Abstract: A system including a reference voltage module to select a first reference voltage between a first threshold voltage corresponding to a first state of a memory cell and a second threshold voltage corresponding to a second state of the memory cell, a second reference voltage less than the first reference voltage, and a third reference voltage greater than the first reference voltage. The system includes a read module to perform a first read operation to determine a state of the memory cell based on the first reference voltage, and in response to a first failure to decode data read from the memory cell in the first read operation, perform a second read operation to determine the state based on the second reference voltage and a third read operation to determine the state based on the third reference voltage.

Abstract: A memory integrated circuit (IC) includes a read module and a sequence detector module. The read module reads S memory cells (cells) located along one of a bit line and a word line and generates S read signals, where S is an integer greater than 1. The sequence detector module detects a data sequence based on the S read signals and reference signals. The data sequence includes data stored in the S cells. Each of the reference signals includes an interference-free signal associated with one of the S cells and an interference signal associated with another of the S cells that is adjacent to the one of the S 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: A system and method are provided to detect defects in a data storage medium by sampling data read from the data storage medium. Time referenced samples of data read from the data storage medium are equalized to mediate the effects of channel noise and the equalized samples are decoded by a decoder, such as a Viterbi decoder. The decoded signal is then reconstructed through a reconstruction filter to approximate the equalized signal. The equalized data signal and the reconstructed data signal are then combined and compared in a bit-by-bit deconstruction scheme to determine, based on a variation between the signal elements, that a defect exists on the data storage medium. Additional action is then taken to mediate the effects of attempting to process corrupted data based on the defect by isolating the defective bit.

Abstract: The present disclosure includes apparatus, systems and techniques relating to lossless data compression. In some implementations, an apparatus includes a memory module to store data. The memory module includes a first buffer portion to store encoded symbols of the data, and a second buffer portion to store symbols of the data to be encoded. The apparatus includes an encoder to compare the symbols stored in the second buffer portion with the encoded symbols stored in the first buffer portion and to compress the data. The encoder can operate in a first encoding mode to encode the symbols in the second buffer portion with corresponding codewords until detecting a repeated pattern of symbols in the second buffer portion that matches the encoded symbols in the first buffer portion. The encoder can operate in a second encoding mode responsive to detecting the repeated pattern.

Abstract: In an implementation, a media drive includes bit patterned magnetic media and a module. The module is to cause data encoded by one or more error correction codes to be written on the bit patterned magnetic media with a constraint that is configured to be used to synchronize the data if a bit insertion or deletion occurs.

Abstract: In an implementation, a media drive comprises bit patterned magnetic media and one or more modules. The one or more modules are to cause data to be written on the bit patterned magnetic media in a data sector that includes a synchronization mark disposed between data blocks of the data sector.

Abstract: Systems and methods for processing and decoding TCM/BCM-coded signal vectors. A multi-dimensional signal vector is received by, for example, a TCM or BCM decoder. The TCM/BCM decoder identifies the closest signal points in the signal constellation set, or “nearest neighbors,” for each dimension of the received signal vector. The TCM/BCM decoder then forms a test set that includes a plurality of multi-dimensional test vectors, where each dimension of each test vector is based on an identified nearest neighbor. In particular, each test point in the test set is based on a different combination of the nearest neighbors. The TCM/BCM decoder can compute branch metrics based on only the test points in the test set, and can make detection decisions using the computed branch metrics.

Abstract: A method and system for error correction decoding uses concatenated error correction decoders. A channel decoder receives encoded user data from a transmission channel, decodes the bits of the user data, and generates erasure information for the decoded bits. The decoded bits and erasure information is received by an outer ECC decoder, which first performs erasure decoding. If the erasure decoding is successful, then the decoded user data is output. If the erasure decoding is not successful, then the outer ECC decoder performs the more complex error decoding. Thus, error decoding need not be performed for user data that can be successfully decoded using erasure decoding. The extra operations required to perform error decoding is avoided. In this manner, the complexity of the overall decoding process is reduced, significantly reducing the computation power required, while maintaining the desired performance level.

Abstract: The present disclosure includes systems and techniques relating to non-volatile memory. The systems and techniques can include accessing a threshold value that is associated with a data area of a non-volatile memory structure, performing a comparison using the threshold value and a first value associated with the data area, and selectively reprogramming data of the data area based on the comparison. A programming operation on the data area can trigger a reset of the first value. Accessing a threshold value can include accessing a second value that reflects a count of programming operations on the data area or a time between programmings and using the second value to select the threshold value.

Abstract: A memory integrated circuit (IC) includes an input that receives data for programming a target cell to a state. The memory IC further includes a programming module that determines a programming value for programming the target cell to the state based on the state and states of C cells that are adjacent to the target cell. The target cell and the C cells each store K bits per cell, where C and K are integers greater than or equal to 1.

Abstract: The present disclosure includes apparatus, systems and techniques relating to detecting sync marks. In some implementations, an apparatus includes phase locking circuitry that includes a phase calculator to identify a phase of sampled data, and a phase-locked loop to generate an output signal and phase-lock the generated output signal with the calculated phase of the sampled data to produce a phase-locked signal. The apparatus includes detector circuitry to receive phase information of the phase-locked output signal. The detector circuitry includes a detector to generate a stream of decision bits for the sampled data with each bit in the stream being associated with a different phase. The detector circuitry includes an output selector to select at least one bit from the stream based on the received phase information of the phase-locked output signal.

Abstract: A memory system including a read module, a demultiplexer, an acquisition module, a tracking module and a control module. The read module is configured to (i) read pilot data and user data stored in a block of a first memory and (ii) generate read signals based on the pilot data and the user data. The demultiplexer is configured to, based on the read signals, generate pilot signals and user data signals. The acquisition module is configured to (i) receive the pilot signals and (ii) generate a first estimate of a signal-to-noise ratio of the block of the first memory based on a predetermined pilot pattern. The tracking module is configured to generate a second estimate of the signal-to-noise ratio of the block of the first memory based on the user data signals. The control module is configured to generate recovered data based on the first estimate and the second estimate.

Abstract: An apparatus including: a plurality of multi-level memory cells configured to store data, wherein one or more of the multi-level memory cells are designated as pilot memory cells, and wherein each pilot memory cell is configured to store known, pre-determined data; an estimation block configured to, based on the known, pre-determined data, determine (i) estimated mean values of level distributions of the multi-level memory cells and (ii) estimated standard deviation values of level distributions of the multi-level memory cells; and a computation block configured to compute at least optimal or near optimal detection threshold values of level distributions of the multi-level memory cells based, at least in part, on (i) the estimated mean values and (ii) the estimated standard deviation values, wherein the optimal or near optimal detection threshold values are to be used in order to facilitate reading of the data stored in the multi-level memory cells.

Abstract: Systems, apparatuses, and methods for encoding and decoding using generalized concatenated codes (GCC) are described. The methods include receiving data; encoding the received data to obtain first encoded data; encoding the first encoded data until a GCC encoding reaches an intermediate level; and terminating the GCC encoding at the intermediate level.

Abstract: Disclosed herein are systems and methods for detecting a signal to provide a detected data sequence, comprising providing a plurality of candidate data sequences, computing baseline wander estimates associated with respective ones of the candidate data sequences, comparing a signal to each of the respective ones of the candidate data sequences, wherein the comparisons are compensated by corresponding ones of the baseline wander estimates, and choosing, based on the comparisons, one of the plurality of candidate data sequences to be the detected data sequence.

Abstract: Systems, methods, and other embodiments associated with soft decoding for a quantized channel are described. According to one embodiment, an apparatus includes a soft decoder configured to decode a signal received from a quantized channel based, at least in part, on one or more log likelihood ratios (LLRs). The apparatus may also include a reliability memory configured to store one or more known LLRs, and a controller configured to repetitively and selectively provide the soft decoder with known LLRs chosen from the reliability memory, to control the soft decoder to decode the signal, and to selectively update the reliability memory upon determining that the soft decoder successfully decoded the signal.

Abstract: Apparatuses and methods are provided for adaptively updating a target for a recording channel, such as a magnetic recording channel. In some embodiments, a read channel apparatus is provided which includes data path modules and adaptive path modules. The data path modules estimate user information from a recording channel, and the adaptive path modules adaptively update the target taps of the recording channel. The adaptive path modules may use a linearly constrained least-mean square (LC-LMS) algorithm to determine the amount and direction of each tap update, where the linear constraint may be a maximum phase or a mixed phase constraint. The adaptive path modules may operate independently of and be decoupled from the data path modules.

Abstract: Adaptive memory read and write systems and methods are described herein that adapts to changes to threshold voltage distributions of memory cells as of result of, for example, the detrimental affects of repeated cycling operations of the memory cells. The novel systems may include at least multi-level memory cells, which may be multi-level flash memory cells, and a computation block operatively coupled to the multi-level memory cells. The computation block may be configured to compute optimal or near optimal mean and detection threshold values based, at least in part, on estimated mean and standard deviation values of level distributions of the multi-level memory cells. The optimal or near optimal mean and detection threshold values computed by the computation block may be subsequently used to facilitate writing and reading, respectively, of data to and from the multi-level memory cells.

Abstract: Embodiments of the present invention provide channel estimation for multi-level memories using pilot signals. A memory apparatus includes a memory block comprising a plurality of memory cells and adapted to operate with at least two levels of signals for writing data into and reading data from the memory cells. At least two memory cells are employed as reference cells to output a plurality of pilot signals. The memory apparatus also includes a channel block operatively coupled to the memory block, and adapted to facilitate the writing and reading of data into and from the memory cells. The channel block is also adapted to receive the pilot signals and determine one or more disturbance parameters based at least in part on the pilot signals and to compensate the read back signals based at least in part on the determined one or more disturbance parameters during said reading of data from the memory cells. Other embodiments may be described and claimed.