| Patent application number | Description | Published |
|---|
| 20080278837 | FREQUENCY, PHASE, AND GAIN ESTIMATION TECHNIQUE FOR USE IN A READ CHANNEL RECEIVER OF A HARD DISK DRIVE - One or more methods and systems are presented for performing gain and timing acquisition of data read from one or more data sectors of a hard disk drive. The gain and timing information may be used to synchronize a read channel receiver of the hard disk drive to the data read from the data sector(s). In a representative embodiment, the one or more methods comprises determining one or more frequency and phase offsets using one or more preambles of one or more data sectors residing in a hard disk drive. In a representative embodiment, the gain of the one or more preambles may be determined. In another representative embodiment, the one or more systems used to determine one or more phase and frequency offsets, and amplitudes, comprise hardware and/or software capable of utilizing a sequence of consecutive samples provided by one or more preambles of one or more data sectors. | 11-13-2008 |
| 20080320369 | DATA RETRIEVAL FROM A STORAGE DEVICE USING A COMBINED ERROR CORRECTION AND DETECTION APPROACH - One or more methods and systems of effectively retrieving data stored in a media of a storage device are presented. The one or more methods and systems are implemented by way of correcting and detecting errors using a multi-stage decoding process. In one embodiment, the storage device comprises a magnetic hard drive. In one embodiment, the system and method applies an encoding/decoding technique that allows error correction and detection to be performed over a number of successive decode stages or processing stages. Use of the system and method increases the maximum number of symbol errors that may be corrected in an encoded codeword, providing an improvement in data recovery. | 12-25-2008 |
| 20110090734 | METHODS AND APPARATUS FOR STORING DATA IN A MULTI-LEVEL CELL FLASH MEMORY DEVICE WITH CROSS-PAGE SECTORS, MULTI-PAGE CODING AND PER-PAGE CODING - Methods and apparatus are provided for storing data in a multi-level cell flash memory device with cross-page sectors, multi-page coding and per-page coding. A single sector can be stored across a plurality of pages in the flash memory device. Per-page control is provided of the number of sectors in each page, as well the code and/or code rate used for encoding and decoding a given page, and the decoder or decoding algorithm used for decoding a given page. Multi-page and wordline level access schemes are also provided. | 04-21-2011 |
| 20110216586 | Methods And Apparatus For Intercell Interference Mitigation Using Modulation Coding - Methods and apparatus are provided for intercell interference mitigation using modulation coding. During programming of a flash memory, a modulation encoding is performed that selects one or more levels for programming the flash memory such that a reduced number of cells in the flash memory are programmed with a value that violates one or more predefined criteria. During a reading of a flash memory, a modulation decoding is performed that assigns one or more levels to cells in the flash memory such that a reduced number of cells in the flash memory are read with a value that violates one or more predefined criteria. The predefined criteria can be based, for example, on one or more of an amount of disturbance caused by the programmed cell; a voltage shift of a programmed cell: a voltage stored by a programmed cell; an amount of change in current through a programmed cell; and an amount of current through a programmed cell. | 09-08-2011 |
| 20110225350 | Methods and Apparatus for Soft Data Generation for Memory Devices Based Using Reference Cells - Methods and apparatus are provided for soft data generation for memory devices using reference cells. At least one soft data value is generated in a memory device by writing a known data to one or more reference cells; reading one or more of the reference cells; obtaining a read statistic based on the read one or more reference cells; and obtaining the at least one soft data value based on the obtained read statistic. The read statistics can optionally be obtained for one or more desired locations of a memory array; or for a given pattern, PATT, in one or more aggressor cells. The read statistic can optionally comprise asymmetric statistics obtained for a plurality of possible values. | 09-15-2011 |
| 20110239089 | Methods and Apparatus for Soft Data Generation for Memory Devices Using Decoder Performance Feedback - Methods and apparatus for soft data generation for memory devices using decoder performance feedback. At least one soft data value is generated in a memory device, by obtaining performance feedback from a decoder; obtaining an error statistic based on the performance feedback; and generating the at least one soft data value based on the obtained error statistic. The performance feedback comprises one or more of decoded bits, a number of erroneous bits based on data decoded by the decoder and a number of unsatisfied parity checks. | 09-29-2011 |
| 20110246136 | METHODS AND APPARATUS FOR COMPUTING A PROBABILITY VALUE OF A RECEIVED VALUE IN COMMUNICATION OR STORAGE SYSTEMS - Methods and apparatus are provided for computing a probability value of a received value in communication or storage systems. A probability value for a received value in a communication system or a memory device is computed by obtaining at least one received value; identifying a segment of a function corresponding to the received value, wherein the function is defined over a plurality of segments, wherein each of the segments has an associated set of parameters; and calculating the probability value using the set of parameters associated with the identified segment. A probability value for a received value in a communication system or a memory device can also be computed by calculating the probability value for the received value using a first distribution, wherein the first distribution is predefined and wherein a mapped version of the first distribution approximates a distribution of the received values and wherein the calculating step is implemented by a processor, a controller, a read channel, a signal processing unit or a decoder. | 10-06-2011 |
| 20110246842 | METHODS AND APPARATUS FOR APPROXIMATING A PROBABILITY DENSITY FUNCTION OR DISTRIBUTION FOR A RECEIVED VALUE IN COMMUNICATION OR STORAGE SYSTEMS - Methods and apparatus are provided for approximating a probability density function or distribution for a received value in communication or storage systems. A target distribution is approximated for a received value in one or more of a communication system and a memory device, by substantially minimizing a squared error between the target distribution of the received values and a second distribution obtained by mapping a predefined distribution, such as a Gaussian distribution, through a mapping function, wherein the second distribution has an associated set of parameters. The mapping function can be, for example, a piecewise linear function. The second distribution has a plurality of segments and each of the segments has an associated set of parameters. The associated set of parameters can be used to compute probability values, soft data values or log likelihood ratios. | 10-06-2011 |
| 20110246859 | METHODS AND APPARATUS FOR COMPUTING SOFT DATA OR LOG LIKELIHOOD RATIOS FOR RECEIVED VALUES IN COMMUNICATION OR STORAGE SYSTEMS - Methods and apparatus are provided for computing soft data or log likelihood ratios for received values in communication or storage systems. Soft data values or log likelihood ratios are computed for received values in a communication system or a memory device by obtaining at least one received value; identifying a segment of a function corresponding to the received value, wherein the function is defined over a plurality of segments, wherein each of the segments has an associated set of parameters; and calculating the soft data value or log likelihood ratio using the set of parameters associated with the identified segment. The computed soft data values or log likelihood ratios are optionally provided to a decoder. | 10-06-2011 |
