Western Digital Technologies, Inc.

Western Digital Corporation

Cnex Labs, Inc.

Other

Avago Technologies General IP (singapore) Pte. Ltd.

Patrick J Lee

Robert L Cloke

Steven R Vasquez

Alan Armstrong

Carl Bonke

Marc E Acosta

Trinh C Bui

Joanne Wu

Stanley Chang

Manmohan K Sharma

Howard A Baumer

Steven W McLaughlin

Yiren Huang

Mark David Thomas

Alvin Jianjiang Wang

David M Hamilton

Phong Tran

William W Brown

Donna J Lee

Robert E Caddy, Jr

A computing system includes: a data block including data pages and each of the data pages includes data sectors and each of the data sectors include sector data and a sector redundancy; a storage engine, coupled to the data block, configured to: apply a first protection across the data pages, apply a second protection across the data sectors, and correct at least one of the data sectors when a sector correction with the sector redundancy failed with the first protection and the second protection.

Computing system with data protection mechanism and method of operation thereof

A computing system includes: a data block including data pages and each of the data pages includes data sectors and each of the data sectors include sector data and a sector redundancy; a storage engine, coupled to the data block, configured to: apply a first protection across the data pages includes shifted parities generated, apply a second protection across the data sectors, and correct at least one of the data sectors when a sector correction with the sector redundancy failed by selecting one of the shifted parities for the first protection and the second protection.

Computing system with shift data protection mechanism and method of operation thereof

Methods and apparatus for facilitating pre-read and/or post-read operations of a disk drive. A write command is received including a logical block address (LBA) for user data in the write command. Parity data for correcting the user data is generated by encoding the LBA with the user data. The parity data is written on a disk of the disk drive with the user data so that the LBA can be recovered using the parity data when read from the disk. When a read command is received by the disk drive, requested user data is read from a first sector. User data and parity data is read from a second sector adjacent the first sector. The parity data is used to recover an LBA for the second sector and it is determined whether to store the user data read from the second sector based on the recovered LBA.

Data access for shingled magnetic recording media

A disk drive is disclosed comprising a head actuated over a disk, wherein data is read from the disk to generate a read signal. The read signal is sampled to generate signal samples, and the signal samples are filtered with an equalizer filter to generate equalized samples. The equalized samples are filtered with a general noise whitening filter to generate general noise whitened samples. The general noise-whitened samples are filtered with a bank of data dependent noise whitening filters to generate data dependent noise whitened samples, and a data sequence is detected from the data dependent noise whitened samples.

Disk drive employing general noise whitening filter to reduce length of data dependent noise whitening filters

A disk drive is disclosed comprising a head actuated over a disk, and control circuitry comprising a read channel comprising an analog filter and an equalizer. Data is read from the disk to generate a read signal, and the analog filter filters the read signal. The filtered read signal is sampled, and the read signal samples are input into the equalizer in order to equalize the read signal samples according to a target response. A response of the read channel based on the read signal samples input into the equalizer is identified to generate an identified response. Expected samples are generated based on the identified response, wherein the expected samples correspond to the data written to the disk, and an estimated noise sequence is estimated based on the expected samples and the read signal samples.

Disk drive estimating noise in a read signal based on an identified response at the input of an equalizer

A data storage device is disclosed comprising a non-volatile memory. A write command is received comprising a first logical block address (LBA) and first user data, and a second LBA and second user data. The first LBA is mapped to a first physical block address (PBA) for addressing a first memory segment. The second LBA is mapped to a second PBA for addressing a second memory segment. First redundancy is generated in response to the first user data, second redundancy in generated in response to the second user data, and parity data is generated in response to the first and second user data. Third redundancy is generated in response to the parity data and in response to at least one of the first LBA and the first PBA and at least one of the second LBA and the second PBA.

Data storage device generating redundancy for data path protection of a parity sector

A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of data tracks. A read signal emanating from the head is sampled to generate read samples, and first log-likelihood ratios (LLRs) are generated in response to the read samples. The first LLRs are biased to generate biased LLRs, and the biased LLRs are decoded into a data sequence, wherein the biased LLRs increase an error rate of the data sequence.

Disk drive margining read channel by biasing log-likelihood ratios of an iterative decoder

A serial number detector is disclosed for detecting an encoded serial number written on a wafer. A scanner scans the wafer to generate a raster image representing the encoded serial number, and an optical character recognition (OCR) system detects a detected serial number comprising a plurality of detected data characters and a plurality of detected redundancy characters. A character-to-binary converter converts the detected data characters and the detected redundancy characters into codeword symbols. A syndrome generator generates a plurality of error syndromes in response to the codeword symbols, and an error corrector, responsive to the error syndromes, detects and corrects errors in the codeword symbols.

Using optical character recognition augmented by an error correction code to detect serial numbers written on a wafer

A storage device is disclosed comprising control circuitry. A write command is received from a host, wherein the write command comprises a host block and corresponding host block address. The host block is partitioned into a plurality of sub blocks, and a plurality of sub block addresses are generated in response to the host block address, wherein each sub block address corresponds to one of the sub blocks. Error detection code (EDC) data is generated for each sub block in response to the sub block and corresponding sub block address. Each sub block and corresponding EDC data are combined to generate a plurality of partial codewords that are written to one or more data sectors corresponding to the sub block addresses.

Storage device implementing data path protection by encoding large host blocks into sub blocks

A data storage device is disclosed that receives a read command from a host, wherein the read command comprises a read logical block address (LBA_R). A target data sector is read in response to the LBA_R to generate a read signal. The read signal is processed to detect user data and redundancy data using a soft-output detector that outputs quality metrics for the user data and redundancy data. A high quality metric is assigned to the LBA_R, and errors are corrected in the user data using an error correction code (ECC) decoder in response to the quality metrics output by the soft-output detector and the quality metrics assigned to the LBA_R.

Data storage device employing high quality metrics when decoding logical block address appended to a data sector

A disk drive is disclosed comprising a head actuated over a disk and control circuitry operable to sample a read signal emanating from the head to generate read samples. First vectors of log-likelihood ratios (LLRs) are generated in response to the read samples, wherein each vector corresponds to a nonbinary symbol q in a set of symbols. The first vectors of LLRs are biased to generate biased vectors of LLRs, and the biased vectors of LLRs are decoded into a data sequence, wherein the biased vectors of LLRs increase an error rate of the data sequence.

Disk drive margining read channel by biasing log-likelihood ratios of a nonbinary iterative decoder

An error correction system is disclosed comprising an encoder operable to generate an encoded codeword of a polynomial code over a Galois field GF(q) comprising q elements, wherein the encoded codeword comprises an input data sequence, at least one check symbol, and redundancy symbols. A decoder decodes a received codeword into the encoded codeword by correcting at least one error in the received codeword to generate a corrected codeword, evaluating at least one symbol of the corrected codeword relative to the check symbol in order to detect a shift error, and when the shift error is detected, shift the corrected codeword to correct the shift error.

Error correction code for correcting shift and additive errors

A disk drive is disclosed including a disk having a plurality of data tracks, wherein each data track includes a plurality of data sectors. A head is actuated over the disk for accessing the data sectors. A write command is received from a host, wherein the write command includes a host block and corresponding host block address. The host block is partitioned into a plurality of sub blocks, and a plurality of sub block addresses are generated in response to the host block address, wherein each sub block address corresponds to one of the sub blocks. Error detection code (EDC) data is generated for each sub block in response to the sub block and corresponding sub block address. Each sub block and corresponding EDC data are combined to generate a plurality of partial codewords that are written to the data sectors corresponding to the sub block addresses.

Disk drive implementing data path protection by encoding large host blocks into sub blocks

An adaptive transmit equalizer for equalizing digital symbols to be transmitted over a communications channel includes a transmit filter having an associated register for storing at least one filter coefficient. A tuning engine generates performance metric values based on digital symbols received through the communications channel. The tuning engine is configured to identify at least one filter coefficient based on the performance metric values using a simplex algorithm. The tuning engine is configured to communicate the at least one updated filter coefficient to the transmit filter for storage in the register.

Adaptive transmit equalizer

A communication channel is disclosed comprising a trellis sequence detector for detecting an estimated data sequence from signal sample values. A post processor detects and corrects an error event of the trellis sequence detector by remodulating the estimated data sequence into a sequence of expected sample values, computing samples errors as the difference between the expected samples and signal samples, and correlating the sample errors with error event samples. The communication channel further comprises a Reed-Solomon error correction code (ECC) decoder for decoding a Reed-Solomon codeword in the estimated data sequence in response to the detected error event.

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Foothill Ranch, CA, United States of America

Patrick J Lee