Abstract: A storage device controller addresses consecutively-addressed portions of incoming data to consecutive data tracks on a storage medium and writes the consecutively-addressed portions to the consecutive data tracks in a non-consecutive track order. In one implementation, the storage device controller reads the data back from the consecutive data tracks in a consecutive address order in a single sequential read operation.

Abstract: An apparatus determines that phase errors have exceeded a threshold when reading data previously recorded to a heat-assisted recording medium. In response to the phase errors exceeding the threshold, remedial action is taken to prevent loss of data due changes in power applied to heat the heat-assisted recording medium when recording.

Abstract: Data is written to a magnetic recording medium of a drive using a read/write head. The read/write head has an energy source that applies a hotspot to the magnetic recording medium while recording. During the writing, a steady-state current applied to the energy source is changed by a step value. A timing error induced by the change in the steady-state current is measured based on reading back the data. A thermal gradient of the hotspot is determined based on the step value and the timing error.

Abstract: First and second different write precompensation values are associated with different first and second non-return-to-zero, inverted (NRZI) data patterns. The first and second different write precompensation values cause a predetermined phase shift to be written into test data that comprises the first and second NRZI data patterns. The test data is mitten to a recording medium of a storage device using the first and second write precompensation value. The test data is used to determine a response of the storage device to the predetermined phase shift.

Abstract: A storage device controller is configured to select one of multiple written track widths for a storage location based on a write attribute of data to be recorded at the storage location. According to one implementation, the storage device controller is further configured to select a power level for a heat-assisted magnetic recording (HAMR) device based on the write attribute.

Abstract: An apparatus and method provide for performing, using a heat-assisted magnetic recording head, multiple sequential writes to a recording medium, and recording a metric of write performance for each of the writes. The apparatus and method further provide for calculating fluctuations in the metric, detecting whether the head has a laser mode hopping problem using the metric fluctuations, and categorizing a severity of the laser mode hopping problem.

Abstract: An apparatus comprises a heat-assisted magnetic recording drive which includes an enclosure having a base and a cover. The drive includes a magnetic recording disk and a head gimbal assembly proximate one of the base and the cover. The HGA supports a slider assembly comprising a laser diode unit. The LDU projects away from the HGA towards one of the base and the cover. An arcuate channel is provided in one of the base and the cover and dimensioned to receive a distal portion of the LDU. The channel has a length that accommodates the distal portion of the LDU along a stroke of the HGA.

Abstract: An apparatus and method provide for performing, using a heat-assisted magnetic recording head, multiple sequential writes to a recording medium, and recording a metric of write performance for each of the writes. The apparatus and method further provide for calculating fluctuations in the metric, detecting whether the head has a laser mode hopping problem using the metric fluctuations, and categorizing a severity of the laser mode hopping problem.

Abstract: A read/write head has a set of components that at least include: at least one clearance actuator; at least one read transducer configured to read from a magnetic recording medium; and at least one write transducer configured to write to the magnetic recording medium. A switch network is coupled to the set of components and configured to, in response to a control signal, couple a selected sub-combination of the components to a common set of signal lines. The coupling of the selected sub-combination facilitates operation in a selected mode of the read/write head.

Abstract: A storage device controller is configured to select one of multiple written track widths for a storage location based on a write attribute of data to be recorded at the storage location. According to one implementation, the storage device controller is further configured to select a power level for a heat-assisted magnetic recording (HAMR) device based on the write attribute.

Abstract: A storage device disclosed herein stores data on a storage media using interlaced magnetic recording (IMR) and it includes a storage controller configured to determine power levels applied to the power source such that power levels applied to heat various tracks can be different from each other. An implementation of the storage device determines the track density, linear densities and power levels for even and odd tracks in IMR HAMR for the storage media.

Abstract: Systems and methods of digital automatic power control are presented. A preamplifier circuit may include a digital-to-analog converter (DAC) circuit to sample a power signal, such as a from a laser power monitor. The preamplifier may store the sample in an internal preamplifier memory. The sample may be utilized to update a current output of the preamplifier that affects the power signal. These systems and methods may be particularly useful for lasers and heat-assisted magnetic recording (HAMR), which may be utilized during a read mode or a write mode of a HAMR data storage device.

Abstract: Before writing to a heat-assisted magnetic recording medium, a current of a laser is modulated about a default threshold current level. A modulation level of an optical power sensor is measured, the optical power sensor being coupled to detect optical output of the laser in response to the modulated current. A bias current for subsequent activation of the laser is adjusted based on the modulation level of the optical power sensor.

Abstract: A storage device disclosed herein stores data on a storage media using interlaced magnetic recording (IMR) and it includes a storage controller configured to determine power levels applied to the power source such that power levels applied to heat various tracks can be different from each other. An implementation of the storage device determines the track density, linear densities and power levels for even and odd tracks in IMR HAMR for the storage media.

Abstract: A storage device includes a storage medium having a plurality of data tracks. At least one data track of the plurality of data tracks includes a number of super parity sectors. The number of super parity sectors selected for the at least one data tracks is selected based on a distance between an inner diameter of the storage medium and the data track. The number of super parity sectors provides error correction code for the at least one data track.

Abstract: A storage device includes a data degradation management module that tracks a risk of data degradation by incrementing a track write counter of a first data track responsive to each data write command to a second data track, such as a data track directly adjacent to the first data track. If a count of the track write counter exceeds a count threshold, one or more post-write scan operations are performed to assess and/or repair data degradation of the first data track.

Abstract: A storage device includes a controller that selects an offset when preparing to write data to a target data track. The offset defines a position for a write head relative to a center of the target track and is selected based on a radial position of a write head at the target data track.

Abstract: A method comprises storing a first laser current value in response to a photodetector sensing that a threshold current for a laser diode of a HAMR head has been reached, the photodetector situated proximate the laser diode. The method also comprises storing a second laser current value in response to a sensor sensing that the threshold current for the laser diode has been reached, the sensor situated away from the laser diode. The method further comprises determining a difference (delta) between the first and second laser current values, repeating the storing and determining processes during subsequent use of the laser diode, and detecting a change in the delta indicative of a malfunction of the head.

Abstract: A storage device includes a storage medium having a first set of non-adjacent data tracks having a number of super parity sectors and a second set of non-adjacent data tracks interlaced with the first set of non-adjacent data tracks. The number of super parity sectors on a data track of the first set of non-adjacent data tracks is selected based on a distance between the data track and an inner diameter of the storage medium.

Abstract: A storage device includes a storage controller configured to write a band of data tracks using a first recording method until criterion is met. The first method may be a conventional recording method. After the criterion is met, the storage controller is configured to write data to the band using a second recording method. The second recording method may be an enhanced capacity recording method such as interlaced magnetic recording (IMR) or shingled magnetic recording (SMR).