Abstract: A system including a first first-in first-out (FIFO) module, a control module, and a second FIFO module. The first FIFO module is configured to receive, from a host, (i) a first block and (ii) a first logical block address corresponding to the first block, where the first block includes first data. The control module is configured to generate a second block, where the second block includes (i) the first data and (ii) the first logical block address. The second FIFO module is configured to receive a third block from the first FIFO module, where the third block includes a second logical block address, and to determine whether the third block is different than the first block depending on whether the second logical block address included in the third block is different than the first logical block address included in the second block.

Abstract: An audio amplifier including (i) a mode controller configured to generate a control signal, and (ii) a variable-length finite impulse response (FIR) filter. The variable-length FIR filter includes (i) a first fixed-length FIR filter configured to generate a first filtered signal based on a first digital audio signal, and (ii) a second fixed-length FIR filter configured to generate a second filtered signal based on the first digital audio signal. The variable-length FIR filter also includes an output module configured to (i) select one of the first filtered signal or the second filtered signal based on the control signal, and (ii) provide the selected one of the first filtered signal or the second filtered signal as an output signal. The audio amplifier also includes an analog module configured to generate an amplified analog signal based on the output signal.

Abstract: Systems, methods, and other embodiments associated with estimating a natural sampling point from uniform sample points when generating a PWM signal are described. According to one embodiment, an apparatus includes a cross point logic configured to determine which of the samples along the analog signal are adjacent to a crossing point of a reference signal and the analog signal by identifying samples between which the crossing point occurs. The apparatus includes an interpolation logic configured to adaptively interpolate points along the analog signal that approach the crossing point by using the samples. The interpolation logic is configured to adaptively interpolate the points to refine a region between the points within which the crossing point occurs. The apparatus includes a search logic configured to search within the region to produce an estimated location of the crossing point by using the interpolated points.

Abstract: A method of writing data to a storage device that uses a first data block size, from a host system that uses a second data block size, different from the first data block size, includes receiving a request from the host system to write a host data block to the storage device, reading a storage device data block from a first location on the storage device to a buffer, where the storage device data block corresponds to the host data block, modifying the storage device data block based on the host data block, restricting writing of the modified storage device data block into the first location, and storing the modified storage device data block to a second location, different from the restricted first location. After acknowledging success of the storing, the restricting of writing of the modified storage device data block into the first location may be lifted.

Abstract: A control module includes an encoder module, a detector module, a mapping module, and a difference module. The encoder module receives data, and based on the data, generates a first code word for drives. The drives are associated with a storage system. The detector module detects an addition of a second drive. The encoder module generates a second code word for the second drive. The mapping module: maps physical locations of the data in the drives to logical locations of the first code word; assigns a predetermined value to a logical location corresponding to an unused logical location; and based on the predetermined value, assigns the unused logical location to the second drive. The difference module generates a third code word based on each of the first and second code words. The encoder module, based on the first and third code words, generates a fourth code word for all drives.

Abstract: This disclosure describes techniques for using environmental variables to improve calibration of flash memory by adapting to changing threshold-voltage distributions. These techniques effectively increase the speed and/or accuracy at which flash memory can be written or read.

Abstract: An integrated circuit including a first decoder, a second decoder, a sensor, and a controller. The first decoder generates first data by performing a first number of decoding iterations and generates second data after performing all of the first number of decoding iterations. The second decoder performs a second number of decoding iterations and generates soft information based on input samples and/or the second data. Each of the second number of decoding iterations is performed after all of the first number of decoding iterations. The first decoder generates the first data based on the soft information and/or the first data from one of the first number of decoding iterations. The sensor senses a temperature of the integrated circuit. The controller controls, based on the temperature of the integrated circuit, at least one of the first number of decoding iterations or the second number of decoding iterations.

Abstract: A memory controller includes an encoder, a modulator, and a demodulator. A nonvolatile memory includes memory cells, each programmable to one of three or more levels. According to first encoded data, the modulator programs a first subset of the memory cells to a first of the levels and a second subset of the memory cells to a second of the levels. Measurable values of the first subset are characterized by a first probability density function having a first width. Measurable values of the second subset are characterized by a second probability density function having a second width. The first width is greater than the second width. The encoder generates the first encoded data based on input data such that the first subset is smaller than the second subset. The demodulator is configured to output second encoded data in response to measurable values of the memory cells.

Abstract: An error correction system includes an iterative code that employs an interleaved component code and an embedded parity component code. In some embodiments, on the transmission side, input signals received at an input node are encoded based on the interleaved code, which encodes an interleaved version of the input data to produce a first set of codewords. At least a portion of the first set of codewords preferably is divided into a plurality of symbols which are encoded based on the embedded parity code to provide encoded data. Similarly, in some embodiments, on the receiving side, received data are detected to produce detected information and soft outputs. The detected information is decoded based on the embedded parity code to obtain decoded information. The decoded information preferably is used, together with other soft information, by an interleaved decoder to generate reliability metrics for biasing a subsequent decoding iteration.

Abstract: A channel decoder includes a demodulator, a filter, a detector module, and first and second circuits. The demodulator receives an input signal based on data read from a storage medium, and demodulates the input signal to generate a data signal. The filter generates equalized data based on the data signal. The detector module executes a Viterbi algorithm based on the equalized data to generate estimates of data originally stored in the storage medium, and based on the execution of the Viterbi algorithm, generates a first and second sets of depths. The first set of depths includes depths larger than depths in the second set of depths. The first circuit generates a first error signal based on the first set of depths. The second circuit generates a second error signal based on the second set of depths. The filter generates the equalized data based on the first and second error signals.

Abstract: An apparatus includes a circuit configured to at least one of (i) encode first data to produce encoded data or (ii) decode second data to produce decoded data. The circuit is configured to operate according to a predetermined matrix. The predetermined matrix is represented by a two-dimensional grid of elements. Each element of the predetermined matrix labeled with a hyphen corresponds to a zero matrix. Each element of the predetermined matrix labeled with a number corresponds to a respective cyclic-permutation matrix.

Abstract: A non-linear detector for detecting signals with signal-dependent noise is disclosed. The detector may choose a data sequence that maximizes the conditional probability of detecting the channel data. Since the channel may be time-varying and the precise channel characteristics may be unknown, the detector may adapt one or more branch metric parameters before sending the parameters to a loading block. In the loading block, the branch metric parameters may be normalized and part of the branch metric may be pre-computed to reduce the complexity of the detector. The loading block may then provide the branch metric parameters and any pre-computation to the detector. The detector may then calculate the branch metric associated with the input signal and output the channel data.

Abstract: Systems and methods are provided for improved designs and performance for iterative decoder systems. In some embodiments, the iterative decoder may be decoupled from FIR samples through an FIR RAM, thus resulting in a less complex design and shorter processing times. In some embodiments, an intermediate memory may be used when passing information between the SOVA and LDPC of the iterative decoder. In some embodiments, the SOVA-required information may be continuously serialized from information received from the LDPC during each LDPC iteration. In some embodiments, the 1/(1+D2) precoder of the HR RLL encoder may be split into two serial, 1/(1+D) precoders. One 1/(1+D) precoder may be pulled outside of the HR RLL encoder and used in conjunction with the iterative decoder. A 1/(1+D) precoder may be used with the iterative decoder while maintaining the RLL constraints imposed upon the encoded information by the HR RLL encoder.

Abstract: A memory controller includes an encoder, a modulator, and a demodulator. A nonvolatile memory includes memory cells, each programmable to one of three or more levels. According to first encoded data, the modulator programs a first subset of the memory cells to a first of the levels and a second subset of the memory cells to a second of the levels. Measurable values of the first subset are characterized by a first probability density function having a first width. Measurable values of the second subset are characterized by a second probability density function having a second width. The first width is greater than the second width. The encoder generates the first encoded data based on input data such that the first subset is smaller than the second subset. The demodulator is configured to output second encoded data in response to measurable values of the memory cells.

Abstract: Methods, apparatuses, and systems for comparing threshold voltages of a plurality of flash memory cells to a plurality of reference voltages. A number of flash memory cells having threshold voltages that fall within each bin of a plurality of bins is determined. The plurality of bins each represent a plurality of threshold voltage ranges. A threshold voltage distribution of the plurality of flash memory cells is calculated based at least in part on the number of flash memory cells that fall into each of the bins.

Abstract: Systems and methods are provided for recovering data stored in memory. A group of data is encoded using a first layer of code to form a first encoded group of data. Individual portions of the first encoded group of data are then encoded using a second layer of code to form a second encoded group of data. A processor may request access to an individual portion of the group of data. The encoded version of the requested individual portion is retrieved from memory and decoded using the second layer of code to recover the requested individual portion. If the recovery of the requested individual portion fails, the remaining encoded portions of the group are retrieved from memory and decoded using the first layer of code to recover the requested individual portion.

Abstract: A system including a write module to write pilot data at predetermined locations in a page of memory cells that are interspersed with user data in the page. The pilot data has a first predetermined pattern and provides an indication of a disturbance experienced by the user data due to noise and a read, write, or erase operation performed on the page. A read module reads data from the predetermined locations subsequent to writing the pilot data. A signal processing module compares the data read from the predetermined locations with the pilot data and estimates, based on the comparison of the data read from the predetermined locations in the page with the pilot data, and the first predetermined pattern of the pilot data, the disturbance experienced by the user data due to the noise and the read, write, or erase operation performed on the page.

Abstract: A system comprising a memory, and a control module external to the memory. The memory includes a plurality of cells. The control module is configured to receive user data to be stored in the plurality of cells, select one of a plurality of sequences of pilot data, based on the selected one of the plurality of sequences of pilot data, generate pilot data having a known predetermined sequence, combine the pilot data with the user data, and output the combined pilot data and user data. A write module is configured to write the combined pilot data and user data to the plurality of cells of the memory.

Abstract: A storage drive includes a first integrated circuit, a second integrated circuit, an interface, an encoder, and a write module. The first integrated circuit includes a first array of memory cells. The second integrated circuit includes a second array of memory cells. The interface is connected to a host. The interface is configured to receive a first block of data transmitted from the host to the storage drive. The encoder is configured to encode the first block of data. The write module is configured to write (i) a first portion of the encoded first block of data to a first row of the first array of memory cells, and (ii) a second portion of the encoded first block of data to a first row of the second array of memory cells.

Abstract: A system for identifying and compensating for non-linear transition shift in a magnetic medium data storage device is disclosed. The non-linear transition shift compensation system includes a non-linear transition shift estimation module adapted to generate non-linear transition shift estimates for specific bit patterns. The system further includes a pre-compensation module adapted to adjust the temporal spacing of binary transitions written to the magnetic medium based on the non-linear transition shift estimates generated by the non-linear transition shift estimation module for specific bit patterns corresponding to bit patterns appearing in the data being written to the magnetic medium.