Abstract: A decoder performs iterative decoding of a codeword encoded by a binary symmetry-invariant product code, such as a half product code or quarter product code. In response to the iterative decoding reaching a stopping set, the decoder determines by reference to an ambient error graph formed from the stopping set whether or not the stopping set is correctable by post-processing. If not, the decoder outputs the uncorrected codeword and signals a decoding failure. In response to determining that the stopping set is correctable by post-processing, the decoder inverts all bits of the codeword corresponding to edges of the ambient error graph, applies an additional round of iterative decoding to the codeword to obtain a corrected codeword, and outputs the corrected codeword. Post-processing in this manner substantially lowers an error floor associated with the binary symmetry-invariant product code.

Abstract: A device for determining an actual cell state of a resistive memory cell having a plurality M of programmable cell states comprising a sensing circuit, a settling circuit, a prebiasing circuit, and a resistor coupled in parallel to the resistive memory cell, wherein the resistor is configured to reduce an effective resistance seen by the prebiasing circuit. The sensing circuit is configured to sense a sensing voltage of the resistive memory cell and output a resultant value in response to the sensing voltage which is indicative for the actual cell state. The settling circuit is configured to settle the sensing voltage to a certain target voltage representing one of the M programmable cell states. The prebiasing circuit is configured to prebiase a bitline capacitance of the resistive memory cell such the sensing voltage is close to the certain target voltage.

Abstract: A computer program product according to one embodiment includes a computer readable storage medium having program instructions embodied therewith. The program instructions are executable by a processing circuit to cause the circuitry to perform a method including determining, after writing data to a non-volatile memory block, one or more delta threshold voltage shift (TVS?) values. One or more overall threshold voltage shift values for the data written to the non-volatile memory block are calculated, the values being a function of the one or more TVS? values to be used when writing data to the non-volatile memory block. The overall threshold voltage shift values are stored. A base threshold voltage shift (TVSBASE) value, the one or more TVS? values, or both the TVSBASE value and the one or more TVS? values are re-calibrated during a background health check after a predetermined number of background health checks without calibration are performed.

Abstract: In one embodiment, a computer program product includes a computer readable storage medium having program instructions embodied therewith. The program instructions are executable by a processing circuit to cause the processing circuit to perform a method that includes determining, after writing data to a non-volatile memory block, one or more delta threshold voltage shift (TVS?) values. One or more overall threshold voltage shift values is calculated for the data written to the non-volatile memory block. The one or more overall threshold voltage shift values are stored. The method also includes reading one or more TVS values from a non-volatile controller memory, and resetting a program/erase cycle count since last calibration after calibrating the one or more overall threshold voltage shift values. The one or more TVS? values and the program/erase cycle count since last calibration are stored to the non-volatile controller memory.

Abstract: A device for storing data in a plurality of multi-level cell memory chips. The device includes a scrambling unit to generate a plurality of candidate scrambled sequences of data by performing a plurality of scrambling operations on a sequence of data to be stored, a calculation unit to calculate a cost function for each of the plurality of candidate scrambled sequences of data, the result of each cost function being indicative of a balancing degree of subsequences of a candidate scrambled sequence, when the subsequences of the candidate scrambled sequence are written to the plurality of multi-level cell memory chips, a selection unit to select one of the candidate scrambled sequences of data based on the results of the cost functions, and a storing unit to store the selected candidate scrambled sequence of data in the multi-level cell memory chips by storing the subsequences across the multi-level memory chips.

Abstract: In one embodiment, a computer-implemented method includes determining, by a processor, after the writing of data to a non-volatile memory block, one or more delta threshold voltage shift (TVS?) values configured to track temporary changes with respect to changes in the underlying threshold voltage distributions due to retention and/or read disturb errors. One or more overall threshold voltage shift values is calculated for the data written to the non-volatile memory block, the one or more overall threshold voltage shift values being a function of the one or more TVS? values to be used when writing data to the non-volatile memory block. The one or more overall threshold voltage shift values are stored.

Abstract: A computer-implemented method for performing a voltage-based measurement of a resistive memory cell having a plurality of programmable cell states includes providing, via a processor, a prebiased voltage at a connecting node. The method further includes prebiasing a bitline capacitance of the resistive memory cell. In other aspects, the method includes settling, via the processor, a sensing circuit to a target voltage. The method further includes outputting a resultant value based on a sensed voltage at the resistive memory cell.

Abstract: In at least one embodiment, a history data structure of a Lempel-Ziv compressor is preloaded with fixed predetermined history data typical of actual data of a workload of the Lempel-Ziv compressor. The Lempel-Ziv compressor then compresses each of multiple data pages in a sequence of data pages by reference to the fixed predetermined history data.

Abstract: A sensing circuit senses a sensing voltage of a resistive memory cell and outputs a resultant value in response to the sensing voltage which is indicative for the actual cell state. A settling circuit includes a plurality of current mirrors for settling the sensing voltage to a certain target voltage representing one of M programmable cell states. A prebiasing circuit is provided for prebiasing a bitline capacitance of the resistive memory cell such that the sensing voltage is close to the certain target voltage. A resistance circuit includes a plurality of resistors connected in series and coupled in parallel to the resistive memory cell. The resistance circuit is configured to reduce an effective resistance seen by the prebiasing circuit. The settling circuit and the resistance circuit are configured to form a plurality of current-resistor pairs switchable to define a linear range detection currents corresponding to the certain target voltages.

Abstract: A computer-implemented method, according to one embodiment, includes: repeating the following sequence at least until a page stripe of a memory cache has at least a predetermined amount of data stored therein: finding an open codeword having an amount of available space which is greater than or equal to a size of a compressed logical page, and storing the compressed logical page in the open codeword having the amount of available space which is greater than or equal to a size of the compressed logical page. Other systems, methods, and computer program products are described in additional embodiments.

Abstract: In a data storage system, a prior set S of prefix codes for pseudo-dynamic compression as well as data compressed utilizing prior set S are stored. While data compressed utilizing prior set S are stored in the data storage system, the number of prefix codes utilized by the data storage system for pseudo-dynamic compression are augmented. Augmenting the number of codes includes determining a new set S? of prefix codes for pseudo-dynamic compression from a training data set selected from a workload of the data storage system and storing the new set S? in the data storage system with the prior set S.

Abstract: A computer-implemented method, according to one embodiment, includes: repeating the following sequence at least until a page stripe of a memory cache has at least a predetermined amount of data stored therein: finding an open codeword having an amount of available space which is greater than or equal to a size of a compressed logical page, and storing the compressed logical page in the open codeword having the amount of available space which is greater than or equal to a size of the compressed logical page. Other systems, methods, and computer program products are described in additional embodiments.

Abstract: Methods and apparatus 3 are provided for encoding data for storage in multilevel memory cells 2 having q cell-levels. Input data words are encoded into respective codewords, each having N symbols with one of q symbol-values, via an encoding scheme adapted such that the q symbol-values have unequal multiplicities within at least some codewords, and the multiplicity of each of the q symbol-values in every codeword is no less than ?, where ??2 and more preferably ?3. A first type of encoding scheme uses recursive symbol-flipping to enforce the ?-constraint, adding indicator symbols to indicate the flipped symbols. A second type of encoding scheme maps data words to codewords of a union of permutation codes, the initial vectors for these permutation codes being selected to enforce the ?-constraint. The N qary symbols of each codeword are supplied for storage in respective cells of the multilevel memory 2.

Abstract: A method for encoding an input data block for storage in q-level cells of solid-state memory includes producing a preliminary block from the input data block by modulation encoding at least part of the input block into a first group of qary symbols via a first drift-tolerant encoding scheme, the preliminary block comprising the first group of qary symbols and any remainder of the input block not encoded via the first encoding scheme; generating parity data for the preliminary block via an error-correction encoding scheme; modulation encoding the parity data and any remainder of the input block into a second group of qary symbols via a second drift-tolerant encoding scheme; and supplying the qary symbols of the first and second groups for storage in respective q-level memory cells.

Abstract: A method, according to one embodiment, includes repeating the following sequence at least until a page stripe of a memory cache has at least a predetermined amount of data stored therein: receiving a compressed logical page of data, finding an open codeword having an amount of available space which is greater than or equal to a size of the compressed logical page, and storing the compressed logical page in the open codeword having the amount of available space which is greater than or equal to a size of the compressed logical page. The compressed logical page does not straddle out of the open codeword. Other systems, methods, and computer program products are described in additional embodiments.

Abstract: In one embodiment, an apparatus includes one or more memory devices, each memory device having non-volatile memory configured to store data, and a memory controller connected to the one or more memory devices, the memory controller being configured to receive data to be stored to the one or more memory devices, store read-hot data within one error correction code (ECC) codeword as aligned data, and store read-cold data to straddle two or more ECC codewords as non-aligned data and/or dispersed data. According to another embodiment, a method for storing data to non-volatile memory includes receiving data to store to one or more memory devices, each memory device including non-volatile memory configured to store data, storing read-hot data within one ECC codeword as aligned data, and storing read-cold data to straddle two or more ECC codewords as non-aligned data and/or dispersed data.

Abstract: A device for storing data in a plurality of multi-level cell memory chips. The device includes a scrambling unit to generate a plurality of candidate scrambled sequences of data by performing a plurality of scrambling operations on a sequence of data to be stored, a calculation unit to calculate a cost function for each of the plurality of candidate scrambled sequences of data, the result of each cost function being indicative of a balancing degree of subsequences of a candidate scrambled sequence, when the subsequences of the candidate scrambled sequence are written to the plurality of multi-level cell memory chips, a selection unit to select one of the candidate scrambled sequences of data based on the results of the cost functions, and a storing unit to store the selected candidate scrambled sequence of data in the multi-level cell memory chips by storing the subsequences across the multi-level memory chips.

Abstract: A quarter product code codeword includes various R code symbols and C code symbols each including a plurality of symbols. Each symbol is loaded into a diagonal anti-diagonal structure in two unique locations. To provide for fast loading, the symbols may be shifted by one or more shift registers associated with the diagonal or anti-diagonal structure. The two locations at which each symbol is positioned are included within different diagonals or anti-diagonals making it possible to load or unload either symbol or multiple symbols in a single clock cycle. Further, by partitioning the diagonal anti-diagonal structure, multiple respective symbols or plurality of symbols may be loaded or unloaded in a single clock cycle.

Abstract: A memory system for storing data in a plurality N of memory chips. The memory system includes a number K of sets of memory chips, wherein each set of the K sets includes a number M of the memory chips, with N=K·M; and one signal processing unit having a number L of signal processing engines for signal processing data of the N memory chips and having a data link interface for interfacing each of the K sets.

Abstract: A device for storing data in a plurality of multi-level cell memory chips. The device includes a scrambling unit to generate a plurality of candidate scrambled sequences of data by performing a plurality of scrambling operations on a sequence of data to be stored, a calculation unit to calculate a cost function for each of the plurality of candidate scrambled sequences of data, the result of each cost function being indicative of a balancing degree of subsequences of a candidate scrambled sequence, when the subsequences of the candidate scrambled sequence are written to the plurality of multi-level cell memory chips, a selection unit to select one of the candidate scrambled sequences of data based on the results of the cost functions, and a storing unit to store the selected candidate scrambled sequence of data in the multi-level cell memory chips by storing the subsequences across the multi-level memory chips.