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 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: 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: 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: 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: 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 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: 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: Method and apparatus for managing data in a data storage device. In some embodiments, a non-volatile cache memory stores a sequence of pages from a host device. A non-volatile main memory has a plurality of n-level cells arranged on m separate integrated circuit dies each simultaneously accessible during programming and read operations using an associated transfer circuit, where m and n are plural numbers. A control circuit writes first and second pages from the sequence of pages to a selected set of the n-level cells coupled to a common word line on a selected integrated circuit die. The second page is separated from the first page in the sequence of pages by a logical offset comprising a plurality of intervening pages in the sequence of pages. The logical offset is selected responsive to the m number of integrated circuit dies and a delay time associated with the transfer circuits.

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.

Abstract: Method and apparatus for enhancing write current switching efficiencies during data write operations in a data storage device. In some embodiments, write data are described in the form a sequence of symbols of nT length where T is a channel clock rate and n is an integer over a selected range. Bi-directional write currents are applied to a write element to record the sequence of symbols to a storage medium. The write currents are switched between a first rail current and a second rail current for alternating symbols. The write currents are further transitioned to an intermediate current value for at least one channel clock period immediately preceding a next occurrence of a symbol boundary between an adjacent pair of symbols in the sequence.

Abstract: An apparatus includes an actuator assembly, a dampening assembly coupled to the actuator assembly, and a vibration sensor assembly coupled to the dampening assembly and coupled to the actuator assembly by way of the dampening assembly. A method includes attaching a dampening assembly to an actuator assembly and attaching a vibration sensor assembly to the dampening assembly. The dampening assembly is positioned between the vibration sensor assembly and the actuator assembly.

Abstract: A data storage device data writer may arrange a write pole to be positioned uptrack from a front shield on an air bearing surface. The front shield can consist of a lamination of a first magnetic alloy material and a second magnetic alloy material. The second magnetic alloy material may be NiFe that has 80% iron by weight.

Abstract: A method of forming a near field transducer (NFT), the method including the steps of depositing a plasmonic material; depositing an encapsulant material on at least a portion of the plasmonic material; and implanting ions into at least a portion of the plasmonic material through the encapsulant material.

Abstract: Method and apparatus for data security in a data storage device. In some embodiments, a first version of firmware is installed in a memory of the device. The firmware is used by a programmable processor to control accesses to a rotatable data recording medium on which is written pre-recorded servo positioning data used to position a data transducer. A newer, second version of the firmwave is subsequently installed in the memory to replace the first version of firmware. The second version of the firmware includes an instruction to corrupt a selected portion of the servo positioning data on the medium in order to authenticate the second version of the firmware. During a subsequent initialization of the device, host access is granted based on detection of the corruption of the selected portion of the servo positioning data.

Abstract: A write pole of a data writer may have at least one rotational milling operation conducted on a write pole blank followed by first and second static milling operations executed at different first and second angles with respect to an air bearing surface. The combination of rotational and static milling operations can form a write pole with body and tip regions defined by a continuous pole sidewall extending perpendicularly from the air bearing surface up to a body taper portion angled at approximately 14.5° with respect to the air bearing surface.

Abstract: One embodiment described herein is directed to a method involving depositing a seed layer on a substrate, the seed layer comprising A1 phase FePt with a ratio of Pt of Fe greater than 1:1. A main layer is deposited on the seed layer, the main layer comprising A1 phase FePt with a ratio of Pt to Fe of approximately 1:1. A cap layer is deposited on the main layer, the cap layer comprising A1 phase FePt with a ratio of Pt to Fe of less than 1:1. The seed, main and cap layers are annealed to convert the A1 phase FePt to L10 phase FePt having a graded FePt structure of varying stoichimetry from approximately Fe50Pt50 adjacent a lower portion of the structure proximate the substrate to Fe>50Pt<50 adjacent an upper portion of the structure opposite the lower portion.

Abstract: A data reader may have a magnetoresistive stack consisting of at least magnetically free and magnetically fixed structures. The magnetically fixed structure can be set to a first magnetization direction by a first pinning structure separated from an air bearing surface by a front shield portion of a magnetic shield. The front shield portion may be set to a different second magnetization direction by a second pinning structure.