Abstract: A method for data storage in a memory that includes a plurality of analog memory cells includes estimating respective achievable storage capacities of the analog memory cells. The memory cells are assigned respective storage configurations defining quantities of data to be stored in the memory cells based on the estimated achievable capacities. The data is stored in the memory cells in accordance with the respective assigned storage configurations. The achievable storage capacities of the analog memory cells are re-estimated after the memory has been installed in a host system and used for storing the data in the host system. The storage configurations are modified responsively to the re-estimated achievable capacities.

Abstract: A method for data storage includes, in a host system that operates alternately in a normal state and a hibernation state, reserving a hibernation storage space in a non-volatile storage device for storage of hibernation-related information in preparation for entering the hibernation state. While the host system is operating in the normal state, a storage task other than storage of the hibernation-related information is performed using at least a portion of the reserved hibernation storage space.

Abstract: A method for data storage includes storing first data bits in a set of multi-bit analog memory cells at a first time by programming the memory cells to assume respective first programming levels. Second data bits are stored in the set of memory cells at a second time that is later than the first time by programming the memory cells to assume respective second programming levels that depend on the first programming levels and on the second data bits. A storage strategy is selected responsively to a difference between the first and second times. The storage strategy is applied to at least one group of the data bits, selected from among the first data bits and the second data bits.

Abstract: A method for data storage includes storing data in a memory that includes one or more memory units, each memory unit including memory blocks. The stored data is compacted by copying at least a portion of the data from a first memory block to a second memory block, and subsequently erasing the first memory block. Upon detecting a failure in the second memory block after copying the portion of the data and before erasure of the first memory block, the portion of the data is recovered by reading the portion from the first memory block.

Abstract: A method for data storage includes storing data in a target analog memory cell, which is one of a group of analog memory cells that are connected in series with one another, by writing a storage value into the target memory cell. The storage value written into the target memory cell is verified while biasing the other memory cells in the group with respective first pass voltages. After writing and verifying the storage value, the storage value is read from the target memory cell while biasing the other memory cells in the group with respective second pass voltages, wherein at least one of the second pass voltages applied to one of the other memory cells in the group is lower than a respective first pass voltage applied to the one of the other memory cells. The data is reconstructed responsively to the read storage value.

Abstract: A method for data storage includes accepting data for storage in a memory including multiple analog memory cells. For each memory cell, a respective set of nominal analog values is assigned for representing data values to be stored in the memory cell, by choosing the nominal analog values for a given memory cell in a respective range that depends on interference between the given memory cell and at least one other memory cell in the memory. The data is stored in each memory cell using the respective selected set of the nominal analog values.

Abstract: A method for data storage in a memory including multiple memory cells arranged in blocks, includes storing first and second pages in respective first and second groups of the memory cells within a given block of the memory. A pattern of respective positions of one or more defective memory cells is identified in the first group. The second page is recovered by applying the pattern identified in the first group to the second group of the memory cells.

Abstract: A method for data storage includes, in a memory that includes multiple memory blocks, specifying at a first time a first over-provisioning overhead, and storing data in the memory while retaining in the memory blocks memory areas, which do not hold valid data and whose aggregated size is at least commensurate with the specified first over-provisioning overhead. Portions of the data from one or more previously-programmed memory blocks containing one or more of the retained memory areas are compacted. At a second time subsequent to the first time, a second over-provisioning overhead, different from the first over-provisioning overhead, is specified, and data storage and data portion compaction is continued while complying with the second over-provisioning overhead.

Abstract: A method for data storage includes setting a group of analog memory cells to respective analog values by performing an iterative process that applies a sequence of pulses to the memory cells in the group. During the iterative process, a progress of the iterative process is assessed, and a parameter of the iterative process is modified responsively to the assessed progress. The iterative process is continued in accordance with the modified parameter.

Abstract: A method for data storage includes accepting data for storage in a memory that includes multiple analog memory cells and supports a set of built-in programming commands. Each of the programming commands programs a respective page, selected from a group of N pages, in a subset of the memory cells. The subset of the memory cells is programmed to store M pages of the data, M>N, by performing a sequence of the programming commands drawn only from the set.

Abstract: A method for operating a memory (28) includes storing data in a group of analog memory cells (32) of the memory as respective first voltage levels. After storing the data, second voltage levels are read from the respective analog memory cells. The second voltage levels are affected by cross-coupling interference causing the second voltage levels to differ from the respective first voltage levels. Cross-coupling coefficients, which quantify the cross-coupling interference among the analog memory cells, are estimated by processing the second voltage levels. The data stored in the group of analog memory cells is reconstructed from the read second voltage levels using the estimated cross-coupling coefficients.

Abstract: A method for data storage in a memory that includes multiple analog memory cells fabricated using respective physical media, includes identifying a group of the memory cells whose physical media have deteriorated over time below a given storage quality level. A rejuvenation process, which causes the physical media of the memory cells in the group to meet the given storage quality level, is applied to the identified group. Data is stored in the rejuvenated group of the memory cells.

Abstract: A method for data storage includes accepting data for storage in a memory including multiple analog memory cells. For each memory cell, a respective set of nominal analog values is assigned for representing data values to be stored in the memory cell, by choosing the nominal analog values for a given memory cell in a respective range that depends on interference between the given memory cell and at least one other memory cell in the memory. The data is stored in each memory cell using the respective selected set of the nominal analog values.

Abstract: A method for data storage in a memory including multiple memory cells arranged in blocks, includes storing first and second pages in respective first and second groups of the memory cells within a given block of the memory. A pattern of respective positions of one or more defective memory cells is identified in the first group. The second page is recovered by applying the pattern identified in the first group to the second group of the memory cells.

Abstract: A method for data storage includes storing data in a target analog memory cell, which is one of a group of analog memory cells that are connected in series with one another, by writing a storage value into the target memory cell. The storage value written into the target memory cell is verified while biasing the other memory cells in the group with respective first pass voltages. After writing and verifying the storage value, the storage value is read from the target memory cell while biasing the other memory cells in the group with respective second pass voltages, wherein at least one of the second pass voltages applied to one of the other memory cells in the group is lower than a respective first pass voltage applied to the one of the other memory cells. The data is reconstructed responsively to the read storage value.

Abstract: A method for data storage includes, in a memory that includes at least N memory units, each memory unit including memory blocks, defining superblocks, each superblock including a respective set of N of the memory blocks that are allocated respectively in N different ones of the memory units, such that compaction of all the memory blocks in a given superblock is performed without any intervening programming operation in the given superblock. Data is stored in the memory by computing redundancy information for a selected portion of the data, and storing the selected portion and the redundancy information in the N memory blocks of a selected superblock.

Abstract: A method for operating a memory (28) includes storing data in a group of analog memory cells (32) of the memory as respective first voltage levels. After storing the data, second voltage levels are read from the respective analog memory cells. The second voltage levels are affected by cross-coupling interference causing the second voltage levels to differ from the respective first voltage levels. Cross-coupling coefficients, which quantify the cross-coupling interference among the analog memory cells, are estimated by processing the second voltage levels. The data stored in the group of analog memory cells is reconstructed from the read second voltage levels using the estimated cross-coupling coefficients.

Abstract: A method for data storage includes encoding each of multiple data items individually using a first Error Correction Code (ECC) to produce respective encoded data items. The encoded data items are stored in a memory. The multiple data items are encoded jointly using a second ECC, so as to produce a code word of the second ECC, and only a part of the code word is stored in the memory. The stored encoded data items are recalled from the memory and the first ECC is decoded in order to reconstruct the data items. Upon a failure to reconstruct a given data item from a respective given encoded data item by decoding the first ECC, the given data item is reconstructed based on the part of the code word of the second ECC and on the encoded data items other than the given encoded data item.

Abstract: A method for data storage includes, in a memory that includes multiple memory blocks, specifying at a first time a first over-provisioning overhead, and storing data in the memory while retaining in the memory blocks memory areas, which do not hold valid data and whose aggregated size is at least commensurate with the specified first over-provisioning overhead. Portions of the data from one or more previously-programmed memory blocks containing one or more of the retained memory areas are compacted. At a second time subsequent to the first time, a second over-provisioning overhead, different from the first over-provisioning overhead, is specified, and data storage and data portion compaction is continued while complying with the second over-provisioning overhead.

Abstract: A method for operating a memory (28) that includes a plurality of analog memory cells (32) includes storing data in the memory by writing first storage values to the cells. Second storage values are read from the cells, and a Cumulative Distribution Function (CDF) of the second storage values is estimated. The estimated CDF is processed so as to compute one or more thresholds. A memory access operation is performed on the cells using the one or more thresholds.