G11B20/10055

Machine learning-based read channel data detection

Technology for improved data detection using machine learning may include a method in which an analog read signal comprising data read from a non-transitory storage medium of the data storage device is received. The analog read signal is processed into a plurality of digital samples. A digital sample from the plurality of digital samples is classified into a category from a plurality of categories using a machine learning algorithm for at least some of the plurality of digital samples. The plurality of digital samples is then decoded based on at least some of the predicted categories.

Phase locking multiple clocks of different frequencies

Systems and methods are disclosed for phase locking multiple clocks of different frequencies. In certain embodiments, an apparatus may be configured to downsample a first clock having a first frequency and a second clock having a second frequency into downsampled clocks having the same frequency. The apparatus may adjust a frequency of the second clock so that the downsampled clocks are phase aligned. The apparatus may reset counters of the divider circuits that perform the downsampling so align them to a counter for the first clock. A counter for the second clock may also be reset to align with the counter for the first clock. The synchronized clocks may be applied in data storage operations, such as self-servo writing operations, where the first clock may be a read clock and the second clock may be a write clock.

DECODING DEVICE AND DECODING METHOD
20200366319 · 2020-11-19 ·

Deterioration of convergence performance or operational stability due to an increase in constraint length is suppressed when coefficients are updated, so that decoding performance is improved. A decoding device according to the present technology includes an adaptive equalization unit that performs adaptive equalization, an adaptive maximum likelihood decoding unit that causes an identification point of maximum likelihood decoding to adaptively follow a characteristic of an input signal, a target waveform generation unit that, by convoluting a partial response coefficient into a decoded value, generates an equalization target waveform of the adaptive equalization which is performed by the adaptive equalization unit, an error signal generation unit that generates, as an equalization error signal, an error signal between the equalization target waveform and an equalized signal, and a coefficient updating unit that, through least-square-method computation for minimizing a correlation between the decoded value and the equalization error signal, updates the partial response coefficient which is used by the target waveform generation unit to generate the equalization target waveform.

Magnetic tape reading apparatus and a magnetic tape reading method
10789981 · 2020-09-29 · ·

A magnetic tape reading apparatus includes a reading element unit which includes: a plurality of reading elements which are disposed in a state of being adjacent to each other and each of which reads data by a linear scanning method from a specific track region including a reading target track in a track region included in a magnetic tape; and an extraction unit which performs a waveform equalization process according to a deviation amount between positions of the magnetic tape and the reading element unit, with respect to each reading result for each reading element, to extract data derived from the reading target track from the reading result.

Multi-signal realignment for changing sampling clock

An apparatus may include a circuit configured to receive first and second samples of an underlying data from respective first and second sample periods and which correspond to respective first and second sensors, a phase control value may have first and second values during respective first and second sample periods. The phase control value may be a control value for a sample clock signal. The circuit may also determine a difference in the phase control value between the first value and the second value. The circuit may then digitally interpolate the first and second samples to produce a phase shifted first and second samples where the digital interpolation of at least one of the first and second samples mat be at least in part based on the difference in the phase control value to compensate for a phase misalignment between the first sample and the second sample.

Approximated parameter adaptation

An apparatus can include a circuit configured to process an input signal using a set of channel parameters. The circuit can produce, using a first adaptation algorithm, a first set of channel parameters for use by the circuit as the set of channel parameters in processing the input signal. The circuit can further approximate a second set of channel parameters of a second adaptation algorithm for use by the circuit as the set of channel parameters in processing the input signal based on the first set of channel parameters and a relationship between a third set of channel parameters generated using the first adaptation algorithm and a fourth set of channel parameters generated using the second adaptation algorithm. In addition, the circuit can perform the processing of the input signal using the second set of channel parameters as the set of channel parameters.

Magnetic tape apparatus

A magnetic tape apparatus, in which full widths at half maximum of spacing distribution measured by optical interferometry regarding a surface of a magnetic layer before and after performing a vacuum heating with respect to the magnetic tape are greater than 0 nm and equal to or smaller than 15.0 nm, a difference between spacings measured by optical interferometry regarding the surface of the magnetic layer before and after performing the vacuum heating is greater than 0 nm and equal to or smaller than 12.0 nm, and the extraction unit performs a waveform equalization process according to a deviation amount between positions of the magnetic tape and the reading element unit, with respect to each reading result for each reading element, to extract data derived from the reading target track from the reading result.

Hybrid timing recovery

An apparatus may include a circuit configured to receive a first phase control value of a phase control value signal, generate a first phase interpolator control signal value of a phase interpolator control signal and generate a first digital interpolator control signal value of a digital interpolator control signal. The apparatus may further be configured to phase interpolate a clock signal based on the first phase interpolator control signal value to produce a phase shifted clock signal and digitally interpolate a digital sample based on the first digital interpolator signal value to produce a phase shifted digital sample having an effective phase based on the first phase control value, the digital sample generated using the phase shifted clock signal as a sample clock.

Head delay calibration and tracking in MSMR systems

Systems and methods are disclosed for head delay calibration and tracking multi-sensor magnetic recording (MSMR) systems. In certain embodiments, an apparatus may comprise a first reader and a second reader configured to simultaneously read from a single track of a data storage medium, the first reader offset from the second reader so that the first reader and the second reader detect a same signal pattern offset in time. The apparatus may further comprise a circuit configured to determine a relative offset between the first reader and the second reader, including setting a fixed delay for a first signal from the first reader, setting a second delay for a second signal from the second reader, and adjusting the second delay to align the second signal to the first signal using a timing loop, with the first signal used as a reference signal.

DATA PATH DYNAMIC RANGE OPTIMIZATION
20200065262 · 2020-02-27 · ·

Systems and methods are disclosed for full utilization of a data path's dynamic range. In certain embodiments, an apparatus may comprise a circuit including a first filter to digitally filter and output a first signal, a second filter to digitally filter and output a second signal, a summing node, and a first adaptation circuit. The summing node combine the first signal and the second signal to generate a combined signal at a summing node output. The first adaptation circuit may be configured to receive the combined signal, and filter the first signal and the second signal to set a dynamic amplitude range of the combined signal at the summing node output by modifying a first coefficient of the first filter and a second coefficient of the second filter based on the combined signal.