat. No. 9,214,175

DATA STORAGE DEVICE CONFIGURING A GAIN OF A SERVO CONTROL SYSTEM FOR ACTUATING A HEAD OVER A DISK

Western Digital Technolog...

1. A data storage device comprising:
a first disk surface comprising servo data defining servo tracks at a first radial density;
a first head;
a voice coil motor (VCM) configured to actuate the first head over the first disk surface; and
control circuitry comprising a servo control system configured to control the VCM, the control circuitry configured to:
execute a load operation to load the first head over the first disk surface;
evaluate a back electromotive force (BEMF) voltage generated by the VCM during the load operation to generate an estimated
distance traveled;

detect the servo data on the first disk surface;
detect an initial servo track during the load operation based on the detected servo data to generate a measured distance traveled;
and

configure a gain of the servo control system based on the estimated distance traveled and the measured distance traveled.

US Pat. No. 9,268,682

METHODS, DEVICES AND SYSTEMS FOR PHYSICAL-TO-LOGICAL MAPPING IN SOLID STATE DRIVES

Skyera, LLC, San Jose, C...

23. A method of controlling a data storage device comprising a volatile memory and a plurality of non-volatile memory devices,
each of the plurality of non-volatile devices being configured to store a plurality of physical pages, each of the plurality
of physical pages being stored at a predetermined physical location within the plurality of non-volatile devices, the method
comprising:
storing data in a plurality of logical pages (L-Pages), each of the plurality of L-Pages being associated with an L-Page number
that is configured to enable a controller to logically reference data stored in one or more of the physical pages;

maintaining a logical-to-physical address translation map in the volatile memory, the translation map being configured to
enable determination of a physical location, within one or more of the physical pages, of the data stored in each L-Page,
wherein an entry in the logical-to-physical address translation map includes an association between an L-page number and at
least one of a length of the L-page or a size of error correcting code bits to be applied to the entry in the logical-to-physical
address translation map;

maintaining a plurality of journals defining physical-to-logical correspondences in the plurality of non-volatile memory devices,
each of the plurality of journals being associated with a journal number, each journal covering a pre-determined range of
physical pages and each comprising a plurality of journal entries, each entry being configured to associate one or more physical
pages to each L-Page; and

reading the plurality of journals upon startup and rebuilding the logical-to-physical address translation map stored in volatile
memory based upon the read entries in the plurality of journals.

US Pat. No. 9,058,834

POWER ARCHITECTURE FOR LOW POWER MODES IN STORAGE DEVICES

Western Digital Technolog...

1. A power control device comprising:
an always-on-domain (AOD) comprising:
control logic circuitry for controlling power from a power source;
a plurality of load switches; and
a plurality of bias current generators; and
a plurality of functional blocks,
wherein the control logic circuitry is configured to:
receive a signal to go into a lower power state;
initiate a shut-down sequence of the load switches and the bias current generators of the AOD, to disable circuitry outside
of the AOD, including the functional blocks of the power control device and loads controlled by the power control device;
and

operate in a low power state to detect a wake-up signal.

US Pat. No. 9,058,851

INFORMATION-STORAGE DEVICE INCLUDING AN OXYGEN ABSORBING DEVICE

Western Digital Technolog...

1. An information-storage device, comprising:
an information-storage medium;
a transducer operable to write information in, and operable to read information from, said information-storage medium;
a sealed enclosure enclosing said information-storage medium and said transducer in an interior space of said enclosure containing
an atmosphere comprising a gas mixture including a substantially inert gas and oxygen gas having a molar concentration between
about 0% and about 10%, said enclosure including:

a base;
a cover; and,
a seal that joins said cover to said base; and,
an oxygen absorbing device operable to remove a substantial portion of said oxygen gas from said atmosphere, including an
oxygen absorbent material comprising oxygen-deficient cerium oxide, CeO2-x, where 0

US Pat. No. 9,183,889

DISK DRIVE HAVING A TOP COVER CHANNEL VENTED TO A CENTRAL CAVITY VIA A HOLE THROUGH A BOTTOM LAND

Western Digital Technolog...

1. A disk drive comprising:
a disk drive base comprising a central cavity surrounded by a peripheral wall; and
a top cover attached to the disk drive base and disposed over the central cavity to define a disk drive enclosure, the top
cover having a central top face that defines a central top face plane;

a disk rotatably attached to the disk drive base within the central cavity and disposed within the disk drive enclosure; and
a foil seal adhered to the central top face;
wherein the central top face of the top cover includes a first channel that has a bottom land that is depressed towards the
disk relative to the central top face plane,

wherein the foil seal covers the first channel,
and wherein the first channel is vented to the central cavity by a hole through the bottom land of the first channel.

US Pat. No. 9,354,955

PARTIAL GARBAGE COLLECTION FOR FAST ERROR HANDLING AND OPTIMIZED GARBAGE COLLECTION FOR THE INVISIBLE BAND

Western Digital Technolog...

1. A method for managing garbage collection of memory locations in a data storage device (DSD) comprising a plurality of dies,
each die comprising a plurality of memory blocks, the method comprising:
selecting a physical region of memory to be garbage collected, the selected physical region being a subset of a block management
region; and

garbage collecting the selected physical region of memory, the garbage collecting comprising:
determining one or more journals corresponding to the selected physical region, the one or more journals comprising transaction
entries indicating what logical data are written to memory locations in the selected physical region;

determining whether the memory locations within the physical region of memory contain valid data based on a comparison of
information in the one or more journals and a mapping table;

if valid data exists, copying valid data into memory locations in memory regions other than the selected physical region of
memory; and

alternating garbage collecting on an invisible band journal with garbage collecting the selected physical region of memory
associated with one or more data band journals, wherein garbage collecting on the invisible band journal comprises mapping
information transaction entries recording what logical data are mapped to a location designed for denoting that logical data
has been invalidated,

wherein the selected physical region of memory is erased when the block management region is erased.

US Pat. No. 9,214,963

METHOD AND SYSTEM FOR MONITORING DATA CHANNEL TO ENABLE USE OF DYNAMICALLY ADJUSTABLE LDPC CODING PARAMETERS IN A DATA STORAGE SYSTEM

Western Digital Technolog...

1. A data storage system, comprising:
a non-volatile memory array comprising a plurality of memory pages; and
a controller coupled to the non-volatile memory array through a data channel, the controller being configured to:
use a first set of low-density parity-check (LDPC) coding parameters to encode at a first code rate first data to be stored
into the non-volatile memory array through the data channel, wherein the first set of LDPC coding parameters define a characteristic
of a first matrix used to encode the first data;

detect a change in a condition of the data channel; and
in response to said detecting, use a second set of LDPC coding parameters to encode at a second code rate different from the
first code rate second data to be stored into the non-volatile memory array through the data channel,

wherein the second set of LDPC coding parameters define a characteristic of a second matrix used to encode the second data
and are different from the first set of LDPC coding parameters.

US Pat. No. 9,304,709

HIGH PERFORMANCE SYSTEM PROVIDING SELECTIVE MERGING OF DATAFRAME SEGMENTS IN HARDWARE

Western Digital Technolog...

1. A method of writing data to a range of logical blocks in a storage medium, the method comprising:
receiving a command comprising a starting logical block address, a value indicating a range of logical block addresses to
be written, and a logical block of data;

storing the logical block of data in a first temporary storage;
generating a logical page by duplicating the logical block of data a plurality of times corresponding to a number of logical
blocks comprising a logical page and transporting the generated logical page to a second temporary storage and storing the
generated logical page in the second temporary storage;

writing the generated logical page from the second temporary storage into the storage medium beginning from the starting logical
block address, wherein the writing the generated logical page is performed as a background task to other write operations
involving merging; and

performing a read-modify-write operation if the first write operation does not begin on a logical page boundary or the last
write operation does not end on a logical page boundary.

US Pat. No. 9,251,839

DATA STORAGE DEVICE WITH OVERVOLTAGE PROTECTION

Western Digital Technolog...

10. A data storage device comprising:
spindle motor circuitry;
Voice Coil Motor (VCM) circuitry; and
a power device coupled to a host power supply via first and second host supply lines and coupled to the spindle motor circuitry
and the VCM circuitry, the power device comprising:

first and second voltage rails;
a first isolation circuit; and
control circuitry;
a second isolation circuit coupled to the second host supply line between the host power supply and the power device; and
a third isolation circuit coupled to the first host supply line between the host power supply and the power device;
wherein the power device is operable to receive a first supply voltage on the first voltage rail via the first host supply
line and a second supply voltage on the second voltage rail via the second host supply line and provide the first supply voltage
to the spindle motor circuitry and the VCM circuitry via the first isolation circuit;

wherein the control circuitry is further operable to:
monitor the first and second voltage rails for an overvoltage event; and
when the overvoltage event is detected:
control the first isolation circuit to disconnect the spindle motor circuitry and the VCM circuitry from the first voltage
rail;

control the second isolation circuit to disconnect the second host supply line from the power device; and
control the third isolation circuit to disconnect the first host supply line from the power device.

US Pat. No. 9,384,088

DOUBLE WRITING MAP TABLE ENTRIES IN A DATA STORAGE SYSTEM TO GUARD AGAINST SILENT CORRUPTION

Western Digital Technolog...

1. A method for writing data in a data storage device using a control unit, the method comprising:
writing, by the control unit, data to a physical memory location in a non-volatile memory;
sending, by the control unit, a first update request corresponding to the data to write a physical address of the physical
memory location to a location in a volatile memory corresponding to a logical address of the data; and

sending, by the control unit, a second update request corresponding to the data to write the physical address of the physical
memory location to the location in the volatile memory corresponding to the logical address of the data, thereby reducing
a probability of writing the physical address of the physical memory location to a wrong location in the volatile memory;

wherein the physical address of the physical memory location is written with appended error detection code information, and
the error detection code information is determined based on the logical address of the data.

US Pat. No. 9,507,523

METHODS, DEVICES AND SYSTEMS FOR VARIABLE SIZE LOGICAL PAGE MANAGEMENT IN A SOLID STATE DRIVE

Western Digital Technolog...

1. A data storage device, comprising:
an array of flash memory devices comprising a plurality of blocks, each comprising a plurality of physical pages;
a controller coupled to the array of memory devices and configured to program and read data from the array of memory devices
responsive to data access commands from a host, wherein the controller is configured to:

store data in a plurality of logical pages (L-Pages) of different sizes, each of the plurality of L-Pages being associated
with an L-Page number that is configured to enable the host to logically reference data stored in one or more of the plurality
of physical pages;

maintain a logical-to-physical address translation map configured to enable the controller to determine a location, within
one or more physical pages, of the data referenced by each L-Page number,

wherein the translation map comprises a plurality of mapping entries arranged by L-Page numbers, each mapping entry comprising:
a complete starting physical address of an L-Page within one of the plurality of physical pages, and
a size of the L-Page associated with the L-Page number of the mapping entry;
maintain a system journal (S-Journal) that includes a plurality of journal entries, wherein each of the plurality of journal
entries is configured to associate one or more of the plurality of physical pages to each of the plurality of L-pages; and

create a journal entry directly into one of the plurality of journals each time a logical page in the logical-to-physical
address translation map is updated.

US Pat. No. 9,117,482

HYBRID DRIVE CHANGING POWER MODE OF DISK CHANNEL WHEN FREQUENCY OF WRITE DATA EXCEEDS A THRESHOLD

Western Digital Technolog...

1. A hybrid drive comprising:
a disk channel comprising a head actuated over a disk, the disk comprising a plurality of data sectors;
a non-volatile semiconductor memory (NVSM) comprising a plurality of memory segments; and
control circuitry operable to:
receive write commands from a host, wherein the write commands comprise write data; and
when a frequency of the write data of the write commands received from the host exceeds a first threshold, change an operating
mode of the disk channel to change a power consumption rate of the disk channel, wherein the frequency of write data is based
on an amount of write data received over a time interval.

US Pat. No. 9,245,540

VOICE COIL MOTOR TEMPERATURE SENSING CIRCUIT TO REDUCE CATASTROPHIC FAILURE DUE TO VOICE COIL MOTOR COIL SHORTING TO GROUND

Western Digital Technolog...

20. A data storage device (DSD), comprising:
an electrical circuit, comprising:
a plurality of field effect transistors (FETs) configured as an H-bridge circuit;
one or more temperature sensors integrated with each of the plurality of FETs; and
a control unit configured to:
receive temperature signals from the one or more temperature sensors;
compare the received temperature signals from the one or more temperature sensors of each of the plurality of FETs to received
temperature signals from the one or more temperature sensors of every other one of the plurality of FETs;

in response to a variation in the received temperature signals from the one or more temperature sensors of any one of the
plurality of FETs greater than a predetermined amount compared to the received temperature signals from the one or more temperature
sensors of any other one of the plurality of FETs, render the plurality of FETs inoperative; and

in response to the variation in the received temperature signals exceeding the predetermined amount, record an over-temperature
event.

US Pat. No. 9,099,159

DISK DRIVE GENERATING QUALITY METRIC MAP FOR A DATA TRACK WHILE IN DIFFERENT CONFIGURATIONS

Western Digital Technolog...

1. A disk drive comprising:
a disk comprising a plurality of servo tracks defined by servo sectors;
a head actuated over the disk; and
control circuitry comprising a read channel, the control circuitry operable to:
define a plurality of data tracks relative to the servo tracks, wherein each data track comprises at least one data segment
between consecutive servo sectors;

configure the read channel into a read mode in order to first read a first data segment of a first data track;
during the first read, generate a quality metric at periodic points along the first data segment;
after the first read, configure the read channel into a non-read mode for a predetermined interval;
after the predetermined interval, configure the read channel into the read mode in order to second read the first data segment
of the first data track; and

during the second read, generate the quality metric at the periodic points along the first data segment,
wherein during the predetermined interval the control circuitry is further operable to seek the head away from the first data
track by at least one data track and then seek the head back to the first data track.

US Pat. No. 9,286,176

SELECTIVE SKIPPING OF BLOCKS IN AN SSD

Western Digital Technolog...

1. A solid state drive (SSD), comprising:
a plurality of solid state memory devices, wherein one of the plurality of solid state memory devices comprises a plurality
of memory blocks arranged in a plurality of planes;

a storage; and
an SSD controller configured to:
write data to the plurality of memory blocks in a predefined sequence,
detect a defective memory block in one of the plurality of memory blocks,
mark the detected memory block as defective and store an address of a next non-defective memory block,
in response to data to be written to the marked memory block, skip the marked memory block and write the data to the next
non-marked memory block, and

in response to detecting a weak memory block, periodically mark the weak memory block as defective for a predetermined number
of write cycles and then clear the mark.

US Pat. No. 9,236,085

METHOD AND APPARATUS FOR PERFORMING A DEFECT PROCESS ON A DATA STORAGE DEVICE

Western Digital Technolog...

1. A magnetic data storage device comprising:
a magnetic data storage disk configured to store a defect log comprising one or more defect records of defects on the disk,
wherein each of the defect records spans multiple words and comprises chunks that are word-aligned, at least one of the chunks
comprising one or more record fields; and

a controller configured to read the defect records on a word basis and configured to select a single chunk with which to search
the defect records for a target defect record, and to search record fields located in the selected single chunk at a same
time to determine whether the target defect record matches a defect record in the defect log.

US Pat. No. 9,196,302

ELECTRONIC SYSTEM WITH MEDIA MAINTENANCE MECHANISM AND METHOD OF OPERATION THEREOF

Western Digital Technolog...

1. An apparatus comprising:
a media includes a lube layer on a surface;
a memory for storing operational data;
a first head over the media; and
control circuitry, coupled to the first head, configured to:
position the first head over a first surface of the media; and
perform a leveling of the lube layer on the surface by at least:
flushing the operational data from the memory to a first reserved location of a plurality of reserved locations on the media,
the flushing based at least in part on a timer;

resetting the timer; and
repositioning the head and flushing the operational data from the memory to a next reserved location of the plurality of the
reserved locations on the media, the flushing based at least in part on the timer.

US Pat. No. 9,180,563

DE-SWAGE MACHINE FOR REMOVAL OF A HEAD FROM A HEAD STACK ASSEMBLY AND METHOD OF USING THE SAME

Western Digital Technolog...

1. A de-swage machine for removal of a head of a head stack assembly comprising:
a tooling unit configured to receive a head stack assembly comprising a plurality of heads and an indicia;
a blade module configured to remove a head from the head stack assembly;
an indicia reader configured to read the indicia; and
a controller configured to select and remove a head from the head stack assembly by at least:
reading the indicia using the indicia reader;
transmitting the indicia to a database;
receiving head stack assembly information corresponding to the indicia from the database;
selecting the head for removal based on the head stack assembly information; and
removing the selected head using the blade module.

US Pat. No. 9,286,925

DATA STORAGE DEVICE WRITING MULTIPLE BURST CORRECTION VALUES AT THE SAME RADIAL LOCATION

Western Digital Technolog...

1. A data storage device comprising:
a disk comprising a plurality of servo tracks defined by servo bursts;
a head; and
control circuitry configured to:
position the head based on a first target radial location over the disk and generate a first burst correction value by reading
at least one of the servo bursts;

position the head based on a second target radial location over the disk and generate a second burst correction value by reading
at least one of the servo bursts;

position the head based on a third target radial location over the disk and write the first burst correction value and the
second burst correction value at the third target radial location; and

servo the head over the disk by reading the first and second burst correction values,
wherein the first, second and third target radial locations are different from one another.

US Pat. No. 9,230,593

DATA STORAGE DEVICE OPTIMIZING SPINDLE MOTOR POWER WHEN TRANSITIONING INTO A POWER FAILURE MODE

Western Digital Technolog...

1. A data storage device comprising:
a disk;
a spindle motor configured to rotate the disk, wherein the spindle motor comprises a plurality of windings;
a head actuated over the disk; and
control circuitry powered by a supply voltage, the control circuitry configured to:
commutate the windings based on a commutation sequence while applying a driving voltage to each winding, wherein the driving
voltage comprises an operating amplitude during normal operation; and

when the supply voltage falls below a threshold, configure the spindle motor into a power generator by at least reducing the
amplitude of the driving voltage to substantially zero and then incrementally increasing the amplitude of the driving voltage
by at least two steps toward the operating amplitude.

US Pat. No. 9,250,994

NON-BINARY LOW-DENSITY PARITY CHECK (LDPC) DECODING USING TRELLIS MAXIMIZATION

Western Digital Technolog...

1. A data storage system, comprising:
a solid-state memory array configured to store a plurality of encoded data units; and
a controller configured to decode at least one encoded data unit of the plurality of encoded data units by updating a check
node of a plurality of check nodes associated with a parity check matrix, the controller configured to update the check node
by:

identifying first and second sets of variable nodes in a plurality of variable nodes associated in the parity check matrix
with the check node;

constructing a trellis based on the second set of variable nodes and using the trellis to determine a message;
based at least in part on the message, determining a first set of messages to be sent from the check node to the first set
of variable nodes; and

determining a second set of messages to be sent from the check node to each variable node in the second set of variable nodes.

US Pat. No. 9,230,585

PER WEDGE PREHEAT DFH TO IMPROVE DATA STORAGE DEVICE PERFORMANCE

Western Digital Technolog...

1. A data storage device comprising:
a disk comprising a plurality of tracks, each track comprising a plurality of data sectors and a plurality of servo sectors;
a spindle motor for rotating the disk;
a had actuated radially over the disk, the head comprising a dynamic fly height (DFH heater; and
control circuitry configured to:
position the head over one of the tracks;
determine a number of servo sectors to pass under the head before a target location over the track is reached;
apply an initial amount of power to the DFH heater that is dependent at least m part on the determined number of servo sectors;
and

decrease the initially-applied amount of power before the target location comes under the head until a predetermined target
power is reached.

US Pat. No. 9,129,138

METHODS AND SYSTEMS FOR A PORTABLE DATA LOCKER

Western Digital Technolog...

1. A method of binding a file to an external drive, said method comprising:
saving a file to an external drive, wherein the file is bound to the external drive to restrict the file from being moved
to another storage location in an unauthorized manner;

determining when the external drive has been coupled to a computer; and
restricting access by the computer to the file based on program code that is installed by the external drive to the computer
and that executes on the computer, wherein the program code is configured to at least restrict the computer from copying and
saving at least a portion of the file to a location other than the external drive, and wherein the program code is configured
to intercept file system commands of applications running on the computer.

US Pat. No. 9,268,499

HYBRID DRIVE MIGRATING HIGH WORKLOAD DATA FROM DISK TO NON-VOLATILE SEMICONDUCTOR MEMORY

Western Digital Technolog...

1. A hybrid drive comprising:
a disk;
a head actuated over the disk;
a non-volatile semiconductor memory (NVSM); and
control circuitry operable to:
receive a plurality of access commands from a host including a plurality of disk access commands and a plurality of NVSM access
commands, wherein the disk access commands include a disk read command;

generate a disk command queue operable to store the disk access commands;
estimate a first execution time needed to execute the disk access commands in the disk command queue;
detect a high workload of disk access commands when the first execution time exceeds a first threshold; and
when the high workload is detected, migrate data of the disk read command to the NVSM because the disk read command is in
the disk command queue when the high workload of disk access commands is detected.

US Pat. No. 9,269,393

ELECTRONIC SYSTEM WITH DATA REFRESH MECHANISM AND METHOD OF OPERATION THEREOF

Western Digital Technolog...

1. An apparatus comprising:
a media;
a head configured to write data on the media;
a read channel, coupled to the head, configured to detect servo data from the media; and
control circuitry, coupled to the read channel, configured to:
generate a position error signal (PES), associated with a write operation of an aggressor track, from the servo data,
compare a first threshold to the PES for detecting a write unsafe condition,
compare a second threshold, within the first threshold, to the PES for detecting a write squeeze condition, and
control a refresh operation of a victim track based on at least one of the comparisons.

US Pat. No. 9,069,475

HYBRID DRIVE SELECTIVELY SPINNING UP DISK WHEN POWERED ON

Western Digital Technolog...

1. A hybrid drive comprising:
a disk;
a head actuated over the disk;
a non-volatile semiconductor memory (NVSM); and
control circuitry operable to boot the hybrid drive by:
transferring boot data from the NVSM to a host; and
after transferring at least seventy percent of the boot data to the host, begin spinning up the disk prior to receiving an
access command from the host to access the disk.

US Pat. No. 9,472,222

VIBRATION MITIGATION FOR A DATA STORAGE DEVICE

Western Digital Technolog...

1. A Data Storage Device (DSD), comprising:
a disk for storing data;
a solid-state memory for storing data, the solid-state memory including a cache segment and a dedicated segment for storing
data during a vibration condition; and

a controller configured to:
receive an input indicating the vibration condition;
receive a write command from a host to store data in the DSD;
store at least a portion of the data for the write command in the dedicated segment of the solid-state memory based on the
received input indicating a vibration condition for the DSD;

determine whether an indication from the host indicates that data of the write command is to be stored in the solid-state
memory;

store the data of the write command during the vibration condition in the cache segment of the solid-state memory if it is
determine that the indication from the host indicates that data of the write command is to be stored in the solid-state memory;
and

store the data of the write command during the vibration condition in the dedicated portion of the solid-state memory if it
is determined that the indication from the host does not indicate that data of the write command is to be stored in the solid-state
memory.

US Pat. No. 9,286,079

CACHE OPTIMIZATION OF A DATA STORAGE DEVICE BASED ON PROGRESS OF BOOT COMMANDS

Western Digital Technolog...

1. A method for operating a mass storage device, said method comprising:
detecting power-up of a host device connected to a mass storage device over a communications interface;
providing boot code to the host device over the communications interface in response to said detecting the power-up;
setting a cache of the mass storage device to a boot caching mode;
receiving, by the mass storage device, data storage access commands from the host device;
monitoring a command queue configured to buffer the data storage access commands;
determining that a depth of the command queue has increased to a value greater than one;
determining a transition from a boot process to normal operations by the host device based at least in part on the increase
of the command queue depth; and

setting the cache of the mass storage device to an operational mode based on the transition.

US Pat. No. 9,251,844

WATERFALL METHOD AND APPARATUS FOR A DATA STORAGE DEVICE READ SYSTEM

Western Digital Technolog...

1. A magnetic storage medium reader system for a data storage device, comprising:
at least a first reader system and a second reader system, the first reader system including a first reader element, and the
second reader system including a second reader element;

a first head including the first reader element and the second reader element; and
control circuitry reconfigured during manufacturing of the magnetic storage medium reader system to cause the second reader
system, but not the first reader system, to read a magnetic storage medium, the first reader system determined during the
manufacturing to provide less than a predetermined performance or to be nonfunctioning.

US Pat. No. 9,141,531

DATA FLUSH FROM CACHE TO DISK BASED ON TRACK LIMIT

Western Digital Technolog...

1. A disk drive comprising:
a disk;
a head actuated over the disk;
a volatile semiconductor memory (VSM);
a command queue; and
control circuitry to:
receive a plurality of write commands from a host;
store the plurality of write commands in the command queue;
store write data for the plurality of write commands in the VSM; and
flush, from the VSM to the disk, a portion of the write data corresponding to a predetermined number of tracks, wherein the
predetermined number of tracks comprises a limit on a number of tracks that are accessed when flushing the portion of the
write data and wherein the predetermined number of tracks is based on a revolution time of the disk and one or more other
performance measurements of the disk.

US Pat. No. 9,076,471

FALL DETECTION SCHEME USING FFS

Western Digital Technolog...

1. A disk drive comprising:
a disk;
a head; and
control circuitry comprising a servo control system operable to actuate the head over the disk, the control circuitry configured
to:

determine a magnitude of acceleration readings, the acceleration readings involving at least three degrees of freedom,
confirm a free fall when a magnitude of the acceleration readings is less than a first threshold, and
confirm a tilt drop when the magnitude is between the first and a second threshold.

US Pat. No. 9,064,542

SCHEDULED LOAD OF HEADS TO REDUCE LUBRICANT MIGRATION ON POLE TIP AND DECREASE TIME TO READY

Western Digital Technolog...

1. A disk drive comprising:
a disk media;
a head; and
control circuitry comprising a servo control system configured to actuate the head for reduction of lubricant migration, the
control circuitry configured to:

unload the head onto a ramp for a period of time based on a time constant;
load the head onto the disk after the period of time has elapsed;
repeatedly measure head-media spacing (HMS) until HMS measurements become constant within a predetermined range; and
unload the head when the HMS measurements become constant within a predetermined range.

US Pat. No. 9,471,242

EARLY DE-ALLOCATION OF WRITE BUFFER IN AN SSD

Western Digital Technolog...

1. A solid state drive controller comprising:
a controller front end configured to receive a write command including a plurality of logical segments of data;
a buffer, coupled to the controller front end, configured to accumulate the plurality of logical segments of data; and
a memory controller configured to initiate a transfer of the accumulated logical segments of data from the buffer to a temporary
register in a nonvolatile solid state memory when the buffer accumulates enough data to program a predetermined number of
physical segments of data in the nonvolatile solid state memory;

wherein the memory controller is configured to initiate a deallocation of the buffer after the temporary register completes
a reception of the accumulated data from the buffer.

US Pat. No. 9,147,428

DISK DRIVE WITH IMPROVED SPIN-UP CONTROL

Western Digital Technolog...

1. A disk drive comprising:
a head actuated over a disk;
a spindle motor operable to rotate the disk; and
control circuitry operable to:
measure a rotation speed of the spindle motor;
generate a gain as a function of the measured rotation speed, wherein the function comprises a polynomial having a degree
greater than one; and

spin-up the spindle motor based on the gain.

US Pat. No. 9,275,677

HARD DISK DRIVE TOP COVER REMOVAL

Western Digital Technolog...

1. A method for removing a top cover of a hard disk drive, the method comprising:
securing a hard disk drive in a nest assembly;
pressing a clamp coupled to the nest assembly against a top cover of the secured hard disk drive such that the top cover maintains
contact with a hard drive body of the hard disk drive;

removing a screw fastening the top cover to the hard drive body at a screw location of the top cover and the hard drive body;
rotating the secured hard disk drive from a first position to a second position;
purging and evacuating, with a purge and vacuum assembly, particles from the screw location of the pressed top cover and the
hard drive body of the hard disk drive in the second position;

releasing the top cover; and
removing, with the purge and vacuum assembly, the released top cover from the hard drive body.

US Pat. No. 9,390,762

METHOD FOR ASSEMBLING A STORAGE DEVICE

Western Digital Technolog...

1. A method of assembling an external storage device, the method comprising:
providing an external cover to a storage device assembly fixture, the external cover having a first face and a second face
generally parallel to and opposing the first face, the first face coupled to the second face at a back end of the external
cover, the first face defining a first edge at a front end of the external cover opposite the back end, and the second face
defining a second edge at the front end;

placing the external cover within the storage device assembly fixture;
engaging the first edge of the external cover with a first finger of the storage device assembly fixture;
engaging the second edge of the external cover with a second finger of the storage device assembly fixture;
pivoting the second finger away from the first finger to move the second face of the external cover away from the first face
of the external cover; and

inserting a storage device between the first face and the second face of the external cover.

US Pat. No. 9,269,386

DATA STORAGE DEVICE ON-LINE ADAPTING DISTURBANCE OBSERVER FILTER

Western Digital Technolog...

1. A data storage device comprising:
a disk comprising tracks defined by servo sectors;
a head; and
control circuitry configured to:
measure a location of the head over the disk based on the servo sectors;
generate a position error signal (PES) representing a difference between a target location for the head and the measured location
for the head;

generate an actuator control signal (ACS) in response to the PES;
generate a disturbance compensation signal (DCS) based on the PES and the ACS;
filter the DCS with a disturbance observer filter;
adjust the ACS based on an output of the disturbance observer filter;
actuate the head over the disk based on the adjusted ACS;
filter the DCS with a plurality of band-pass filters;
filter an output of one of the band-pass filters with a peak detection filter configured to detect a peak frequency corresponding
to a peak in a frequency response of the band-pass filter; and

adjust the disturbance observer filter based on the peak frequency.

US Pat. No. 9,337,613

CHIP ON SUBMOUNT CARRIER FIXTURE

Western Digital Technolog...

1. A chip-on-submount-assembly (COSA) testing system comprising:
a first non-conductive layer having a plurality of through holes and a first alignment pin hole pair;
a second conductive layer having a plurality of first openings and a second alignment pin hole pair, the second conductive
layer being disposed over the first non-conductive layer with each of the plurality of first openings overlaying one of the
plurality of through holes; and

a third non-conductive layer having a third alignment pin hole pair and a plurality of second openings that are larger than
the plurality of first openings, the third non-conductive layer being disposed over the second conductive layer with each
of the plurality of second openings overlaying one of the plurality of first openings; and

a pair of alignment pins positioned through the first alignment pin hole pair, second alignment pin hole pair, and third alignment
pin hole pair,

wherein the plurality of first openings and the plurality of second openings form a plurality of pockets with a seat on the
second conductive layer.

US Pat. No. 9,330,715

MAPPING OF SHINGLED MAGNETIC RECORDING MEDIA

Western Digital Technolog...

1. A method for mapping out restricted areas on at least one disk of a data storage device (DSD), wherein the at least one
disk includes overlapping tracks with a plurality of sectors for storing data, the method comprising:
providing a first addressing for the plurality of sectors on the at least one disk;
detecting defective sectors of the plurality of sectors;
mapping out the defective sectors from the first addressing;
calculating a restricted area for a guardband of sectors for a shingle zone of overlapping tracks or for a write log; and
mapping out the restricted area from a second addressing.

US Pat. No. 9,743,547

SWITCHABLE MECHANICAL CONSTRAINT FOR ELECTRICAL CONNECTOR WITH COMPLIANT MOUNTING

WESTERN DIGITAL TECHNOLOG...

1. A system, comprising:
a sled comprising:
a base,
an electrical connector positioned within and movable relative to the base; and
a locking mechanism positioned within the base and movable, relative to the base and the electrical connector, between a locked
position and an unlocked position, wherein in the locked position the locking mechanism restricts movement of the electrical
connector in at least one degree of freedom relative to the base, and in the unlocked position the locking mechanism does
not restrict movement of the electrical connector in the at least one degree of freedom relative to the base; and

a data storage device positioned within the base and co-movably coupled to the electrical connector.

US Pat. No. 9,281,009

DATA STORAGE DEVICE EMPLOYING VARIABLE SIZE INTERLEAVE WRITTEN TRACK SEGMENTS

Western Digital Technolog...

1. A data storage device comprising:
a disk comprising a plurality of data tracks;
a head; and
control circuitry configured to:
encode data into a first number of codewords;
interleave write the first number of codewords to a first segment of a first data track;
encode data into a second number of codewords; and
interleave write the second number of codewords to a second segment of the first data track;
wherein the first number is different than the second number and a size of the first segment is different than a size of the
second segment.

US Pat. No. 9,171,568

DATA STORAGE DEVICE PERIODICALLY RE-INITIALIZING SPINDLE MOTOR COMMUTATION SEQUENCE BASED ON TIMING DATA

Western Digital Technolog...

1. A data storage device comprising:
a disk comprising timing data;
a spindle motor configured to rotate the disk, wherein the spindle motor comprises a plurality of windings;
a head actuated over the disk; and
control circuitry configured to:
initialize a phase of a commutation controller based on the timing data on the disk;
drive a commutation sequence of the commutation controller based on the timing data on the disk, wherein the commutation controller
is configured to commutate the windings based on the commutation sequence; and

re-initialize the phase of the commutation controller based on the timing data on the disk, thereby compensating for a cumulative
phase error when driving the commutation sequence based on the timing data on the disk.

US Pat. No. 9,274,978

MIGRATION OF ENCRYPTED DATA FOR DATA STORAGE SYSTEMS

Western Digital Technolog...

1. A data storage system comprising:
non-volatile memory (NVM) configured to store data in a plurality of memory data units, a memory data unit corresponding to
a unit of storage in the NVM, wherein at least some memory data units have a different format; and

a controller configured to:
retrieve from the NVM data stored in a first memory data unit, the first memory data unit further storing metadata associated
with the data, wherein the data is encrypted and the metadata is not encrypted, and

using the metadata and without decrypting the data, migrate the data from the first memory data unit to a second memory data
unit, the format of the second memory data unit being different than the format of the first memory data unit,

wherein migrating the data from the first memory data unit to the second memory data unit causes at least some data stored
in the first memory data unit to become invalid, and

wherein migrating the data from the first memory data unit to the second memory data unit causes improved performance or reliability
of the data storage system,

wherein the NVM comprises a non-volatile solid-state memory array and a magnetic storage, wherein a physical storage unit
of the non-volatile solid-state memory array is larger in size than a physical storage unit of the magnetic storage, and wherein
the controller is further configured to format the data to be stored in a physical storage unit of a different size in performing
the migration.

US Pat. No. 9,268,649

DISK DRIVE WITH RECENT WRITE STREAMS LIST FOR DATA REFRESH DETERMINATION

Western Digital Technolog...

11. A method of operating a disk drive, the disk drive comprising a disk, the disk comprising a plurality of refresh regions,
each refresh region comprising a range of logical block addresses (LBAs), a memory separate from the plurality of refresh
regions on the disk, the memory storing a recent write streams list comprising one or more entries, each entry representing
an LBA stream, and a head actuated radially over the disk to write data to and read data from the disk, the method comprising:
executing a write command comprising one or more LBAs;
determining whether the one or more LBAs in the write command are sequential to an entry in the recent write streams list;
modifying an entry in the recent write streams list when the one or more LBAs in the write command are sequential to the entry;
determining whether the modified entry entirely overlaps a refresh region; and
if it is determined that the modified entry entirely overlaps the refresh region, resetting an associated refresh counter
based on the determination that the modified entry entirely overlaps the refresh region.

US Pat. No. 9,265,171

SELF-ALIGNING BRACKET ASSEMBLY

Western Digital Technolog...

1. A system comprising:
a data storage device;
a fastener; and
a self-aligning bracket assembly mounted on the data storage device for attaching a shock mount to the data storage device
comprising:

an elongate plate having a first side and a second side opposite the first side, the plate comprising:
a first surface on the first side in contact with the data storage device;
a first sunken portion on the first side displaced from the first surface forming an open space between the first surface
and the first sunken portion and thereby forming an open space on the first side between the plate and the data storage device;

a first opening extending through the plate from the second side to the first side at the first sunken portion, the first
opening having a first chamfer formed in the second side of the plate having a head of the fastener positioned therein to
mount and self-align the bracket assembly to the data storage device, the first opening positioned at the first sunken portion
to allow for deflection of the sunken portion upon mounting to the data storage device with the fastener; and

a shock mount extending from the plate.

US Pat. No. 9,251,067

HIGH SPEED TRIM COMMAND PROCESSING IN A SOLID STATE DRIVE

WESTERN DIGITAL TECHNOLOG...

1. A data storage device, comprising:
a plurality of non-volatile memory devices configured to store a plurality of physical pages; and
a controller coupled to the plurality of non-volatile memory devices and configured to:
program data to and read data from the plurality of non-volatile memory devices, the data being stored in a plurality of logical
pages (L-Pages) of non-zero length at a starting address within one of the plurality of physical pages; and

execute a first command to indicate that a first physical location within the plurality of non-volatile memory devices no
longer contains valid data and is now free space by at least:

carrying out a first virtual write operation of a first L-Page of a predetermined length at a first unique address within
a virtual address range that does not correspond to any of the physical pages; and

accounting for an amount of free space gained as a result of executing the first command; and
execute a second command to indicate that a second physical location within the plurality of non-volatile memory devices no
longer contains valid data and is now free space by at least:

carrying out a second virtual write operation of a second L-Page of a predetermined length at a second unique address within
the virtual address range, the first unique address being different from the second unique address; and

accounting for an amount of free space gained as a result of executing the second command.

US Pat. No. 9,250,893

VIRTUALIZED AND AUTOMATED SOFTWARE BUILD SYSTEM

Western Digital Technolog...

1. A software automation build system comprising:
one or more non-transitory source code repositories, the one or more source code repositories comprising:
source code of a software product; and
a configuration specifying a build and test environment, the configuration stored in a configuration file accessible by remote
users to replicate a consistent virtual build and test environment at a remote system for developing and testing code of the
software product at different locations using virtual machines, the configuration file comprising,

a configuration for reconstructing a virtual build machine configured to perform tasks to build the code of the software product
including executing a build job using the reconstructed virtual build machine so that multiple versions of the build and test
environment can be accessed and built virtually.

US Pat. No. 9,236,086

METHODS FOR REDUCING OPERATIONAL LATENCY OF DATA STORAGE SYSTEMS

Western Digital Technolog...

1. A method for writing data to a data storage system, the method comprising:
receiving a reset command for a sequential write pointer of a first zone of a plurality of active zones defined in the data
storage system, the first zone associated with a first pointer;

updating a status of a second zone not within the plurality of active zones to an active status; and
updating a status of the first zone to an inactive status.

US Pat. No. 9,208,808

ELECTRONIC SYSTEM WITH UNLOAD MANAGEMENT MECHANISM AND METHOD OF OPERATION THEREOF

Western Digital Technolog...

1. An apparatus comprising:
a media;
a head assembly over the media;
a head actuation motor coupled to the head assembly;
control circuitry, coupled to the head actuation motor, configured to position the head assembly; and
a head loading ramp, adjacent to the media;
wherein the control circuitry is further configured to:
generate a seek count; and
park the head assembly, off of the media, on the head loading ramp, controlling a speed of the head actuation motor based
on the seek count.

US Pat. No. 9,203,434

SYSTEMS AND METHODS FOR IMPROVED ENCODING OF DATA IN DATA STORAGE DEVICES

Western Digital Technolog...

1. A method of encoding data to be stored in a data storage device, the method comprising:
creating a Low Density Parity Check (LDPC) matrix H from a matrix A and a matrix B, the matrix B comprising a plurality of
sub-matrices bij in a diagonal of the matrix B, wherein i is a row index of the matrix B and j is a column index of the matrix B, wherein the
plurality of sub-matrices bij are full rank, are free of 4-cycles, and have odd row weight and column weight, wherein the plurality of sub-matrices bij form a full rank matrix which includes only elements of a single diagonal of the matrix B, wherein all of the elements of
the matrix B except for bij (i=j) are zero, and wherein the matrix B is a 4×4 matrix, wherein the submatrices bij include b11, b22, b33, and b44, wherein b11 is the sum of five circulants I+I(8)+I(11)+I(15)+I(17), wherein b22 is the sum of five circulants I+I(8)+I(11)+I(15)+I(19), wherein b33 is the sum of five circulants I+I(8)+I(11)+I(15)+I(21), wherein b44 is the sum of five circulants I+I(8)+I(11)+I(15)+I(25), and wherein I(k) notation denotes an identity matrix of order p×p that is left or right circularly shifted by k units;

receiving write data;
encoding the write data on-the-fly using the matrix H; and
writing the encoded write data in a non-volatile storage medium in the data storage device.

US Pat. No. 9,299,372

SWAGE KEY ENABLING SIMULTANEOUS TRANSFER OF TWO HEAD GIMBAL ASSEMBLIES ONTO TWO CORRESPONDING ACTUATOR PIVOT FLEX ASSEMBLY ARMS

Western Digital Technolog...

1. A device for loading a first head gimbal assembly (HGA) and a second HGA onto an actuator pivot flex assembly (APFA) of
a data storage device comprising a hard disk drive, the APFA comprising a first APFA arm defining a first boss hole and a
next adjacent second APFA arm defining a second boss hole, the device comprising:
a support configured to hold the APFA;
a gripper configured to grip the first and the second HGAs and to move the gripped first and second HGAs between the first
and second actuator arms of the held APFA; and

a selectively movable swage key comprising a body portion, the body portion terminating at a distal end in first and second
swage key arms that respectively define first and second proximal portions, first and second distal portions respectively
terminating in first and second free ends, and first and second localized humps disposed between the first and second distal
portions and the first and second proximal portions, respectively,

wherein the swage key is configured to selectively assume a first position such that the first and second distal portions
are respectively disposed between the first and second HGAs, to move to a second position such that the first and second HGAs
are supported by the first and second localized humps, respectively, and such that the first and second HGAs are aligned with
the first and second boss holes and to move to a third position such that the first and second HGAs face the first and second
proximal portions and become seated onto the first and second boss holes, respectively.

US Pat. No. 9,230,579

COMB GRIPPER FOR USE WITH A SHIPPING COMB AND A RAMP IN THE ASSEMBLY OF A DISK DRIVE

Western Digital Technolog...

1. A comb gripper for pushing a comb tower of a shipping comb such that a head stack assembly (HSA) of a disk drive is rotated
and at least one head gimbal assembly (HGA) of the disk drive is coupled to a ramp in the assembly of the disk drive, the
comb gripper comprising:
a first gripper finger comprising a top end and a bottom end, the first gripper finger including a protruding portion at the
bottom end, wherein the protruding portion of the first gripper finger includes a chamfered section that tapers perpendicular
to the first gripper finger;

a second gripper finger; and
an actuator configured to move the first and second gripper fingers, wherein the actuator is configured to move the protruding
portion of the first gripper finger to contact the comb tower and to push the comb tower and the shipping comb such that the
HSA is rotated and the at least one HGA is coupled to the ramp.

US Pat. No. 9,214,174

METHOD OF MANUFACTURING A DISK DRIVE HEAD GIMBAL ASSEMBLY HAVING A FLEXURE TAIL WITH FOLDED BOND PADS

Western Digital Technolog...

1. A method to manufacture a head stack assembly for a disk drive, the method comprising:
attaching a head gimbal assembly that includes a flexure tail having a plurality of flexure bond pads to an actuator that
includes a flexible printed circuit (FPC) with a plurality of FPC bond pads;

folding each of the plurality of flexure bond pads upon itself such that the flexure tail is substantially thicker at each
of the folded flexure bond pads;

aligning the plurality of flexure bond pads with the plurality of FPC bond pads;
introducing an adhesive material that includes a plurality of electrically conductive beads of substantially similar size
between each of the plurality of flexure bond pads and corresponding ones of the plurality of FPC bond pads; and

bringing a thermode tool into contact with the plurality of flexure bond pads after folding, with the thermode tool pressing
the plurality of flexure bond pads against the plurality of FPC bond pads for a period.

US Pat. No. 9,189,392

OPPORTUNISTIC DEFRAGMENTATION DURING GARBAGE COLLECTION

Western Digital Technolog...

1. A method of defragmenting a data storage device, said method comprising:
receiving a read command from a host;
reading a first block of data stored in non-volatile media of a data storage device in response to the read command from the
host;

determining a timing of garbage collection for the first block in response to reading the first block of data;
caching valid data of the first block in response to said determination;
coalescing the valid data;
identifying invalid data in a second block of data stored in the non-volatile media; and
rewriting back the coalesced valid data to the second block.

US Pat. No. 9,117,489

DATA STORAGE DEVICE SCREENING HEADS BY VERIFYING DEFECTS AFTER DEFECT SCAN

Western Digital Technolog...

1. A data storage device comprising:
a disk comprising a plurality of tracks;
a head; and
control circuitry configured to:
defect scan at least one of the tracks and generate a log entry when a defect is detected;
after the defect scan, execute a verify operation for at least two of the detected defects;
count a number of times the verify operation detects a false defect; and
determine whether the head is defective based at least partly on the count.

US Pat. No. 9,383,923

WRITE POINTER MANAGEMENT FOR A DISK DRIVE

Western Digital Technolog...

1. A disk drive comprising:
a disk including a plurality of sectors for storing data;
a non-volatile memory (NVM) for storing data;
a head configured to read data from the disk and write data to the disk; and
a controller configured to:
control the head to sequentially write data sector by sector on the disk, wherein the data written in each sector includes
a write status indicator indicating that data has been written in the sector;

store a write pointer on the disk or the NVM as a check-pointed write pointer, wherein the write pointer corresponds to a
current sector for writing data on the disk; and

during a write pointer recovery process when the check-pointed write pointer is retrievable:
retrieve the check-pointed write pointer from the disk or the NVM;
scan at least one write status indicator in a range of sectors from the sector corresponding to the retrieved check-pointed
write pointer and a last sector to identify the current sector for writing data; and

set the write pointer to correspond to the identified current sector.

US Pat. No. 9,318,144

DISK DRIVE HAVING A SHEET METAL CLAMP WITH A STAMPED ANNULAR PROTRUDING DISK CONTACT FEATURE

Western Digital Technolog...

1. A method to fabricate a disk clamp for a disk drive, the method comprising:
stamping a clamp body portion from a metal sheet;
forming an annular rib that protrudes from the stamped sheet metal body portion, the annular rib including an annular contact
surface, and inner and outer side walls that are each normal to the annular contact surface; and

lapping the annular contact surface;
wherein the lapping reduces but does not eliminate the protrusion of the annular rib from the stamped sheet metal body portion.

US Pat. No. 9,275,927

SELF-HEATING INTEGRATED CIRCUIT

Western Digital Technolog...

1. A method for heating an integrated circuit (IC) including a first drive circuit configured to drive a spindle motor and
a second drive circuit configured to drive a voice coil motor (VCM) coil, the method comprising:
selectively operating the first drive circuit to drive the spindle motor;
selectively operating the second drive circuit to drive the VCM coil; and
selectively operating the first and second drive circuits to heat the IC to a target temperature.

US Pat. No. 9,257,146

DATA STORAGE DEVICE COMPRISING SEQUENCE DETECTOR COMPENSATING FOR INTER-TRACK INTERFERENCE

Western Digital Technolog...

1. A data storage device comprising:
a disk comprising a plurality of data tracks;
a head actuated over the disk; and
control circuitry configured to:
read a first data track to generate a first read signal;
sample the first read signal to generate first read signal samples;
detect a first data sequence based on the first read signal samples;
filter the first data sequence with a target partial response to convert the first data sequence into corresponding first
expected samples;

read a second data track adjacent the first data track to generate a second read signal;
sample the second read signal to generate second read signal samples; and
detect a second data sequence based on the second read signal samples and the first expected samples.

US Pat. No. 9,305,599

STORAGE DEVICE WITH A COVER SUPPORTING PORTION

Western Digital Technolog...

1. A disk drive assembly comprising:
a base;
a voice coil motor assembly (VCM) comprising a VCM cover;
a post extending from the base toward the VCM cover; and
a latch movable mounted on the post such that the post extends there through, wherein the post comprises a cover supporting
portion configured to:

support the VCM cover, and
prevent the VCM cover from compressing the latch and causing the latch to contact both the VCM cover and the base simultaneously
when a load is applied to a portion of the VCM cover above the latch, and

wherein the post is configured to define a gap between the cover supporting portion and the VCM cover such that the VCM cover
and the cover supporting portion only contact when an external load is applied.

US Pat. No. 9,270,296

METHOD AND SYSTEM FOR SOFT DECODING THROUGH SINGLE READ

Western Digital Technolog...

12. A method of decoding data in a data storage system, the method comprising:
performing a first decoding of a first code word based at least in part on data associated with a reading of the first code
word;

detecting a decoding failure associated with the first decoding;
determining bit flip count data associated with a successful decoding of a second code word stored on a same page in the non-volatile
memory array as the first code word;

determining reliability information for decoding the first code word in response to the decoding failure, said determining
based at least in part on the bit flip count data associated with a successful decoding of the second code word; and

performing a second decoding of the first code word based at least in part on the reliability information.

US Pat. No. 9,214,188

ADJUSTING ROTATION SPEED OF DISK TO REDUCE FLY HEIGHT MODULATION WHEN SERVO WRITING IN GAS

Western Digital Technolog...

1. A method of selecting a rotation speed for servo writing a disk of a disk drive, the method comprising:
injecting a gas into a head disk assembly (HDA) comprising the disk;
rotating the disk at a rotation speed and reading data from the disk using a head to generate a read signal comprising a first
frequency oscillation due to reading the data from the disk and a second frequency oscillation due to a fly height of the
head varying as the disk rotates, wherein the first frequency is higher than the second frequency;

measuring an amplitude of the second frequency oscillation to measure a fly height modulation (FHM) of the head;
when the amplitude of the second frequency oscillation exceeds a threshold, adjusting the rotation speed;
servo writing the disk at the adjusted rotation speed;
after servo writing the disk and evacuating the gas from the HDA, rotating the disk at a normal rotation speed lower than
the adjusted rotation speed used for servo writing the disk; and

writing manufacturing data to the disk at the normal rotation speed.

US Pat. No. 9,142,249

DISK DRIVE USING TIMING LOOP CONTROL SIGNAL FOR VIBRATION COMPENSATION IN SERVO LOOP

Western Digital Technolog...

1. A disk drive comprising:
a disk;
a head;
an actuator; and
control circuitry comprising a timing loop configured to generate a clock synchronized to a rotation of the disk and a servo
loop configured to control the actuator to actuate the head over the disk, the control circuitry configured to:

filter a timing signal generated by the timing loop with a pre-compensation filter (PCF) comprising an inverse transfer function
from a delta in a rotation velocity of the disk (??) due to a vibration affecting the disk drive to the timing signal; and

control the actuator to actuate the head over the disk based on an output of the PCF.

US Pat. No. 9,071,574

ACCESS AND CONTROL SYSTEM FOR NETWORK-ENABLED DEVICES

Western Digital Technolog...

1. A process for remotely controlling one or more network-enabled devices by one or more client computers over a public network,
wherein the one or more network-enabled devices are operatively connected within one or more different private networks and
the one or more client computers are operatively connected within one or more other different private networks, at least one
of the private networks being protected by a firewall element, said process comprising:
accessing at least one connection server by at least one of the client computers, said at least one connection server being
operably connected to the public network;

establishing a secure connection between each of the at least one client computers and the at least one connection server,
after which, the at least one connection server establishes a secure connection between the at least one connection server
and each of the network-enabled devices requested to be connected with the at least one client computer, through at least
one device control computer connected with said network-enabled devices, wherein secure, full duplex, persistent communications
are established through the connection server without the need for any of the computers to know or address a private address
of any of the other computers between which the communications take place;

sending control instructions from said at least one client computer to at least one of the connected network-enabled devices,
via the at least one connection server; and

receiving data at said at least one client computer received from said at least one connected network-enabled device via said
at least one connection server.

US Pat. No. 9,293,157

AUTOMATED ACTIVE FEEDBACK SLICE AND VIEW MILLING OF MAGNETIC HEAD CROSS-SECTIONS

Western Digital Technolog...

1. A method, comprising:
obtaining a first micrograph of an air bearing surface of a magnetic head pole;
using the first micrograph, measuring the width of the pole at the air bearing surface and measuring the length of the pole
at the air bearing surface;

if the width of the pole at the air bearing surface is greater than a lower width threshold and less than an upper width threshold,
then performing the steps of:

determining an initial milling region proximal to an outer edge of the pole;
milling the pole within the initial milling region to form a milled surface; and
performing at least one iteration, each iteration comprising:
obtaining an iterative micrograph of the pole at the milled surface;
using the iterative micrograph, measuring a leading bevel angle and a trailing bevel angle of the pole or measuring the length
of the pole at the milled surface; and

if the difference between the leading bevel angle and the trailing bevel angle is greater than a bevel angle threshold or
if the difference between the length of the pole at the milled surface and the length of the pole at the air bearing surface
is greater than a pole length threshold, then milling the pole by a milling amount and performing a next iteration, or else
providing the iterative micrograph for metrology.

US Pat. No. 9,135,205

DATA STORAGE ASSEMBLY FOR ARCHIVE COLD STORAGE

Western Digital Technolog...

9. A hard disk assembly (HDA) comprising:
a platter configured to store data;
a head assembly configured to read data from and write data to the platter;
a motor controller configured to move the head assembly across the platter; and
a circuit board configured to communicate between the HDA and a read channel external to the HDA and shared among a plurality
of HDAs.

US Pat. No. 9,275,741

TEMPERATURE COMPENSATION MANAGEMENT IN SOLID-STATE MEMORY

Western Digital Technolog...

1. A data storage device comprising:
a non-volatile memory array including a plurality of non-volatile memory cells; and
a controller configured to:
receive a signal indicating a temperature of at least a portion of the data storage device;
determine a first offset program verify level associated with a first programming level based at least in part on the temperature;
determine a second offset program verify level associated with a second programming level based at least in part on the temperature;
program a first set of the memory cells of the non-volatile memory array using the first offset program verify level; and
program a second set of the memory cells of the non-volatile memory array using the second offset program verify level;
wherein the first and second offset program verify levels are determined to provide more even distribution of programming
levels, thereby reducing an overall bit error rate associated with the non-volatile memory array.

US Pat. No. 9,099,163

HARD DISK DRIVE (HDD) MOUNTING SYSTEM FOR SHOCK AND VIBRATION

Western Digital Technolog...

1. A damping assembly comprising:
a first mounting sheet having a flexible-sheet structure comprising a first side and a second side opposite the first side
of the first mounting sheet;

at least one elastomeric cushion attached to the second side of the first mounting sheet,
wherein the first side of the mounting sheet of the damping assembly is configured to contact a first surface of a data storage
device enclosure with the first mounting sheet being disposed between the at least one elastomeric cushion and the first surface
of the data storage device enclosure, and

wherein the first mounting sheet further comprises:
a main panel, which contacts the first surface of the data storage device enclosure and
a side panel flexibly connected to the main panel of the first mounting sheet, wherein the side panel of the first mounting
sheet contacts a second surface of the data storage device enclosure, the second surface disposed adjacent to the first surface
of the data storage device enclosure and at an angle with respect to the first surface of the data storage device enclosure,
and

wherein the at least one elastomeric cushion includes a first elastomeric cushion portion attached to the main panel and a
second elastomeric cushion portion attached to the side panel, the first elastomeric cushion portion and the second elastomeric
cushion portion forming a contiguous cushioned area.

US Pat. No. 9,170,938

METHOD AND SYSTEM FOR ATOMICALLY WRITING SCATTERED INFORMATION IN A SOLID STATE STORAGE DEVICE

WESTERN DIGITAL TECHNOLOG...

1. A method of performing an operation in a data storage device, the method comprising:
receiving an atomic write command;
obtaining a plurality of ranges of logical addresses affected by the atomic write command;
for each of the plurality of affected ranges, assigning metadata information to track completion of a write operation performed
at that range;

performing the write operations in the ranges of logical addresses;
updating the metadata information upon completion of the write operations in the ranges; and
deferring an update to a translation map of the data storage device until the metadata information has been updated.

US Pat. No. 10,109,308

DATA STORAGE DEVICE USING PROGRAMMABLE DEGLITCH WINDOW TO DETECT SATURATION OF VCM CURRENT CONTROL

Western Digital Technolog...

1. A data storage device comprising:a disk;
a head;
a voice coil motor (VCM) configured to actuate the head over the disk; and
control circuitry configured to:
use the head to read data recorded on the disk to generate a read signal;
process the read signal to generate a current command signal at a servo sample rate having a servo sample interval;
detect a current flowing through the VCM;
generate a current error signal based on a difference between the current command signal and the detected current flowing through the VCM;
generate an analog command signal based on the current error signal;
apply the analog command signal to the VCM in order to actuate the VCM;
detect a saturation in the analog command signal;
generate a first deglitch window during which the saturation detection is disabled; and
program the first deglitch window relative to the servo sample interval.

US Pat. No. 9,877,415

COLD STORAGE SERVER WITH HEAT DISSIPATION

WESTERN DIGITAL TECHNOLOG...

1. A cold storage server comprising:
a chassis;
a plurality of disk drives;
a nest positioned within the chassis and having a plurality of bays, each disk drive of the plurality of disk drives positioned
within one of the bays of the plurality of bays;

a single printed circuit board physically and electrically connected to all of the disk drives of the plurality of disk drives;
a retaining cover to secure the plurality of disk drives within the chassis;
a plurality of fasteners; and
a plurality of spacers, wherein:
each spacer of the plurality of spacers is positioned on one of the fasteners of the plurality of fasteners;
the spacers maintain a gap between a top of the single printed circuit board and a bottom of the retaining cover to dissipate
heat; and

each spacer is in contact with a disk drive of the plurality of disk drives and the retainer cover and configured to transfer
heat from the disk drive to the retainer cover.

US Pat. No. 9,529,710

INTERLEAVED CHANNELS IN A SOLID-STATE DRIVE

Western Digital Technolog...

1. A solid state drive (SSD), comprising:
non-volatile semiconductor memory (NVSM) comprising a plurality of solid state memory devices;
an SSD controller comprising a plurality of flash controllers; and
a plurality of channels, wherein a number of the plurality of channels is greater than a number of the plurality of flash
controllers, wherein each of the plurality of channels is coupled to at least one of the plurality of solid state memory devices,
wherein each of the plurality of channels is assigned a unique channel number, and

wherein every pair of channels assigned to two consecutive channel numbers are assigned to a different one of the plurality
of flash controllers to interleave the channels, and

wherein the SSD controller is configured to:
accumulate logical segments of data up to a size of a physical segment of data, and
sequentially program consecutive physical segments of data to channels assigned to two consecutive channel numbers to distribute
a programming load over the plurality of flash controllers.

US Pat. No. 9,275,697

UTILIZING DESTRUCTIVE FEATURES AS RAM CODE FOR A STORAGE DEVICE

Western Digital Technolog...

1. A host computing device comprising:
a controller configured to be connected to a data storage device separate from the host computing device and to:
maintain random access memory (RAM) code on the host device, the RAM code including instructions for performing a destructive
function on the data storage device;

temporarily load the RAM code onto a volatile memory of the data storage device during a manufacturing process, wherein the
loaded RAM code, when executed by one or more processors of the data storage device, directs the one or more processors to
perform the destructive function by completely erasing a non-volatile memory of the data storage device containing firmware
for operation of the data storage device; and

remove the loaded RAM code from the volatile memory of the data storage device, wherein the destructive function is unable
to be performed by the data storage device when the loaded RAM code is removed from the volatile memory.

US Pat. No. 9,489,296

METHODS, DEVICES AND SYSTEMS FOR HARDWARE-BASED GARBAGE COLLECTION IN SOLID STATE DRIVES

Western Digital Technolog...

1. A solid state drive controller, comprising:
a processor configured to couple to a plurality of non-volatile memory devices, each configured to store a plurality of physical
pages; and

a first volatile memory configured to store a logical-to-physical address translation map configured to enable the controller
to determine a physical location of logical pages stored within one or more of the plurality of physical pages;

wherein the processor is further configured to:
maintain, in the plurality of non-volatile memory devices, a plurality of journals defining physical-to-logical page correspondences
and comprising a plurality of journal entries, each entry associating one or more physical pages to a logical page, at least
one of the plurality of journals containing last-in-time updates to logical pages and stale entries that no longer point to
valid logical pages,

wherein each of the plurality of journals covers a predetermined physical region of the non-volatile memory, the predetermined
physical region comprising a predetermined range of the plurality of physical pages, and each of the plurality of journals
comprises an identification number based on address information of a physical page covered by the journal;

create a journal entry directly into one of the plurality of journals each time a logical page in the logical-to-physical
address translation map is updated; and

perform garbage collection, wherein garbage collection comprises:
reading entries of at least one of the plurality of journals;
determining a validity of each logical page referenced by the read entries through a comparison with a corresponding entry
in the address translation map, wherein the logical pages referenced by the read entries are stored in first physical pages;

writing logical pages determined to be valid to second physical pages and updating the address translation map accordingly;
and

designating at least the first physical pages as free space.

US Pat. No. 9,594,520

ATOMIC WRITE COMMAND SUPPORT IN A SOLID STATE DRIVE

Western Digital Technolog...

1. A method of performing an atomic write command in a data storage device comprising a volatile memory and a plurality of
non-volatile memory devices that are configured to store a plurality of physical pages, the method comprising:
storing data in a plurality of logical pages (L-Pages), each of the plurality of L-Pages being associated with a logical address;
maintaining a logical-to-physical address translation map in the volatile memory, the translation map being configured to
enable determination of a physical location, within one or more of the physical pages, of the data referenced by each logical
address;

receiving the atomic write command;
storing data specified by the atomic write command in at least one L-Page;
storing information tracking a range of L-Pages in which the writing of at least some L-Pages specified by the atomic write
command have been completed, wherein the written L-pages can be written out of order;

in the event the atomic write command does not complete, at reconstruction:
using the stored tracking information to generate a copy command that copies a current version of L-Pages within the range
that existed before the atomic write command; and

deferring an update to at least one entry in the translation map associated with the at least one L-Page storing the data
specified by the atomic write command until all L-Pages storing data specified by the atomic write command have been written
in a power-safe manner.

US Pat. No. 9,257,145

DISK DRIVE MEASURING DOWN-TRACK SPACING OF READ SENSORS

Western Digital Technolog...

1. A disk drive comprising:
a disk comprising a track, wherein the track comprises a sync mark;
a head comprising a plurality of read sensors including a first read sensor, and a second read sensor separated from the first
read sensor by a down-track spacing; and

control circuitry configured to:
generate a first time-stamp (TS1) after detecting the sync mark using the first read sensor as the disk rotates;

generate a second time-stamp (TS2) after detecting the sync mark using the second read sensor as the disk rotates; and

generate a calibration value representing the down-track spacing based on the TS1 and the TS2.

US Pat. No. 9,861,011

STACKABLE SLEDS FOR STORING ELECTRONIC DEVICES

HGST NETHERLANDS B.V., A...

1. A system, comprising:
sleds, each comprising:
sidewalls defining an interior space having a first open end;
a mounting plate, comprising opposing first and second sides, non-movably fixed relative to the sidewalls and positioned within
the interior space; and

a first cover movable relative to the sidewalls between a closed position, at least partially covering the first open end,
and an open position, uncovering the first open end, wherein the first cover comprises at least one first opening; and

at least one data storage device removably fixed to the first side of each mounting plate of the sleds such that, for each
sled, a first air gap is defined between the at least one data storage device and the first side of the mounting plate, and
a second air gap is defined between the at least one data storage device and the at least one first opening of the first cover;

wherein the sleds are stacked together such that the first covers of adjacent sleds are directly adjacent each other, and
the at least one first opening of the first cover of one sled at least partially overlaps the at least one first opening of
an adjacent sled.

US Pat. No. 9,484,051

METHOD AND SYSTEM FOR REDUCING UNDESIRABLE REFLECTIONS IN A HAMR WRITE APPARATUS

WESTERN DIGITAL TECHNOLOG...

4. A heat assisted magnetic recording (HAMR) write apparatus coupled with a laser for providing energy, the HAMR write apparatus
comprising:
a pole for writing to a region of the media, the pole including a media-facing surface;
at least one coil for energizing the pole;
a waveguide optically coupled with the laser and including a core and cladding;
a near-field transducer (NFT), the waveguide for directing a portion of the energy toward the NFT, the NFT located in a transmission
direction from the core of the waveguide; and

at least one antireflective mechanism residing in at least one of a first position in the waveguide, a second position in
the NFT and a third position between the waveguide and the NFT, the at least one antireflective mechanism having a location
selected from the first position within the waveguide and the third position between the waveguide and the NFT, the at least
one antireflective mechanism including a material having a thickness along the transmission direction selected to reduce reflections
in a reflection direction opposite to the transmission direction;

wherein the energy has a wavelength at the location and wherein the thickness is one-fourth of the wavelength plus an integral
number of one-half wavelengths.

US Pat. No. 9,355,654

SPIN TORQUE OSCILLATOR FOR MICROWAVE ASSISTED MAGNETIC RECORDING WITH INCREASED DAMPING

Western Digital Technolog...

26. A spin torque oscillator for a microwave assisted magnetic recording (MAMR) write head, comprising:
a first spacer adjacent to a write pole tip;
a polarization layer;
a field generating layer, wherein the polarization layer is configured to generate a spin-polarized current that excites magnetic
oscillations in the field generating layer to generate a microwave field;

a damping layer exchanged coupled to the field generating layer, wherein the damping layer is configured to tune a frequency
of the spin torque oscillator to match a frequency requirement of a recording media; and

a second spacer located between the damping layer and a trailing shield,
wherein the first spacer and the second spacer are configured to depolarize a current passing through the spin torque oscillator.

US Pat. No. 9,081,700

HIGH PERFORMANCE READ-MODIFY-WRITE SYSTEM PROVIDING LINE-RATE MERGING OF DATAFRAME SEGMENTS IN HARDWARE

Western Digital Technolog...

13. An apparatus for merging data frames, the apparatus comprising:
one or more devices configured to receive a first data frame comprising a plurality of sectors and a second data frame comprising
a plurality of sectors; and

circuitry comprising a plurality of data paths comprising a plurality of multiplexers, the circuitry configured to:
generate, using the plurality of data paths, a merged output data frame by merging sectors of the second data frame with sectors
of the first data frame; and

perform an error check on at least one check-data frame that comprises sectors corresponding to those in the first data frame
or the second data frame,

wherein at least some of the sectors in the check-data frame are transmitted on a subset of the plurality of data paths that
transmits sectors of the merged output data frame,

wherein the error check verifies the merged output data frame.

US Pat. No. 9,563,397

DISK DRIVE USING NON-VOLATILE CACHE WHEN GARBAGE COLLECTING LOG STRUCTURED WRITES

WESTERN DIGITAL TECHNOLOG...

1. A disk drive comprising:
a disk comprising a plurality of tracks, each track comprising a plurality of data sectors;
a head actuated over the disk; and
control circuitry operable to:
define a first circular buffer comprising at least two of the tracks;
overwrite a logical block address (LBA) mapped to a first data sector corresponding to a tail of the first circular buffer
by writing data to a second data sector at a head of the first circular buffer and remapping the LBA to the second data sector,
thereby invalidating the first data sector;

read first write data from previously written valid data sectors corresponding to the tail of the first circular buffer;
store the first write data in a non-volatile cache; and
flush the first write data from the non-volatile cache to the disk.

US Pat. No. 9,157,817

HSA SWAGE METROLOGY CALIBRATION USING SOLID WEIGHT GAUGE AND TORQUE SENSOR

Western Digital Technolog...

1. An assembly, comprising:
a head stack assembly (HSA) swaging tester device, the HSA swaging tester device comprising:
a base;
a top tooling assembly connected to the base, the top tooling assembly comprising:
an actuator motor;
a load cell connected to the actuator motor; and
a force gauge connected to the load cell, the force gauge being configured to measure torque imparted by the actuator motor
on an HSA being manufactured during an HSA swaging procedure; and

a selected one of a plurality of reference torque assemblies;
wherein the force gauge of the HSA swaging tester device is configured to be calibrated according to a selected one of a plurality
of types of HSAs to undergo the swaging procedure by:

coupling the selected one of the plurality of reference torque assemblies to an axle connected to the actuator motor, the
selected reference torque assembly being configured to impart a known torque onto the axle; and

adjusting the force gauge according to the torque imparted upon the axle by the selected reference torque assembly.

US Pat. No. 9,117,463

DATA STORAGE DEVICE ERASING MULTIPLE ADJACENT DATA TRACKS TO RECOVER FROM INTER-TRACK INTERFERENCE

Western Digital Technolog...

1. A data storage device comprising:
a disk comprising a plurality of data tracks;
a head actuated over the disk; and
control circuitry configured to perform a retry operation for a target data track by:
positioning the head at a first radial location and first erasing at least part of a first data track adjacent the target
data track;

after the first erasing, first reading the target data track to first recover target data recorded in the target data track;
when the first recovery fails, positioning the head at a second radial location and second erasing more of the first data
track; and

after the second erasing, second reading the target data track to second recover the target data recorded in the target data
track,

wherein:
the first erasing erases at least part of a second data track adjacent the first data track; and
the first erasing erases more of the second data track than the first data track.

US Pat. No. 9,245,556

DISK DRIVE EMPLOYING MULTIPLE READ ELEMENTS TO INCREASE RADIAL BAND FOR TWO-DIMENSIONAL MAGNETIC RECORDING

Western Digital Technolog...

1. A disk drive comprising:
a disk comprising a plurality of tracks;
a head comprising at least three read elements including a first read element, a second read element, and a third read element;
and

control circuitry configured to:
when the head is within a first radial band of the disk, detect data recorded on the disk using the first read element and
the second read element; and

when the head is within a second radial band of the disk different from the first radial band, detect data recorded on the
disk using the first read element and the third read element,

wherein when the head is over approximately a middle diameter of the disk, the first read element is substantially aligned
down-track with the third read element and the second read element is offset radially from the first read element and the
third read element by at least half a width of the second read element.

US Pat. No. 9,196,301

SUSPENSION CLAMP FOR CLAMPING A DISK DRIVE SUSPENSION TO AN ACTUATOR ARM

Western Digital Technolog...

1. A suspension clamp for clamping a disk drive suspension to an actuator arm, the suspension clamp comprising:
a housing including a spring operable to bias a latching member, wherein the latching member is rotatable about a pivot;
wherein:
after first compressing the spring and rotating the latching member in a first direction, the latching member is operable
to clamp the suspension to the actuator arm by decompressing the spring; and

after second compressing the spring and rotating the latching member in a second direction opposite the first direction, the
latching member is operable to unclamp the suspension.

US Pat. No. 9,189,264

NOTIFICATION PROPAGATION IN VIRTUAL COMPUTING ENVIRONMENT

Western Digital Technolog...

1. A computing device comprising:
a display;
a processor; and
a computer-readable medium having stored thereon instructions that, when executed by the processor, cause the processor to:
execute a user application in a first virtual computing environment while the first virtual computing environment is in a
background state, wherein the first virtual computing environment does not have control over the display while in the background
state;

intercept notification information associated with a first notification event associated with the user application;
using the first virtual computing environment, automatically convert the notification information to a format native to a
second virtual computing environment of a different type than the first virtual computing environment;

store the notification information in a network processing queue;
provide the notification information to the second virtual computing environment using a network protocol; and
receive, using the first virtual computing environment, additional notification information from the second virtual computing
environment, the additional notification information being associated with a second notification event that has occurred in
the second virtual computing environment.

US Pat. No. 9,153,262

DISK DRIVE ACTUATOR HAVING A RADIALLY STEPPED PIVOT BORE

Western Digital Technolog...

1. A disk drive, comprising:
a disk drive base;
a cover attached to the disk drive base to define a disk drive enclosure;
a disk rotatably attached to the disk drive base and disposed within the disk drive enclosure;
a head stack assembly (HSA) disposed within the disk drive enclosure, the HSA including:
an actuator body having a cylindrical bore therethrough and an actuator arm extending therefrom;
a head attached to a distal end of the actuator arm;
a pivot bearing cartridge disposed within the cylindrical bore and having a first end that is attached to the disk drive base;
and

a tolerance band radially preloaded between an outer surface of the pivot bearing cartridge and an inner surface of the cylindrical
bore;

wherein the cylindrical bore has a first diameter in a first region adjacent the disk drive base, and a second diameter in
a second region adjacent the cover, and a radial step between the first and second regions, the first diameter being different
from the second diameter by a diameter difference that is in the range of 20 microns to 100 microns.

US Pat. No. 9,141,176

POWER MANAGEMENT FOR DATA STORAGE DEVICE

Western Digital Technolog...

1. A data storage device (DSD) in communication with a host,
the DSD comprising:
at least one disk for storing data;
a solid state memory for storing data; and
a controller configured to:
count a number of commands received by the DSD from the host within a predetermined time period;
determine whether the number of commands received within the predetermined time period exceeds a threshold number of commands;
store data on the at least one disk and in the solid state memory based on whether the number of commands within the predetermined
time period exceeds the threshold number of commands; and

if the number of commands within the predetermined time period exceeds the threshold number of commands, increase an amount
of time until the at least one disk enters a low power state.

US Pat. No. 9,099,103

HEAT ASSISTED MAGNETIC RECORDING WITHINTERLACED HIGH-POWER HEATED AND LOW-POWER HEATED TRACKS

Western Digital Technolog...

1. A data storage system comprising:
a recording media including recording tracks;
a head situated to write to the media; and
a radiation source situated to heat a first track with a first power, a second track with a second power, and a third track
with a third power, wherein the second track is situated between the first track and the third track, and wherein the first
power and the third power are greater than the second power.

US Pat. No. 9,472,218

SUSPENSION ASSEMBLY HAVING A MICROACTUATOR ELECTRICALLY CONNECTED TO A GOLD COATING ON A STAINLESS STEEL SURFACE

Western Digital Technolog...

1. A suspension assembly comprising:
a suspension assembly mounting plate;
a microactuator mounting structure extending from the suspension assembly mounting plate;
a load beam extending from the microactuator mounting structure; and
a laminated flexure attached to the load beam, the laminated flexure including a tongue that has a read head bonding surface;
wherein the suspension assembly includes a stainless steel surface having a gold coating, and further comprises a microactuator
attached to the microactuator mounting structure and electrically connected to the gold coating,

wherein the load beam includes at least one hinge plate and the stainless steel surface is a stainless steel surface of the
hinge plate.

US Pat. No. 9,384,774

DATA STORAGE DEVICE CALIBRATING A LASER POWER FOR HEAT ASSISTED MAGNETIC RECORDING BASED ON SLOPE OF QUALITY METRIC

Western Digital Technolog...

5. A data storage device comprising:
a disk;
a head actuated over the disk, the head comprising a laser configured to heat the disk while writing data to the disk; and
control circuitry configured to:
(a) adjust a laser power for the laser;
(b) write a first pattern to a target track at the adjusted laser power;
(c) read the first pattern from the target track to generate a first read signal;
(d) generate a first quality metric based on the first read signal;
(e) write a second pattern to the target track at the adjusted laser power;
(f) read the second pattern from the target track to generate a second read signal;
(g) generate a second quality metric based on the second read signal;
(h) generate a third quality metric based on the first quality metric and the second quality metric;
(i) repeat blocks (a) through (h) at least once; and
(j) configure a write power for the laser based on a slope of the third quality metric.

US Pat. No. 9,355,666

DISK DRIVE MEASURING STROKE DIFFERENCE BETWEEN HEADS BY DETECTING A DIFFERENCE BETWEEN RAMP CONTACT

Western Digital Technolog...

14. A method of operating a data storage device, the method comprising:
moving first and second heads over respective disk surfaces to generate a contact signal; and
measuring a stroke difference between the first and second heads by detecting when the heads contact a ramp based on the contact
signal.

US Pat. No. 9,355,667

DATA STORAGE DEVICE SAVING ABSOLUTE POSITION AT EACH SERVO WEDGE FOR PREVIOUS WRITE OPERATIONS

Western Digital Technolog...

1. A data storage device comprising:
a disk comprising a plurality of tracks defined by servo sectors, wherein each servo sector comprises a plurality of servo
bursts and the servo sectors define a plurality of servo wedges;

a head actuated over the disk; and
control circuitry configured to:
execute a first write operation to a first track and generate a first absolute position for the head corresponding to a first
servo wedge;

execute a second write operation to a second track and generate a second absolute position for the head corresponding to the
first servo wedge; and

detect an off-track write condition when executing the second write operation based on the first absolute position and the
second absolute position;

wherein the first absolute position comprises a track address of the first track and a position error measurement based on
the servo bursts in the first servo wedge.

US Pat. No. 9,257,143

PRECAUTIONARY MEASURES FOR DATA STORAGE DEVICE ENVIRONMENTAL CONDITIONS

Western Digital Technolog...

1. A host in communication with at least one Data Storage Device (DSD), the host comprising:
an interface for communicating with the at least one DSD; and
a processor configured to:
send a request to the at least one DSD via the interface in preparation for sending a write command to the at least one DSD
to store data in the at least one DSD, wherein the request is for environmental information indicating an environmental condition
of the at least one DSD that is based on a number of times the at least one DSD has exceeded a write unsafe threshold within
a predetermined period of time or an amount of time since the at least one DSD has exceeded the write unsafe threshold, and
wherein the write unsafe threshold is a predetermined distance from a center of a track on a disk of the at least one DSD;

receive the environmental information from the at least one DSD via the interface;
determine whether the environmental information is within a threshold;
send the write command to the at least one DSD via the interface if the environmental information is within the threshold;
and

perform a precautionary measure if the environmental information is not within the threshold.

US Pat. No. 9,171,567

DATA STORAGE DEVICE EMPLOYING SLIDING MODE CONTROL OF SPINDLE MOTOR

Western Digital Technolog...

1. A data storage device comprising:
a head actuated over a disk;
a spindle motor configured to rotate the disk; and
control circuitry configured to:
sample a speed of the spindle motor;
generate an error signal based on a difference between the sampled speed and a target speed; and
generate a sliding mode control signal for controlling the speed of the spindle motor based on:
a first non-zero gain when the error signal is greater than zero and less than a first positive threshold; and
a second non-zero gain when the error signal is greater than the first positive threshold,
wherein a first slope of the sliding mode control signal defined by the first non-zero gain is contiguous with a second slope
of the sliding mode control signal defined by the second non-zero gain.

US Pat. No. 9,164,694

DATA STORAGE DEVICE DETECTING READ-BEFORE-WRITE CONDITIONS AND RETURNING CONFIGURABLE RETURN DATA

Western Digital Technolog...

1. A data storage device comprising:
data storage media comprising a plurality of data sectors; and
control circuitry programmed to:
receive a command from a host to cryptographically erase at least a portion of data stored on the data storage media;
execute a cryptographic erase;
receive a read command from the host to read a data sector in the data storage media, wherein the read command comprises a
logical block address (LBA);

map the LBA to a physical block address (PBA) representing the data sector;
use the PBA to read the data sector from the storage media to generate read data;
decrypt the read data to generate decrypted read data;
execute a data path protection check on the decrypted read data using at least one of the LBA and the PBA;
when the data path protection check fails, determine that the data sector has been cryptographically erased; and
return configurable return data to the host in response to determining that the data sector has been cryptographically erased.

US Pat. No. 9,093,102

SYSTEMS AND METHODS FOR TUNING SEED LAYER HARDNESS IN COMPONENTS OF MAGNETIC RECORDING SYSTEMS

Western Digital Technolog...

1. A method for tuning a seed layer hardness in components of a magnetic recording system, the method comprising:
providing a substrate comprising a component of a magnetic recording system;
depositing a seed layer material on a portion of a top surface of the substrate at a first angle; and
depositing a carbon material comprising sp3 carbon bonds on the portion of the top surface at a second angle not equal to
the first angle,

wherein the depositing the seed layer material and the depositing the carbon material on the top surface of the substrate
are performed simultaneously.

US Pat. No. 10,026,426

MAGNETIC TUNNEL JUNCTION (MTJ) FREE LAYER DAMPING REDUCTION

Western Digital Technolog...

1. A magnetic sensor comprising:a free layer;
a spin sink layer; and
a nonmagnetic spacer layer between the free layer and the spin sink layer.

US Pat. No. 9,454,212

WAKEUP DETECTOR

Western Digital Technolog...

1. A wakeup circuit for an electronic device, comprising:
a clock;
a sampling circuit, coupled to the clock, configured to:
synchronize a received input signal with the clock; and
generate an activity signal that includes an activity pulse for each state change in the synchronized input signal per cycle
of the clock; and

a qualification circuit, coupled to the sampling circuit, configured to:
open a qualification window upon detection of a first activity pulse in the activity signal;
in the event more than a threshold number of activity pulses in the activity signal are detected prior to closing the qualification
window, declare a wakeup event; and

close the qualification window.

US Pat. No. 9,195,530

SYSTEMS AND METHODS FOR IMPROVED DATA MANAGEMENT IN DATA STORAGE SYSTEMS

Western Digital Technolog...

1. A method for reducing data latency for a read-modify-write operation in a controller architecture comprising a controller
device and a bridge device coupled with non-volatile solid-state memory storage, the method comprising performing by the bridge
device:
in response to receiving, from the controller device, a first command comprising modification data and a first location of
parity data in the non-volatile memory storage and a second command instructing the bridge device to accumulate parity data
in connection with processing the first command:

reading data from the non-volatile memory storage, wherein reading the data comprises performing error correction in response
to detecting an error in the data;

modifying the read data with the modification data to generate modified data;
creating updated parity data based at least in part on the modification data and parity data stored at least partially in
the first location, wherein creating the updated parity data is performed by the bridge device without transferring the parity
data and the updated parity data to the controller device;

writing the modified data to the non-volatile memory storage; and
writing the updated parity data to the non-volatile memory storage without receiving an additional command from the controller
device, the additional command directing the bridge device to write the updated parity data,

whereby latency is reduced due to performance of the read-modify-write operation without transfer of the read data from the
bridge device to the controller device.

US Pat. No. 9,117,479

DATA STORAGE DEVICE CALIBRATING LASER WRITE POWER FOR HEAT ASSISTED MAGNETIC RECORDING

Western Digital Technolog...

10. A method of operating a data storage device, the method comprising:
applying a first write power to a laser of a head and writing a first test pattern to a disk;
reading the first test pattern while the head crosses over a width of the first test pattern to generate a first read signal;
generating a first track width metric based on the first read signal;
generating a first peak amplitude based on the first read signal;
applying a second write power to the laser and writing a second test pattern to the disk;
reading the second test pattern while the head crosses over a width of the second test pattern to generate a second read signal;
generating a second track width metric based on the second read signal;
generating a second peak amplitude based on the second read signal;
processing the first track width metric, the first peak amplitude, the second track width metric, and the second peak amplitude
to estimate a coefficient C of an error function (erf):

PeakAmplitude=Amax*erf(TrackWidthMetric/C)

where A max represents a maximum peak amplitude; and
calibrating an operating write power for the laser based on the estimated coefficient C of the error function.

US Pat. No. 9,053,726

DATA STORAGE DEVICE ON-LINE ADAPTING DISTURBANCE OBSERVER FILTER

Western Digital Technolog...

1. A data storage device comprising:
a disk comprising tracks defined by servo sectors;
a head; and
control circuitry configured to:
measure a location of the head over the disk based on the servo sectors;
generate a position error signal (PES) representing a difference between a target location for the head and the measured location
for the head;

generate an actuator control signal (ACS) in response to the PES;
generate a disturbance compensation signal (DCS) based on the PES and the ACS;
filter the DCS with a disturbance observer filter;
adjust the ACS based on an output of the disturbance observer filter;
actuate the head over the disk based on the adjusted ACS;
filter the DCS with a plurality of band-pass filters different from the disturbance observer filter; and
adjust the disturbance observer filter based on the plurality of band-pass filters.

US Pat. No. 9,171,003

SHARED MEDIA CRAWLER DATABASE METHOD AND SYSTEM

Western Digital Technolog...

1. A method of monitoring files stored in a volume comprising at least one storage device, comprising:
monitoring, by a crawler, the at least one storage device;
maintaining, by the crawler, a catalog for files stored within the volume;
receiving, by the crawler, an event indicating a change to a file stored on the at least one storage device;
transcoding, by the crawler, the file from a first format to a second format;
extracting, by the crawler, metadata for the file;
storing, by the crawler in the volume, information indicating the change and the transcoding in the catalog of the files;
determining a set of subscribers that have requested to receive a notification of the event;
retrieving notification criteria for the set of subscribers from the catalog of files;
evaluating the retrieved notification criteria for each of the set of subscribers; and
sending a notification of the event to those subscribers whose notification criteria are satisfied.

US Pat. No. 9,064,537

DISK DRIVE MEASURING RADIAL OFFSET BETWEEN HEADS BY DETECTING A DIFFERENCE BETWEEN RAMP CONTACT

Western Digital Technolog...

1. A disk drive comprising:
a plurality of disk surfaces including a first disk surface and a second disk surface;
a first head actuated over the first disk surface;
a second head actuated over the second disk surface;
a ramp proximate an outer diameter of the disk surfaces; and
control circuitry configured to:
measure a first time interval while moving the first head toward the ramp until the first head contacts the ramp;
measure a second time interval while moving the second head toward the ramp until the second head contacts the ramp; and
measure a radial offset between the first head and the second head based on the first interval and the second interval.

US Pat. No. 9,059,742

SYSTEM AND METHOD FOR DYNAMIC SCALING OF LDPC DECODER IN A SOLID STATE DRIVE

Western Digital Technolog...

1. A data storage device, including:
a memory; and
a controller comprising:
an encoder configured to encode data to be written to the memory; and
a decoder configured to decode data read from the memory, the decoder comprising:
an iterative unit configured to iterate using a plurality of messages;
a trigger unit configured to detect one or more trigger conditions based at least in part on one or more internal states of
the decoder; and

a scaling unit to scale messages output by the iterative unit when the trigger unit detects the occurrence of the one or more
trigger conditions, the scaled messages being used as input to the iterative unit for a next iteration.

US Pat. No. 9,472,219

DATA STORAGE DEVICE CALIBRATING PARAMETER FOR HEAT ASSISTED MAGNETIC RECORDING

Western Digital Technolog...

1. A data storage device comprising:
a disk;
a head actuated over the disk, wherein the head comprises a laser configured to heat the disk while writing data to the disk;
and

control circuitry configured to:
(a) calibrate a write power for the laser, wherein the write power is applied to the laser while writing user data to the
disk;

(b) apply a calibration power to the laser for a first interval, wherein the calibration power is high enough to cause the
head to contact the disk if applied for a second interval longer than the first interval;

(c) while applying the calibration power to the laser, write test data to the disk during at least part of the first interval;
and

(d) read the test data from the disk to generate a read signal and generate a metric based on the read signal.

US Pat. No. 9,360,900

CAPTIVATING SHOCK MOUNTS FOR DATA STORAGE DEVICES USING RETENTION CLIPS

Western Digital Technolog...

1. A data storage assembly comprising:
an enclosure comprising a first set of one or more pockets for receiving a first set of one or more shock mounts configured
to be coupled to a data storage device;

a cover configured to enclose the enclosure; and
a set of one or more retention clips separate from the cover and configured to latch with the first set of one or more pockets
to retain the first set of one or more shock mounts.

US Pat. No. 9,299,371

DISK DRIVE SLIDER WITH SENSE AMPLIFIER FOR COUPLING TO A PREAMP THROUGH A SUPPLY/BIAS LINE AND A READ SIGNAL LINE

Western Digital Technolog...

1. A disk drive comprising:
a disk;
a slider actuated over the disk, the slider comprising a first read element and a second read element; and
control circuitry configured to:
calibrate a first bias supplied to the first read element;
calibrate a second bias supplied to the second read element;
generate an operating bias based on the first bias and the second bias; and
apply the operating bias to the first read element and the second read element when reading data from the disk.

US Pat. No. 9,274,966

DYNAMICALLY THROTTLING HOST COMMANDS TO DISK DRIVES

Western Digital Technolog...

10. A method, comprising:
receiving information comprising at least one of:
a rate at which data is being drained from a cache memory in a disk drive to a rotating media in a disk drive; and
at least one environmental condition of the disk drive;
determining a throttling decision from the received information; and
throttling a rate of host commands sent from a host and received by the disk drive based on the throttling decision by introducing
a delay between each of the host commands based on the information and a minimum throughput requirement of the cache memory,
the delay being increased in response to a decline in the rate at which data is being drained from the cache memory while
the rate at which data is being drained from the cache memory is at or above the minimum throughput requirement, and the delay
being decreased for the rate at which data is being drained from the cache memory falling below the minimum throughput requirement
of the cache memory.

US Pat. No. 9,277,670

RISER CARD FOR RACK-MOUNTED NETWORK ATTACHED STORAGE

Western Digital Technolog...

1. A rack-mounted network attached storage device comprising:
an enclosure configured as a rack-mounted enclosure;
a motherboard comprising at least one expansion slot;
a riser card, coupled to the at least one expansion slot, comprising:
a first power interface configured to receive power from an external DC power supply,
a second power interface from an internal DC power supply configured to receive power from the motherboard via the expansion
slot,

a plurality of drive interface connectors; and
a first sharing circuit configured to share power received via the first and second power interfaces, and
a plurality of drives coupled to the riser card.

US Pat. No. 9,171,583

DISK DRIVE HAVING A TOP COVER CHANNEL VENTED TO A CENTRAL CAVITY VIA A PERIPHERAL CLEARANCE GAP

Western Digital Technolog...

1. A disk drive comprising:
a disk drive base comprising a central cavity surrounded by a peripheral wall, the peripheral wall including a peripheral
top face; and

a top cover attached to the disk drive base and disposed over the central cavity to define a disk drive enclosure, the top
cover having a central top face that defines a central top face plane, an outer periphery of the top cover being spaced from
the peripheral wall of the disk drive base by a peripheral clearance gap;

a disk rotatably attached to the disk drive base within the central cavity and disposed within the disk drive enclosure; and
a foil seal adhered to the central top face and the peripheral top face, and spanning the peripheral clearance gap;
wherein the central top face of the top cover includes a first channel that is depressed towards the disk relative to the
central top face plane,

wherein the foil seal covers the first channel,
and wherein the first channel is vented to the central cavity by a venting channel that connects the first channel to the
peripheral clearance gap.

US Pat. No. 9,165,668

DATA RETENTION MONITORING USING TEMPERATURE HISTORY IN SOLID STATE DRIVES

Western Digital Technolog...

1. A solid-state storage device comprising:
a non-volatile solid-state memory array comprising a plurality of non-volatile memory devices configured to store data;
a temperature sensor; and
a controller configured to:
write user data to the non-volatile solid-state memory array at a first time;
receive a signal from the temperature sensor indicating a temperature of at least a portion of the non-volatile memory array
at a second time;

determine a data retention acceleration factor value based at least in part on the temperature signal;
determine an accumulated effective data retention time period relative to a reference temperature based at least in part on
the data retention acceleration factor value;

determine whether the effective data retention time period exceeds a predetermined threshold value; and
cause a data refreshing operation to be executed when it is determined that the predetermined threshold value was exceeded.

US Pat. No. 9,128,639

SCHEDULING COMMANDS IN A DEPENDENT ARRAY OF DISK DRIVES

Western Digital Technolog...

1. A controller in an array of disk drives, the controller comprising:
control circuitry configured to:
transmit a first access command out of a group of access commands to a first disk drive in the array;
transmit a plurality of access commands out of the group of access commands to a plurality of disk drives in the array other
than the first disk drive; and

transmit a completion status to the first disk drive, wherein the completion status identifies a status of the plurality of
access commands transmitted to the other disk drives.

US Pat. No. 9,122,405

FAST INITIALIZATION OF STORAGE DEVICE

Western Digital Technolog...

1. A method of creating a redundant array of independent disks (RAID) in a storage device, said method comprising:
creating, for a first time, a RAID array on factory fresh drives installed in the storage device;
connecting the storage device to an uninterruptable power supply; and
rebuilding the RAID array in the storage device based on initiating a forced rebuild of the RAID array.

US Pat. No. 9,075,714

ELECTRONIC SYSTEM WITH DATA MANAGEMENT MECHANISM AND METHOD OF OPERATION THEREOF

Western Digital Technolog...

1. An apparatus comprising:
a media;
a head over the media;
a read channel, coupled to the head, configured to extract data from the media;
control circuitry, coupled to the read channel, configured to execute a read command; and
wherein the read channel is further configured to:
generate, based on extracting the data from the media, a data condition indicator including a locality error indicator, and
provide, for use by the control circuitry, the data and the data condition indicator.

US Pat. No. 9,070,379

DATA MIGRATION FOR DATA STORAGE DEVICE

Western Digital Technolog...

1. A data storage device (DSD), comprising:
a disk for storing data;
a spindle motor for rotating the disk;
a solid state memory for storing data; and
a controller configured to:
control the spindle motor to rotate the disk to perform at least one operation on the disk;
determine a number of commands queued for performing the at least one operation;
determine whether the number of commands queued is greater than a target level of commands; and
if it is determined that the number of commands queued is not greater than the target level, transfer data between the solid
state memory and the disk to increase the number of commands queued to reach the target level while the disk rotates.

US Pat. No. 9,063,838

DATA STORAGE DEVICE SHIFTING DATA CHUNKS OF ALIGNMENT ZONE RELATIVE TO SECTOR BOUNDARIES

Western Digital Technolog...

1. A data storage device comprising a non-volatile memory comprising a plurality of sectors, and control circuitry operable
to define at least one alignment zone comprising a plurality of chunks including a plurality of data chunks and a plurality
of pad chunks, wherein:
each chunk comprises a plurality of sectors;
each sector is operable to store X host blocks, where X is an integer greater than one;
the alignment zone comprises at least X?1 pad chunks; and
the control circuitry is operable to:
shift the data chunks of the alignment zone by a non-zero integer number of chunks equal to or less than X?1 plus a corresponding
offset;

first shift the data chunks right by N1 chunks plus a first offset while maintaining at least one copy of the data chunks;
after first shifting the data chunks right by N1 chunks, second shift the data chunks left by N2 chunks plus a second offset
while maintaining at least one copy of the data chunks; and

after second shifting the data chunks left by N2 chunks, third shift the data chunks left by N3 chunks plus a third offset
while maintaining at least one copy of the data chunks,

wherein the first, second, and third offsets represent different fractions of a sector.

US Pat. No. 10,021,777

TEMPERATURE-BASED DATA REFRESHING

Western Digital Technolog...

1. A data storage device comprising:non-volatile media; and
a controller configured to:
write host data associated with a write command to the non-volatile media while a temperature of the at least a portion of the data storage device is at a first level below a predetermined threshold;
store write indication data, the write indication data indicating that the host data was written to the non-volatile media while the temperature of the at least a portion of the data storage device was below the predetermined threshold;
determine that the temperature of the at least a portion of the data storage device has risen to a second level that is above the predetermined threshold; and
based at least in part on the determination that the temperature of the at least a portion of the data storage device has risen to the second level, re-write the previously-written host data in the non-volatile media.

US Pat. No. 9,436,480

FIRMWARE RAM USAGE WITHOUT OVERLAYS

Western Digital Technolog...

1. A computing device comprising:
a volatile random access memory (RAM);
a non-volatile boot read-only memory (ROM) comprising ROM boot loader code;
a non-volatile flash memory storing program code comprising:
initialization code designed to be executed a single time during device booting;
main program code separate from the initialization code and designed to be executed after execution of the initialization
code; and

main code loader code designed to cause the main program code to be loaded from the flash memory to the RAM; and
a controller configured to:
read the ROM boot loader code from the boot ROM and execute the ROM boot loader code;
in response to said executing the ROM boot loader code, load the initialization code and the main code loader code to first
and second adjacent portions of the RAM, respectively, as part of a single load operation;

execute the initialization code;
execute the main code loader code;
in response to said executing the main code loader code, load the main program code, separately from the initialization code,
to a third portion of the RAM at least partially overlapping the first portion but not overlapping the second portion, thereby
at least partially overwriting the initialization code; and

execute the main program code.

US Pat. No. 9,361,938

DISK DEFECT MANAGEMENT FOR A DATA STORAGE DEVICE

Western Digital Technolog...

1. A Data Storage Device (DSD), comprising:
at least one disk surface for storing data;
a memory for storing a bitmap buffer; and
a controller configured to:
identify a plurality of segments on the at least one disk surface with each segment including at least one defect region;
generate a segment bitmap for each of the plurality of segments indicating the at least one defect region within the segment;
store the generated segment bitmaps for the plurality of segments in the bitmap buffer; and
create a linked list with a plurality of entries corresponding to the plurality of segments, wherein each entry of the plurality
of entries includes location information for a segment of the plurality of segments indicating a location of the segment on
the at least one disk surface and an address for accessing a segment bitmap for the segment in the bitmap buffer.

US Pat. No. 9,315,008

METHOD AND APPARATUS FOR ALIGNING AN ILLUMINATION UNIT TO A SLIDER FOR A MAGNETIC RECORDING DEVICE

Western Digital Technolog...

1. An alignment method for bonding a first component to a second component comprising:
providing a plurality of sliders, each slider having alignment markers on a first portion of a top surface, and a waveguide
adjacent to the alignment markers, wherein each slider comprises the first component;

providing a plurality of illumination units with alignment markers, wherein each illumination unit comprises the second component;
substantially aligning the alignment markers of the first component to the alignment markers of the second component to establish
an initial alignment position;

irradiating a light source onto the slider while evaluating light emitted from the waveguide on a bottom surface of the first
component, and incrementally moving the first component with respect to the second component from the initial alignment position
until light emitted from the waveguide at the bottom surface of the first component indicates a position of optical alignment
has been located;

calculating an offset from the initial alignment position of the slider to the optical alignment position; and
bonding a plurality of first components to a plurality of second components by placing each one of the first components in
the initial alignment position relative to a corresponding one of the second components, and then adjusting the position of
each one of the first components by the calculated offset prior to bonding the first and second components together.

US Pat. No. 9,308,609

DE-SWAGE MACHINE FOR REMOVAL OF A HEAD FROM A HEAD STACK ASSEMBLY AND METHOD OF USING THE SAME

Western Digital Technolog...

1. A de-swage machine for removal of a head of a head stack assembly comprising:
a tooling unit comprising a first actuator motor and configured to receive a head stack assembly comprising a selected head
for removal;

a blade module comprising a blade and a second actuator motor;
an imaging unit configured to generate position information of the blade and position information of the selected head; and
a controller configured to perform auto gage verification and remove the selected head by at least:
receiving an assigned position information of the blade, and an assigned position information of the selected head from a
database;

determining whether the position information of the blade matches the assigned position information of the blade;
indicating that there is a de-swage machine error when the position information of the blade does not match the assigned position
information of the blade;

determining whether the position information of the selected head matches the assigned position information of the selected
head;

indicating that there is a de-swage machine error when the position information of the selected head does not match the assigned
position information of the selected head;

aligning the selected head with the blade using the first actuator motor and the second actuator motor; and
moving the blade towards the head stack assembly to remove the selected head from the head stack assembly.

US Pat. No. 9,245,577

DATA STORAGE DEVICE COMPRISING SPINDLE MOTOR CURRENT SENSING WITH SUPPLY VOLTAGE NOISE ATTENUATION

Western Digital Technolog...

1. A data storage device comprising:
a disk;
a spindle motor configured to rotate the disk, wherein the spindle motor comprises a plurality of windings;
a head actuated over the disk; and
control circuitry configured to:
power the spindle motor with a power voltage generated in response to a supply voltage;
enable a clamping circuit when sensing a current flowing from the power voltage through at least one of the windings, wherein
the clamping circuit is configured to clamp the power voltage to less than a peak voltage of the supply voltage in order to
attenuate noise in the power voltage; and

disable the clamping circuit when not sensing the current.

US Pat. No. 9,106,592

CONTROLLER AND METHOD FOR CONTROLLING A BUFFERED DATA TRANSFER DEVICE

Western Digital Technolog...

1. A method for controlling a buffered data transfer between a source and a destination, the method comprising:
loading a source count value from a buffered data transfer device;
loading a destination count value from the buffered data transfer device;
computing a source delta value by subtracting a source previous value from the source count value;
adjusting the destination count value on the buffered data transfer device by adding the source delta value to the destination
count value;

computing a destination delta value by subtracting a destination previous value from the destination count value;
adjusting the source count value on the buffered data transfer device by adding the destination delta value to the source
count value;

computing a new value for the source previous value by adding the source count value and the destination delta value; and
computing a new value for the destination previous value by adding the destination count value and the source delta value.

US Pat. No. 9,472,242

HARD DISK DRIVE ENCLOSURE BASE WITH FEED THROUGH FLEXURE DESIGN AND ACCOMPANYING FLEXURE

WESTERN DIGITAL TECHNOLOG...

1. A storage drive base having an interior side and an exterior side, the storage drive base comprising:
a slotted aperture passing through the storage drive base from the interior side to the exterior side;
a flexible circuit having a first end disposed on the interior side of the storage drive base and a second end disposed on
the exterior side of the storage drive base,

wherein the first end of the flexible circuit is installed through the slotted aperture and aligned so that the first end
lays flat along an interior surface of the storage drive base in a location proximal to the slotted aperture, and

wherein the first end of the flexible circuit includes at least one exposed interior electrode contact pad exposed to the
interior of the storage drive base; and

a sealing-adhesive barrier, applied between edges of the slotted aperture and the flexible circuit, to form a hermetic seal
between the exterior side and the interior side of the storage drive base.

US Pat. No. 9,099,144

DISK DRIVE EVALUATING LASER PERFORMANCE FOR HEAT ASSISTED MAGNETIC RECORDING

Western Digital Technolog...

1. A disk drive comprising:
a disk;
a head comprising a laser configured to heat the disk while writing to the disk; and
control circuitry configured to:
write data to the disk using an operating laser power applied to the laser;
read the data from the disk to generate a first read signal; and
measure a ramp interval for an amplitude of the first read signal to ramp up to a first threshold.

US Pat. No. 9,099,153

STORAGE DEVICE WITH A COVER SUPPORTING PORTION

Western Digital Technolog...

1. A disk drive assembly comprising:
a base;
a cover;
a post extending from the base toward the cover; and
a latch movably mounted on the post such that the post extends there through,
wherein the post comprises a cover supporting portion configured to:
support the cover, and
prevent the cover from compressing the latch and causing the latch to contact both the cover and the base simultaneously when
a load is applied to a portion of the cover above the latch and

wherein the post has a height sufficiently greater than the height of the latch to provide a clearance between the cover and
the base and prevent the latch from simultaneously contacting both the cover and the base when the external load is applied
to a portion of the cover and the cover contacts the cover supporting portion.

US Pat. No. 9,948,322

HIGH PERFORMANCE READ-MODIFY-WRITE SYSTEM PROVIDING LINE-RATE MERGING OF DATAFRAME SEGMENTS IN HARDWARE

WESTERN DIGITAL TECHNOLOG...

1. A circuit, comprising:a merge multiplexer;
first and second multiplexers, wherein the first multiplexer is configured to output sectors of a second data frame to the second multiplexer and the merge multiplexer;
third and fourth multiplexers, wherein the third multiplexer is configured to output sectors of a first data frame to the fourth multiplexer and the merge multiplexer; and
a logic device configured to:
input sectors of the first data frame and the second data frame that are output from the fourth multiplexer and the second multiplexer, respectively; and
perform an error check on a first check-data frame comprising the sectors corresponding to sectors in the first data frame and a second check-data frame comprising the sectors corresponding to sectors in the second data frame;
wherein the merge multiplexer is configured to merge one or more sectors from the first multiplexer with one or more sectors from the second multiplexer based on a merge mask to form a merged output data frame,
wherein at least some of the sectors in the first and second check-data frames are transmitted on a subset of a plurality of data paths different from a subset of the plurality of data paths that transmits sectors of the merged output data frame, and
wherein the error check verifies the merged output data frame.

US Pat. No. 9,299,384

ULTRA-THIN HDD EMBEDDED DISK CLAMP DESIGN

Western Digital Technolog...

1. A method of assembling a disk drive, the method comprising:
providing:
(1) a hub comprising a non-circular protrusion extending from a top surface thereof,
(2) a disk clamp comprising a non-circular opening, and a lower surface having an inner region formed proximate to the non-circular
opening, an outer region formed radially outward of the inner region, and a raised region formed between the inner region
and the outer region, and

(3) at least one disk;
inserting the hub through the disk;
inserting the non-circular protrusion extending from the top surface of the hub into the non-circular opening of the disk
clamp; and

fixing the disk clamp to the hub such that inner region contacts the hub, the outer region contacts the disk, and the raised
region forms an air gap between the hub and the clamp, wherein the outer region of the disk clamp provides a clamping force
to the disk.

US Pat. No. 9,196,275

MAGNETIC HEAD SEPARATOR FIN MATERIAL TO PREVENT PARTICULATE CONTAMINATION ON SLIDER

Western Digital Technolog...

1. An apparatus for a magnetic storage drive comprising a magnetic head assembly having a first slider and a second slider
arranged with a gap between the first and second sliders, the first slider comprising a first magnetic head and the second
slider comprising a second magnetic head, the apparatus comprising:
a ramp constructed of a first material, the ramp being configured to guide and hold the magnetic head assembly in place when
parked; and

a fin constructed of a second material different than the first material, the fin coupled to the ramp and arranged between
the first slider and the second slider to protect the first slider from contacting the second slider while maintaining a clearance
to each of the first slider and the second slider when the magnetic head assembly is parked on the ramp.

US Pat. No. 9,075,708

SYSTEM AND METHOD FOR IMPROVING DATA INTEGRITY AND POWER-ON PERFORMANCE IN STORAGE DEVICES

Western Digital Technolog...

1. A non-volatile storage system, comprising:
a non-volatile storage array; and
a controller comprising a volatile memory, the controller configured to:
maintain a mapping table and a record of invalid physical addresses in the volatile memory, wherein a data size of a logical
address referenced by an entry of the mapping table is larger than a data size of an atomic program command that can be executed
on the non-volatile storage array;

receive a write command from a host system directed to a logical address referenced by an entry in the mapping table;
identify a plurality of physical addresses to be used for the write command, wherein performing the write command comprises
executing a plurality of program commands, and wherein each of the program commands corresponds to a different physical address
from the plurality of physical addresses;

mark each physical address of the plurality of physical addresses as invalid in the record of invalid physical addresses;
save a copy of the record of invalid physical addresses to the non-volatile storage array;
after saving the copy of the record, execute the plurality of program commands on the non-volatile storage array at the plurality
of physical addresses; and

when the execution of the plurality of program commands is complete, mark each physical address of the plurality of physical
addresses as valid in the record of invalid physical addresses to obtain an updated record of invalid physical addresses that
reflects changes made by the execution of the program commands and replace the coy of the record with a copy of the updated
record at the non-volatile storage array,

whereby saving the copy of the record of invalid physical addresses before executing the plurality of program commands and
replacing the copy with the updated record of invalid physical addresses after execution of the plurality of program commands
is complete transforms the plurality of program commands into an atomic transaction.

US Pat. No. 9,074,941

SYSTEMS AND METHODS FOR MEASURING AMBIENT AND LASER TEMPERATURE IN HEAT ASSISTED MAGNETIC RECORDING

Western Digital Technolog...

1. A system for measuring temperature in a heat assisted magnetic recording, the system comprising:
a slider comprising a write head;
a laser diode coupled to the slider and configured to direct energy to a magnetic medium; and
a preamplifier circuit comprising:
a voltage measurement circuit configured to measure a voltage drop across the laser diode; and
a current measurement circuit configured to measure a current through the laser diode;
wherein the preamplifier circuit is configured to:
store calibration information comprising a plurality of temperatures corresponding with measurements of the voltage drop across
the laser diode and measurements of the current through the laser diode; and

calculate a temperature based on the measured voltage drop across the laser diode, the measured current through the laser
diode, and the calibration information.

US Pat. No. 9,355,676

DATA STORAGE DEVICE CONTROLLING AMPLITUDE AND PHASE OF DRIVING VOLTAGE TO GENERATE POWER FROM A SPINDLE MOTOR

Western Digital Technolog...

1. A data storage device comprising:
a disk;
a spindle motor configured to rotate the disk, wherein the spindle motor comprises a plurality of windings;
a head actuated over the disk; and
control circuitry powered by a supply voltage, the control circuitry configured to:
commutate the windings of the spindle motor based on a commutation sequence while applying a periodic driving voltage to each
winding, wherein the periodic driving voltage comprises an operating amplitude during normal operation; and

when the supply voltage falls below a threshold, configure the spindle motor into a power generator by at least adjusting
the amplitude and a phase of the periodic driving voltage so that a periodic current flowing through each winding is substantially
opposite in phase from a sinusoidal back electromotive force (BEMF) voltage generated by each winding,

wherein adjusting the amplitude and the phase of the periodic driving voltage comprises adjusting at least one of the amplitude
and the phase based on an amplitude of the sinusoidal BEMF voltage, a resistance of the windings, and an inductance of the
windings.

US Pat. No. 9,252,671

POWER SUPPLY WITH VOLTAGE OUTPUT RESPONSIVE TO LOAD DEMAND

Western Digital Technolog...

1. A power adapter, comprising:
a rectifier and filter configured to be coupled to an input alternating current (AC) source and to generate a direct current
(DC) transformer input signal;

a transformer, the transformer comprising a primary winding coupled to the transformer input signal and a secondary winding
coupled to an output of the power adapter;

a current sensor configured to enable determination of an output current drawn at the output of the power adapter and to generate
a current sense signal; and

a controller configured to a) regulate a voltage at the output of the power adapter by controlling current flowing through
the primary winding of the transformer and b) select an output voltage from at least a first voltage and a second voltage
based upon the current sense signal.

US Pat. No. 9,245,558

ELECTRONIC SYSTEM WITH DATA MANAGEMENT MECHANISM AND METHOD OF OPERATION THEREOF

Western Digital Technolog...

1. An apparatus comprising:
a media;
a head over the media;
a head actuation motor coupled to the head; and
control circuitry, coupled to the head actuation motor, configured to position the head; and
wherein the control circuitry is further configured to adjust a frequency of a background task based on a success ratio of
the background task.

US Pat. No. 9,230,605

DATA STORAGE DEVICE MAXIMIZING AREAL DENSITY BASED ON A TARGET QUALITY METRIC

Western Digital Technolog...

1. A data storage device comprising:
a disk;
a head actuated over the disk; and
control circuitry configured to:
write data to the disk and read the data from the disk to measure a quality metric;
repeatedly adjust a recording parameter and measure the quality metric for each adjustment of the recording parameter; and
select an operating value for the recording parameter that corresponds to a substantially maximum areal density for the disk
when the measured quality metric substantially matches a target quality metric.

US Pat. No. 9,214,186

DATA STORAGE DEVICE MEASURING RADIAL OFFSET BETWEEN READ ELEMENT AND WRITE ELEMENT

Western Digital Technolog...

1. A data storage device comprising:
a disk comprising a plurality of tracks;
a head actuated over the disk, the head comprising a read element radially offset from a write element; and
control circuitry configured to:
write a first pattern to a single track;
read the first pattern from the single track to generate a first read signal;
generate a first quality metric based on the first read signal;
write a second pattern to the single track, wherein the second pattern is different from the first pattern;
read the second pattern from the single track to generate a second read signal;
generate a second quality metric based on the second read signal; and
measure the radial offset of the read element and write element based on the first and second quality metrics.

US Pat. No. 9,196,292

ROTARY SPINDLE HAVING A DISK CLAMP BOTTOM LAND FACING AND IN CONTACT WITH A SHAFT TOP LAND

Western Digital Technolog...

1. A rotary spindle comprising:
a rotatable shaft defining a shaft axis of rotation, and having a shaft top land normal to the shaft axis of rotation;
a disk mounting hub having an outer disk mounting surface, and having an inner cylindrical surface that faces and is in press-fit
radial compression with an outer cylindrical surface of the shaft at a cylindrical hub-to-shaft interface, the cylindrical
hub-to-shaft interface being concentric about the shaft axis of rotation; and

a disk clamp fastened to the rotatable shaft, the disk clamp having a clamp bottom land that faces and is in contact with
the shaft top land, the disk clamp not having bottom contact with the disk mounting hub;

wherein the hub-to-shaft interface includes at least one circumferential groove that contains an adhesive sealing material.

US Pat. No. 9,153,266

DATA STORAGE DEVICE MEASURING LASER PROTRUSION FLY HEIGHT PROFILE

Western Digital Technolog...

1. A data storage device comprising:
a disk comprising a plurality of tracks, where each track comprises a plurality of servo sectors and at least one data segment
between consecutive servo sectors;

a head actuated over the disk, the head comprising a laser configured to heat the disk during write operations based on a
laser power; and

control circuitry configured during a first revolution of the disk to:
first increase the laser power over a first interval to cause at least part of the head to protrude toward a first data segment
of the disk; and

after the first interval, first decrease the laser power and read a fly height pattern from the first data segment to first
measure a fly height of the head.

US Pat. No. 9,153,287

DATA ACCESS FOR SHINGLED MAGNETIC RECORDING MEDIA

Western Digital Technolog...

1. A method for performing pre-read and/or post-read operations in a disk drive in communication with a host, wherein the
disk drive includes a data cache memory and at least one disk with a plurality of sectors for storing data, the method comprising:
receiving a read command from the host requesting user data from a first sector of the plurality of sectors;
reading user data and parity data from a second sector of the plurality of sectors during a pre-read or post-read operation
in performing the read command, wherein the second sector is adjacent the first sector on the at least one disk, and wherein
the parity data can be used for error correction of the user data read from the second sector;

recovering a logical block address (LBA) for the user data read from the second sector using the parity data, wherein the
LBA is not stored on the at least one disk with the user data; and

determining whether to store in the data cache memory the user data read from the second sector during the operation based
on the recovered LBA for the user data read from the second sector.

US Pat. No. 9,122,417

NETWORK ATTACHED STORAGE (NAS) PROTECTION METER AND METHODS FOR ALERTING USERS OF THE STATE OF PROTECTION OF A NAS

Western Digital Technolog...

1. A network attached storage (NAS), comprising:
at least one storage device;
a network connection coupling the at least one storage device to a network; and
a processor coupled to the at least one storage device and to the network connection, the processor being configured to:
adjust a granularity of protection levels for the at least one storage device based on user input, wherein different granularities
comprise a different number of protection levels and wherein different granularities are associated with different combinations
of operating parameters;

receive a selection from the user of a manner in which a current protection level of the protection levels of the at least
one storage device is to be provided and communicated to the user;

monitor a plurality of operating parameters of the network attached storage, at least one of the monitored parameters being
unrelated to data or to an amount of storage space remaining on the network attached storage;

determine a state of a network attached storage based on at least two of the monitored plurality of operating parameters of
the network attached storage, at least one of the two monitored plurality of operating parameters being unrelated to the amount
of storage space remaining on the network attached storage;

determine the current protection level based on the determined state of the network attached storage; and
provide to the user an indication of the determined protection level afforded by the network attached storage according to
the received selection.

US Pat. No. 9,099,147

DATA STORAGE DEVICE COMMUTATING A SPINDLE MOTOR USING CLOSED-LOOP ROTATION PHASE ALIGNMENT

Western Digital Technolog...

1. A data storage device comprising:
a disk;
a spindle motor configured to rotate the disk, wherein the spindle motor comprises a plurality of windings;
a head actuated over the disk; and
control circuitry comprising an oscillator configured to drive a commutation controller configured to commutate the windings
based on a commutation sequence, the control circuitry configured to:

measure a rotation phase of the spindle motor;
generate a phase error based on the measured rotation phase of the spindle motor and a phase of the commutation sequence;
and

adjust a frequency of the oscillator based on the phase error.

US Pat. No. 10,039,219

METHOD AND DEVICES FOR PICKING AND PLACING WORKPIECES INTO DEVICES UNDER MANUFACTURE USING DUAL ROBOTS

Western Digital Technolog...

1. A device, comprising:at least one controller;
a track defining a common X-axis;
a first robot, controlled by the at least one controller, comprising:
a first X-axis driven element configured for movement along the track defining the common X-axis;
a first Z-axis driven element, attached to the first X-axis driven element, configured for selective movement parallel to a Z-axis and along the common X-axis;
a first Y-axis driven element, attached to the first Z-axis driven element, configured for selective movement parallel to a Y-axis, the Z-axis and along the common X-axis; and
a first end-effector, attached to the first Y-axis driven element and configured for acting upon a device under manufacture; and
a second robot, controlled by the at least one controller, comprising:
a second X-axis driven element configured for movement along the track defining the common X-axis;
a second Z-axis driven element, attached to the second X-axis driven element, configured for selective movement parallel to the Z-axis and along the common X-axis;
a second Y-axis driven element, attached to the second Z-axis driven element, configured for selective movement parallel to the Y-axis, the Z-axis and along the common X-axis; and
a second end-effector, attached to the second Y-axis driven element and configured for acting upon a device under manufacture; and
wherein the device further comprises:
a workpiece supply tray configured to support a supply of workpieces to be integrated into the device or devices under manufacture; and
at least one workpiece supply tray motor configured to relocate the workpiece supply tray.

US Pat. No. 9,542,966

DATA STORAGE DEVICES AND METHODS WITH FREQUENCY-SHAPED SLIDING MODE CONTROL

Western Digital Technolog...

1. A data storage device, comprising:
a microactuator configured to position a head relative to a disk;
a coarse actuator configured to position the microactuator relative to the disk; and
a servo controller configured to generate an adjusted position error signal based on a position error signal and an estimated
microactuator position signal, and configured to filter the adjusted position error signal with a shaping filter to generate
a filtered position error signal, and configured to provide sliding mode control of the coarse actuator based at least partially
on the filtered position error signal;

wherein the shaping filter is configured to provide frequency dependent filtering of the adjusted position error signal to
generate the filtered position error signal.

US Pat. No. 9,417,810

POWER MANAGEMENT FOR A DATA STORAGE SYSTEM

Western Digital Technolog...

1. A data storage system comprising:
a plurality of storage devices, each of the storage devices in the plurality of storage devices comprising a plurality of
logical block addresses (“LBAs”) and configured to be in a first operating mode or a second operating mode, wherein the first
operating mode comprises an active mode where the storage device is ready to send or receive data and the second operating
mode comprises a reduced power mode relative to the first operating mode; and

a bridge configured to be connected to the plurality of storage devices and a host configured to transmit host commands to
the bridge, wherein the bridge is further configured to:

receive a first host command for the data storage system to enter the first operating mode;
prevent the first host command from reaching the plurality of storage devices so that the plurality of storage devices remains
in the second operating mode;

receive a second host command to access an LBA;
determine a storage device in the plurality of storage devices where the LBA is located; and
indicate only to the storage device where the LBA is located, that the storage device where the LBA is located should transition
from the second operating mode to the first operating mode.

US Pat. No. 9,304,560

BACKUP POWER FOR REDUCING HOST CURRENT TRANSIENTS

Western Digital Technolog...

1. A data storage device (DSD) including a power supply from a host, the DSD comprising:
a charge storage element for supplying power for the DSD;
current sense circuitry for detecting a current transient on the power supply from the host; and
a current regulating circuit configured to:
determine whether the current transient exceeds a current threshold that corresponds to a current limit of the power supply
from the host;

when the current transient exceeds the current threshold, cause the DSD to draw power from the charge storage element; and
stop power drawn from the charge storage element.

US Pat. No. 9,263,136

DATA RETENTION FLAGS IN SOLID-STATE DRIVES

Western Digital Technolog...

1. A data storage device comprising:
a non-volatile memory array comprising a plurality of non-volatile memory devices; and
a controller configured to:
write data to a memory unit of the non-volatile memory array;
write a value to a memory indicating a number of bits of the written data programmed in a first of a plurality of logical
states;

read the written data from the non-volatile memory array;
determine a number of bits having the first of the plurality of logical states in the read data;
determine a difference between the number of bits of the written data programmed in the first logical state and the number
of bits having the first logical state in the read data; and

schedule a data refreshing operation for the non-volatile memory array based at least in part on the difference.

US Pat. No. 9,208,825

DISK DRIVE HAVING A CONFORMAL PERIPHERAL FOIL SEAL HAVING AN OPENING COVERED BY A CENTRAL METAL CAP

Western Digital Technolog...

1. A hermetically sealed disk drive comprising:
a disk drive enclosure including
a disk drive base with a bottom face and four side faces, and
a top cover, wherein the disk drive enclosure has a top face that includes an upper surface of the top cover and an upper
surface of the disk drive base;

a peripheral foil seal including
a continuous metal foil overlapping each of the four side faces and having a first opening therethrough that overlies the
upper surface of the top cover, and

a first continuous adhesive layer coating the continuous metal foil,
the peripheral foil seal conforming to the disk drive enclosure and being adhered to the top face and to each of the four
side faces by the first continuous adhesive layer; and

a central metal cap completely covering the first opening and being adhered to the upper surface of the top cover through
the first opening by a second continuous adhesive layer, the central metal cap being thicker than the continuous metal foil;

wherein the disk drive enclosure is helium-filled.

US Pat. No. 9,195,293

USER CONTROLLED DATA STORAGE DEVICE POWER AND PERFORMANCE SETTINGS

Western Digital Technolog...

19. A data storage device (DSD) in communication with a host, the DSD comprising:
a memory storing power and performance settings for the DSD; and
a processor configured to:
receive a power management command from the host, wherein the power management command is based on an evaluation by the host
of an intercepted host initiated power management (HIPM) command that is cancelled or altered to form the power management
command; and

configure the DSD in accordance with the power management command received from the host.

US Pat. No. 9,153,283

DATA STORAGE DEVICE COMPENSATING FOR HYSTERETIC RESPONSE OF MICROACTUATOR

Western Digital Technolog...

1. A data storage device comprising:
a disk;
a head;
a microactuator configured to actuate the head over the disk; and
control circuitry configured to:
generate a control signal applied to the microactuator based on an input sequence u(k);
update a Preisach bit map bj based on the input sequence u(k), wherein the Preisach bit map bj corresponds to a Preisach plane modeling a hysteretic response of the microactuator;

generate a current compensation value yi based on an update value generated based on:


where hj represents a slice of the Preisach plane and bj is an update bit map based on at least part of the Preisach bit map bj; and

combine a current input ui and the current compensation value yi to generate the control signal applied to the microactuator.

US Pat. No. 9,143,929

METHODS AND DEVICES CONFIGURED FOR IP ADDRESS CONFLICT DETECTION AND RESOLUTION UPON ASSIGNMENT OF WAN IP ADDRESS

Western Digital Technolog...

1. A method of configuring a device couple to a network gateway, comprising:
upon the device being assigned a Wide Area Network (WAN) Internet Protocol (IP) address by the gateway device, the device
iteratively:

determining whether a LAN IP address of the device conflicts with the assigned WAN IP address by determining whether the LAN
IP address of the device is on a same subnet as the WAN IP address assigned to device;

determining whether the assigned WAN IP address is within a predetermined secondary LAN IP address range;
changing the LAN IP address of the device to a different subnet if the assigned WAN IP address is within the predetermined
secondary address range; and

changing the LAN IP address of the device to a host number within the predetermined secondary IP range if the assigned WAN
IP address is not within the predetermined secondary LAN IP address range.

US Pat. No. 9,361,939

DATA STORAGE DEVICE CHARACTERIZING GEOMETRY OF MAGNETIC TRANSITIONS

Western Digital Technolog...

1. A data storage device comprising:
a disk comprising servo information and a reference pattern comprising a plurality of magnetic transitions;
a head; and
control circuitry configured to:
process the servo information on the disk to actuate the head over the disk;
sample a read signal from the head as the head moves across a width of the reference pattern at a substantially constant velocity
to generate signal samples; and

process the signal samples to characterize a two-dimensional geometry of the magnetic transitions.

US Pat. No. 9,343,084

SYSTEMS AND METHODS FOR CORRECTING SLIDER PARALLELISM ERROR USING COMPENSATION LAPPING

Western Digital Technolog...

1. A system for correcting slider parallelism, the system comprising:
a lapping support comprising a ring shape having a centerline, the ring shape comprising at least one mounting surface being
flat and having a preselected mounting angle such that a line normal to the at least one mounting surface is not parallel
to the centerline of the ring shape;

a rowbar comprising a plurality of magnetic transducers spaced apart along a length of the rowbar; and
a lapping plate configured to lap the rowbar, the lapping plate comprising a flat lapping surface, wherein the lapping support
is positioned such that a line normal to the lapping surface is parallel to the centerline of the ring shape,

wherein the rowbar is mounted to the at least one mounting surface, and
wherein the rowbar is configured to be brought into contact with the lapping surface.

US Pat. No. 9,298,380

DATA STORAGE DEVICE WITH SELECTIVE WRITE TO A FIRST STORAGE MEDIA OR A SECOND STORAGE MEDIA

Western Digital Technolog...

1. A device comprising:
a first storage media; and
a controller configured to:
generate a first operational metric which is updated at a first frequency and a second operational metric which is updated
at a second frequency different than the first frequency;

receive a write command to write data to the first storage media; and
divert the write command to write data away from the first storage media when a combined metric, generated based on the first
operational metric and the second operational metric exceeds a threshold related to a risk of harm to the first storage media
or data loss.

US Pat. No. 9,236,071

ETCHING CONTINUOUS PERIODIC PATTERN ON A SUSPENSION TO ADJUST PITCH AND ROLL STATIC ATTITUDE

Western Digital Technolog...

1. A method of manufacturing a suspension for a head of a data storage device, the method comprising etching at least one
continuous cycle of a periodic pattern on the suspension, wherein a first part of the continuous cycle adjusts a pitch static
attitude (PSA) of the suspension and a second part of the continuous cycle adjusts a roll static attitude (RSA) of the suspension.

US Pat. No. 9,159,344

DISK DRIVE READ CIRCUIT COMPRISING AN AC COUPLED SENSE AMPLIFIER FOR AMPLIFYING A READ SIGNAL

Western Digital Technolog...

1. A disk drive read circuit comprising:
a read element for generating a read signal; and
a sense amplifier comprising an input terminal coupled through a first capacitor to the read element and an output terminal
coupled through a second capacitor to a first end of a transmission line, wherein:

a second end of the transmission line is coupled to a preamplifier; and
the sense amplifier is for amplifying the read signal,
wherein the transmission line provides at least one of a bias signal to the read element and power to the sense amplifier.

US Pat. No. 9,158,366

THERMAL CONTROL OF A STORAGE DEVICE RECEIVING A LIMITED AMOUNT OF POWER

Western Digital Technolog...

1. An electronic device comprising:
a thermal reduction device; and
a storage device electrically connected to the thermal reduction device comprising:
a media;
a channel configured to perform data operations on the media;
a power input interface configured to receive power for consumption by the storage device from an available average amount
of power, wherein the received power reduces the available average amount of power, and the available average amount of power
is no greater than a maximum average power threshold;

a thermal sensor configured to generate thermal data corresponding to a temperature of the storage device; and
a thermal control unit configured to activate or deactivate a power savings mode for the storage device based at least on
the thermal data, and to activate or deactivate the thermal reduction device based at least on the thermal data,

wherein the power savings mode affects an operation of the channel,
when the power savings mode is deactivated, the storage device is configured to consume an average amount of power such that
the available average amount of power is insufficient to operate the thermal reduction device, and

when the power savings mode is activated, the storage device is configured to consume a reduced average amount of power such
that the available average amount of power is sufficient to operate the thermal reduction device;

wherein the storage device is configured to consume a first average amount of power when the power savings mode is deactivated
and to consume a second average amount of power when the power savings mode is activated, wherein the second average amount
of power is less than the first average amount of power.

US Pat. No. 9,652,198

FIFO BUFFER CLEAN-UP

Western Digital Technolog...

1. A device comprising:
a controller configured to:
receive a first data entry over a first input port;
store the first data entry in a first data structure in a memory;
store a second data entry corresponding to the first data entry in a second data structure in the memory, wherein the second
data structure is separate from the first data structure, and wherein entries of the second data structure include a valid
bit field; and

indicate, using the valid bit field of the second data entry in the second data structure, that the first data entry in the
first data structure is valid.

US Pat. No. 9,626,373

OPTIMIZING DATA BLOCK SIZE FOR DEDUPLICATION

Western Digital Technolog...

1. A computer-implemented method for determining a first data block size for deduplicating a file type, the method comprising:
constructing a function relating a plurality of compression ratios to a plurality of test data block sizes, wherein a compression
ratio of the plurality of compression ratios is calculated by transforming a file of the file type using a deduplication technology
and a test data block size of the plurality of test data block sizes;

determining a maximum compression ratio of the function;
choosing a test data block size associated with the maximum compression ratio to be the first data block size for the file
type; and

deduplicating a data block of the first data block size based on a sliding window, wherein deduplicating the data block comprises:
calculating a first hash value to identify a potential data block; and
calculating a second hash value to identify the duplicate data block,
wherein a beginning of the sliding window is set at an end of a duplicate data block when the duplicate data block is detected,
and wherein the sliding window moves backwards when the duplicate data block is not detected.

US Pat. No. 9,501,393

DATA STORAGE SYSTEM GARBAGE COLLECTION BASED ON AT LEAST ONE ATTRIBUTE

Western Digital Technolog...

1. A method for managing data in a data storage system including a host and at least one Data Storage Device (DSD) including
a plurality of zones for storing data, the method comprising:
assigning one or more zones of the plurality of zones as a destination portion in the at least one DSD for storing data resulting
from a garbage collection operation;

assigning multiple remaining zones of the plurality of zones as at least one logical volume used by the host for storing data,
wherein the one or more zones assigned as the destination portion are outside of the at least one logical volume;

identifying, based on at least one attribute defined by the host, a source portion for the garbage collection operation from
a plurality of source portions in the multiple remaining zones assigned as the at least one logical volume; and

performing garbage collection of data in the source portion into the destination portion.

US Pat. No. 9,361,947

HARD DISK DRIVE MOTOR CUP SUPPORT

Western Digital Technolog...

1. A method of reducing deflection of a base plate of a hard disk drive device housing,
the method comprising:
mounting a data storage device with a motor and spindle with one or more storage media components mounted on the spindle positioned
within a first housing into a second housing; and

interposing a shock support between the base plate of the first housing and the second housing so that shocks are at least
partially transmitted between the first housing and the second housing via the shock support wherein the shock support is
sized and interposed so that the cross-sectional area of the shock support overlaps the cross-sectional area of a motor that
drives the spindle and so that the shock support contacts the base plate substantially over its entire cross-sectional area
wherein the shock support is formed of a resilient material that is partially pre-compressed between the first and second
housing when the data storage device is not experiencing shocks.

US Pat. No. 9,280,482

METHODS AND SYSTEMS FOR PROVISIONING A BOOTABLE IMAGE ON TO AN EXTERNAL DRIVE

Western Digital Technolog...

1. A method of provisioning a bootable image onto a portable storage device, wherein the portable storage device comprises
a volatile write cache, said method comprising:
initiating write cache disguising in a portable storage device;
receiving, from a host, a write command including write data for a bootable image;
writing the write data to a volatile write cache of a portable storage device;
provide a signal to the host indicating completion of the write command;
receiving, from the host, a cache flush command;
in response to receiving the cache flush command, disguising write caching of the write data in the volatile write cache at
least in part by providing a response to the host that falsely indicates that the write data has been flushed from the volatile
write cache without writing the write data to non-volatile memory of the portable storage device in response to the cache
flush command;

discontinuing write cache disguising in the portable storage device after a predetermined period; and
after said discontinuing, flushing the write data from the volatile write cache.

US Pat. No. 9,171,560

SLOPING TRANSITION ON A RAMP OF A HARD DISK DRIVE

Western Digital Technolog...

1. A ramp for a hard disk drive (HDD), comprising:
a ramp body comprising a head separator fin, a gimbal limiter adjacent to the head separator fin which is thicker than the
head separator fin, and a first chamfer at a transition between a first surface of the gimbal limiter and a first surface
of the head separator fin.

US Pat. No. 9,152,490

DETECTION OF USER BEHAVIOR USING TIME SERIES MODELING

Western Digital Technolog...

1. A method of predicting future access of a storage device, said method comprising:
determining respective time intervals between each access request to any subsequent access request of the storage device;
arranging the respective time intervals in a matrix;
identifying a pattern in the respective time intervals, including determining first set of intervals occurring in a column
of the matrix that correspond to a second set of intervals occurring in a row of the matrix;

predicting a next access request based on the pattern in the respective time intervals; and
proactively activating the storage device based on the predicted next access request.

US Pat. No. 9,454,989

DISK DRIVE ADJUSTING ESTIMATED SERVO STATE TO COMPENSATE FOR TRANSIENT WHEN CROSSING A SERVO ZONE BOUNDARY

Western Digital Technolog...

4. A method of operating a disk drive, the disk drive comprising a head actuated over a disk comprising a plurality of servo
sectors defining a plurality of servo tracks, and a plurality of read channels, wherein each read channel comprises an equalizer
configured to equalize signal samples of the second read signal to generate equalized samples, the servo tracks form a plurality
of servo zones, and a servo data rate of servo sectors in a first servo zone is different than a servo data rate of servo
sectors in a second servo zone, the method comprising:
receiving a first read signal from the head while reading servo data from the servo sectors;
programming each read channel with a unique configuration to process the first read signal in parallel, wherein each configuration
corresponds to a servo data rate of a respective servo zone;

receiving a second read signal from the head while reading servo data from the disk; and
programming the equalizer of each read channel with a unique configuration to process the second read signal in parallel,
wherein each configuration has a different propensity to recover the servo data from the equalized samples.