Abstract: A method of testing a dynamic write field of a recording head includes preparing a test magnetic medium and recording a write signal on the test magnetic medium with the write signal being set at a first write parameter and a second write parameter. An average of multiple read-back signals of the recorded write signal are captured to determine an average amplitude of the read-back signals. The recording of the write signal on the test magnetic medium and the capturing of the average of multiple read-back signals of the recorded write signal are repeated to determine the average amplitude of the read-back signals by fixing the first write parameter of the write signal and changing the second write parameter of the write signal until the average amplitude of the read-back signals saturates.

Abstract: Apparatus and method for managing data in a hybrid data storage device. In some embodiments, the storage device has a hard disc drive (HDD) controller circuit coupled to non-volatile rotatable storage media and a solid state drive (SSD) controller circuit coupled to non-volatile solid state memory. A local volatile memory has separate HDD and SSD partitions respectively accessible by the HDD and SSD controller circuits. A top level controller circuit performs a cleaning operation to transfer a data set from the non-volatile solid state memory to the rotatable storage media by issuing a read command to the HDD controller circuit to retrieve the data set to the HDD partition, transferring the data set from the HDD partition to the SSD partition, and issuing a write command to the SSD controller circuit to write the data set from the SSD partition to the non-volatile solid state memory.

Abstract: In a method, read signals from each of a plurality of read transducers of a data head are buffered for each of a plurality of cross-track positions of the head relative to a data track. The buffered read signals are processed to establish a quality metric for each of the read signals and at least one combination read signal comprising at least two of the read signals. A data recovery cross-track position and a reader configuration comprising one or more of the read transducers are identified based on the quality metrics. A data read operation is then performed with the data head in the data recovery cross-track position using the read signals from the identified reader configuration.

Abstract: Methods of forming a NFT the methods including forming a hard mask positioned over at least a portion of the rod, the hard mask including at least one layer; patterning a resist mask over the hard mask, the resist mask having an edge positioned over at least a portion of the rod; etching a portion of the hard mask to expose a back edge of the rod and to form a back edge of the hard mask, wherein the back edge of the rod is equivalent to the back edge of the peg; and wherein a forward portion of the rod which is the portion of the rod forward of the back edge is covered by the hard mask; forming a disc mask including a void configured to form a disc of a NFT, the disc mask being formed over at least a portion of the hard mask so that the exposed back edge of the rod is within the void configured to form the disc; etching an area exposed in the void of the disc mask to remove both a rear portion of the rod and the surrounding dielectric up to the back edge of the hard mask edge; depositing a disc material in th

Abstract: An apparatus may include a circuit configured to generate a set of first ADC samples based on a first signal associated with a first read head position and a failed segment and to generate a set of second ADC samples based on a second signal associated with a second read head position and the failed segment. The circuit may then generate, by a MISO equalizer, a set of equalized ADC samples based on the set of first ADC samples and the set of second ADC samples.

Abstract: Provided herein are apparatuses and methods, including patterning a first set of features in a servo zone to form a patterned servo zone while a first mask protects a data zone from the patterning. The first mask may be removed from the data zone. The apparatuses and methods may further include patterning a second set of features in the data zone to form a patterned data zone while a second mask protects the patterned servo zone from the patterning.

Abstract: A data reader may have a magnetoresistive stack consisting of at least magnetically free and magnetically fixed structures with the magnetically fixed structure set to a first magnetization direction by a pinning structure separated from an air bearing surface by a front shield portion of a magnetic shield. The pinning structure can meet the front shield portion with a planar sidewall angled at 10° or less with respect to the ABS.

Abstract: The present disclosure relates to examples of controlling recycling of blocks of memory. In one example implementation according to aspects of the present disclosure, a method comprises allocating at least one block of memory selected from a subset of blocks to be written in accordance with an equalizing technique to equalize a variation between blocks of memory based on at least one factor. The method further comprises resupplying the subset of blocks.

Abstract: The disclosure is related to systems and methods of managing data storage in a memory device. In a particular embodiment, a method is disclosed that includes receiving, in a data storage device, at least one data packet that has a size that is different from an allocated storage capacity of at least one physical destination location on a data storage medium in the data storage device for the at least one data packet. The method also includes storing the at least one received data packet in a non-volatile cache memory prior to transferring the at least one received data packet to the at least one physical destination location.

Abstract: A preamplifier circuit can include a control line dedicated to receive a control signal that corresponds to indicating a specific register of the preamplifier circuit, which can allow the preamplifier to switch between utilizing two or more registers to control a current output of the preamplifier circuit. The preamplifier circuit may also have a serial input to program multiple registers of the preamplifier circuit in a serial fashion. In some embodiments, the current output may be a laser bias current. The preamplifier may adjust an output current that drives a laser emitter based on a control signal indicating which specific registers controls the output current. Further, a controller, such as a system-on-chip controller, may selectively vary the control signal to affect the current output of the preamplifier circuit. These systems and methods may be particularly useful for lasers and heat-assisted magnetic recording (HAMR).

Abstract: A method includes performing an integration test on executable software units. The integration test fails and identifies a symptomatic executable software unit at which the failure of the integration test is detected. One or more modified source code files, including instructions likely responsible for the failure of the integration test, are located from a plurality of modified source code files. The location involves searching a binary change database for change history records relating to both the plurality of modified source code files and the executable software units. Degrees of functional interaction between portions of modified source code files corresponding to the change history records and portions of a source code file corresponding to the symptomatic executable software unit are determined. Based on this determination, the modified source code file(s) including the instructions likely responsible for the failure of the integration test are identified.

Abstract: An apparatus comprises a thermal sensor configured to interact with a magnetic recording disk. A head-disk interface is defined between the thermal sensor and the disk. A power supply is coupled to the thermal sensor and configured to supply a bias power to the thermal sensor between a low power and a high power. A processor is coupled to the thermal sensor and configured to determine a slope of a resistance response of the thermal sensor. The processor is further configured to detect a change in the slope relative to a baseline slope. The slope change indicates increased heat sinking between the thermal sensor and the disk due to the presence of contaminant buildup at the head-disk interface.

Abstract: Log likelihood ration (LLR) values that are computed in a flash memory controller during read retries change over time as the number of program-and-erase cycles (PECs) that the flash memory die has been subjected to increases. Therefore, in cases where an LLR table is used to provide pre-defined, fixed LLR values to the error-correcting code (ECC) decoding logic of the controller, decoding success and the resulting BER will degrade over time as the number of PECs to which the die has been subjected increases. In accordance with embodiments, a storage system, a flash memory controller for use in the storage system and method are provided that periodically measure the LLR values and update the LLR table with new LLR values. Periodically measuring the LLR values and updating the LLR table with new LLR values ensures high decoding success and a low BER over the life of the flash memory die.

Abstract: A three dimensional magnetic recording media can consist of a coupling layer disposed between first and second vertically stacked recording layers. The coupling layer can provide exchange or antiferromagnetic coupling and allow the respective recording layers to be individually heat selected to different first and second coupling strengths through application of heat from a heat source.

Abstract: A solid-immersion mirror has two reflective portions surrounding a focal region. A thermal sensor that senses temperature as a function of resistance is proximate at least one of the two reflective portions of the solid-immersion mirror. A near-field transducer is located proximate the focal region of the solid-immersion mirror. The near-field transducer directs optical energy to a magnetic recording medium.

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

Abstract: A data storage enclosure may house at least two data storage devices and consist of a first electrical connector and a latch feature. The first electrical connector may be aligned with a second electrical connector of a data storage rack. The latch feature can be configured to contact a frame of the data storage rack to prevent the first and second electrical connectors from contacting until a lever of the latch feature is activated.

Abstract: Method and apparatus for managing a solid state memory, such as but not limited to a NAND flash memory. In some embodiments, a storage device includes a non-volatile solid state memory and a control circuit configured to transfer user data between the memory and a host device. The control circuit maintains, in a local memory, a data structure indicative of measured readback error rates associated with memory locations in the memory in relation to erasure counts associated with the memory locations. The control circuit retires a subset of the memory locations identified by the data structure from further availability to store user data from the host device responsive to the measured readback error rates, and responsive to the erasure counts of said memory locations indicating the memory has reached an end of life (EOL) condition.

Abstract: Provided herein is an apparatus including a photon emitter configured to emit photons onto a surface of an article. In addition, the apparatus includes a photon detector array configured to receive photons scattered from surface features and magnetic features of the article. The photon detector array is configured to provide information for mapping the magnetic features.

Abstract: Provided herein is a method, including forming a first template including a first pattern, wherein forming the first template includes self-assembly of diblock copolymers guided by an initial pattern; forming a second template including a second pattern, wherein the second pattern corresponds to a servo pattern; and forming a master template from the first template, wherein the master template includes one or more portions of the first pattern combined with the second pattern.