Seagate Technology Incorporated

William Michael Radich

Ara Patapoutian

Belkacem Derras

Jason Bellorado

Raman Venkataramani

Zheng Wang

Rishi Ahuja

Deepak Sridhara

Michael John Link

Marcus Marrow

Jon David Trantham

Bruce Douglas Buch

Barmeshwar Vikramaditya

Raman Venkataranmani

Mark A Gaertner

Timothy Richard Feldman

Sundararajan Sankaranarayanan

Jason Bryce Gadbois

Timothy Francis Ellis

Todd Michael Lammers

Jason Charles Jury

Robert Matousek

Kendall Hayne Fung

Rodney Blake

Guofang Xu

David H Dahlem, Jr

Raman Chatapuram Vankataramani

Fatih Erden

A cyclo-stationary characteristic of a communications channel and/or storage media is determined. The cyclo-stationary characteristic has K-cycles, K>1. Markov transition probabilities are determined that depend on a discrete phase ϕ=t mod K, wherein t is a discrete time value. An encoder to optimize the Markov transition probabilities for encoding data sent through the communications channel and/or stored on the storage media. The optimized Markov transition probabilities are used to decode the data from the communication channel and/or read from the storage media.

Markov encoder-decoder optimized for cyclo-stationary communications channel or storage media

Components are extracted from user data being read from a reader of a hard disk drive. The components collectively indicate both a magnitude and direction of a read offset of the reader over a track. The components are input to a machine-learning processor during operation of the hard disk drive, causing the machine-learning processor to produce an output. A read offset of the reader is estimated during the operation of the hard drive head based on the output of the machine learning processor. While reading the user data, a radial position of the reader over the track is adjusted via an actuator based on the estimated read offset.

Estimating read offset in a drive using machine learning

Two or more data values are received from one or more sensors of a hard disk drive. The two or more data values are indicative of a fly height of a recording head of the hard disk drive. The two or more data values are input into a machine-learning processor during operation of the hard disk drive. A fly height of the recording head during the operation of the hard drive head is adjusted based on an output of the machine learning processor.

Estimating recording head fly height using machine learning

A method includes determining an error after attempting to read, via a first read transducer and a second read transducer, a data sector in a first data track. The method further includes calculating a weight ratio associated with the data sector and determining a read offset direction of the data sector based, at least in part, on the calculated weight ratio.

Read offset calibration for error recovery

An integrated circuit includes a read/write channel and a servo controller. The read/write channel is configured to: determine, in connection with a first path, respective read errors associated with N number of the data sectors; estimate respective offset positions of the N number of the data sectors; and generate a second path based, at least in part, on the respective estimated offset positions. The servo controller is configured to cause adjustment of a position of a read transducer based on the second path.

Multi-sector read offset recovery

A hard disk drive includes a magnetic recording medium comprising data sectors along a data track, a read head arranged to read data from the data sectors, and an integrated circuit. The integrated circuit includes circuitry programmed to detect a read error associated with a first of the data sectors and continue to read data from the data sectors after the detection of the read error.

Systems and methods are disclosed for performing event timing detection for DNA sequencing. In certain embodiments, a method may comprise generating a signal based on a DNA strand passed through a nanopore sensor, sampling the signal to generate a plurality of sample values, and detecting one or more event boundaries based on the sample values, an event representing a movement of a single DNA base of the DNA strand through the nanopore sensor. Detecting the one or more event boundaries may include segmenting the plurality of sample values into multiple events to calculate an optimal total score, assigning an event value to a selected event from the multiple events based on sample values of the selected event, and providing the event value to a base caller to determine a sequence of DNA bases.

Event timing detection for DNA sequencing

A plurality of configuration sets are used with a detector coupled to a decoder. A processor is coupled to the memory registers and the detector and operable to load a first one of the configuration sets into the detector. The detector to attempts detection of the bits in the digital stream for a first iteration between the detector and the decoder using the first configuration set. After the first iteration, a second one of the configuration sets is loaded into the detector. The second configuration set is different than the first configuration set. The detector to attempts detection of the bits in the digital stream for a second iteration between the detector and the decoder using the second configuration set.

Storage device that switches detector configuration sets between decoding iterations

In one implementation, the disclosure provides a system including a detector configured to generate an output of a first log-likelihood ratio for each bit in an input data stream. The system also includes at least one look-up table providing a mapping of the first log-likelihood ratio to a second log-likelihood ratio. The mapping between the first log-likelihood ratio and the second log-likelihood ratio is non-linear. The system also includes a decoder configured to generate an output data stream using the second log-likelihood ratio to generate a value for each bit in the input data stream.

Non-linear LLR look-up tables

A method includes receiving a data signal over a multi-input multi-output (MIMO) channel. The method further includes equalizing the data signal, by an adaptive equalizer circuit having an associated target, to provide an equalized output of the data signal. As part of the method, taps of the equalizer circuit and coefficients of the target are estimated. A constraint is imposed on the coefficients of the target as part of the estimation of the coefficients of the target. A similar minimization process is used with constraint imposed on whitening filter taps associated with a DDNP detector in the MIMO channel.

Adaptive MIMO channel equalization and detection

A system may comprise a finite impulse response circuit configured to receive one or more samples of a first signal and generate an equalized signal based on the plurality of samples of the input signal and one or more updatable tap coefficients. The system may include an adaptation circuit configured to update the one or more updatable tap coefficients based on the plurality of samples of the input signal. The system may further comprise a recovery circuit configured to accumulate one or more retuning values based on the plurality of samples of the input signal and, in response to an error condition, generate one or more retuned tap coefficients for the finite impulse response circuit based on the one or more retuning values and replace the one or more updatable parameters with the one or more retuned parameters.

Channel parameter recovery

A phase-locked loop (PLL) filter of a read channel includes a filter portion having an input coupled to delay circuitry having an output. The input of the filter portion is configured to receive a phase error signal. A look-up table is coupled to the filter portion. The look-up table comprises phase coefficients and frequency coefficients associated with a plurality of phase error magnitudes. The look-up table is configured to provide one or both of a selected phase coefficient and a selected frequency coefficient based on a magnitude of the phase error signal. The PLL filter is configured to adjust a bandwidth of the filter portion using one or both of the selected phase coefficient and the selected frequency coefficient. A phase signal indicative of estimated phase disturbance is produced at the output of the delay circuitry.

Self-adapting phase-locked loop filter for use in a read channel of a heat assisted magnetic recording drive

In certain embodiments, an apparatus may comprise a circuit configured to receive a plurality of samples of an input signal. The circuit may update one or more equalizer parameters using partial zero forcing equalization. Further, the circuit may generate an equalized signal based on the plurality of samples of the input signal and the one or more equalizer parameters.

Partial zero forcing equalization

A system may include an interpolator circuit configured to receive a first signal with a first rate and to generate an interpolated signal with a second rate. The system may include a cancellation circuit configured to determine an interference component signal based on the interpolated signal. The system may further comprise an adder configured to receive a second signal with the second rate and to cancel interference in the second signal using the interference component signal to generate a cleaned signal.

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Longmont, CO, United States of America

William Michael Radich