Abstract: A method for data storage includes, in a first programming phase, storing first data in a group of analog memory cells by programming the memory cells in the group to a set of initial programming levels. In a second programming phase that is subsequent to the first programming phase, second data is stored in the group by: identifying the memory cells in the group that were programmed in the first programming phase to respective levels in a predefined partial subset of the initial programming levels; and programming only the identified memory cells with the second data, so as to set at least some of the identified memory cells to one or more additional programming levels that are different from the initial programming levels.

Abstract: A method for data storage includes storing data in analog memory cells by programming the memory cells with respective analog input values. After storing the data, respective analog output values are read from the memory cells using multiple read thresholds, which define multiple ranges of the analog output values. Respective numbers of read errors in the data, corresponding to the analog output values falling in the ranges, are assessed. The stored data is recovered based on respective numbers of the read errors assessed in the ranges.

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 includes dividing a group of analog memory cells into multiple subsets. The memory cells in the group are sensed simultaneously by performing a single sense operation, while applying to the subsets of the memory cells respective different sets of read thresholds, so as to produce respective readout results. An optimal set of the read thresholds is estimated by processing the multiple readout results obtained from the respective subsets using the different sets of the read thresholds.

Abstract: A method for data storage includes providing at least first and second readout schemes for reading storage values from a group of analog memory cells that are connected to respective bit lines. The first readout scheme reads the storage values using a first bit line charging configuration having a first sense time, and the second readout scheme reads the storage values using a second bit line charging configuration having a second sense time, shorter than the first sense time. A condition is evaluated with respect to a read operation that is to be performed over a group of the memory cells. One of the first and second readout schemes is selected responsively to the evaluated condition. The storage values are read from the group of the memory cells using the selected readout scheme.

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, in a first programming phase, storing first data in a group of analog memory cells by programming the memory cells in the group to a set of initial programming levels. In a second programming phase that is subsequent to the first programming phase, second data is stored in the group by: identifying the memory cells in the group that were programmed in the first programming phase to respective levels in a predefined partial subset of the initial programming levels; and programming only the identified memory cells with the second data, so as to set at least some of the identified memory cells to one or more additional programming levels that are different from the initial programming levels.

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 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 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.

Abstract: A method for data storage includes initially storing a sequence of data pages in a memory that includes multiple memory arrays, such that successive data pages in the sequence are stored in alternation in a first number of the memory arrays. The initially-stored data pages are rearranged in the memory so as to store the successive data pages in the sequence in a second number of the memory arrays, which is less than the first number. The rearranged data pages are read from the second number of the memory arrays.

Abstract: A method for data storage includes accepting data for storage in a memory that includes multiple analog memory cells. The data is stored in a first group of the memory cells by programming a second group of the memory cells so as to cause the second group to generate interference in the first group, and individually erasing the first group while verifying that analog levels of the memory cells in the first group subject to the interference are within a predefined bound following erasure. After erasing the first group, the first group of the memory cells is programmed with the data.

Abstract: A method for data storage includes storing data in a group of analog memory cells by writing into the memory cells in the group respective storage values, which program each of the analog memory cells to a respective programming state selected from a predefined set of programming states, including at least first and second programming states, which are applied respectively to first and second subsets of the memory cells, whereby the storage values held in the memory cells in the first and second subsets are distributed in accordance with respective first and second distributions. A first median of the first distribution is estimated, and a read threshold, which differentiates between the first and second programming states, is calculated based on the estimated first median. The data is retrieved from the analog memory cells in the group by reading the storage values using the calculated read threshold.

Abstract: A method for data storage includes initially storing a sequence of data pages in a memory that includes multiple memory arrays, such that successive data pages in the sequence are stored in alternation in a first number of the memory arrays. The initially-stored data pages are rearranged in the memory so as to store the successive data pages in the sequence in a second number of the memory arrays, which is less than the first number. The rearranged data pages are read from the second number of the memory arrays.

Abstract: A method for data storage includes predefining an order of programming a plurality of analog memory cells that are arranged in rows. The order specifies that for a given row having neighboring rows on first and second sides, the memory cells in the given row are programmed only while the memory cells in the neighboring rows on at least one of the sides are in an erased state, and that the memory cells in the given row are programmed to assume a highest programming level, which corresponds to a largest analog value among the programming levels of the cells, only after programming all the memory cells in the given row to assume the programming levels other than the highest level. Data is stored in the memory cells by programming the memory cells in accordance with the predefined order.

Abstract: A method for data storage includes providing at least first and second readout configurations for reading storage values from analog memory cells, such that the first readout configuration reads the storage values with a first sense time and the second readout configuration reads the storage values with a second sense time, shorter than the first sense time. A condition is evaluated with respect to a read operation that is to be performed over a group of the memory cells. One of the first and second readout configurations is selected responsively to the evaluated condition. The storage values are read from the group of the memory cells using the selected readout configuration.

Abstract: A method for data readout includes sending to a memory device, which includes a plurality of analog memory cells, a request to read a requested memory page that is stored in a first group of the memory cells. A programming status of a second group of the memory cells is reported to the memory device, so as to cause the memory device to select a reading configuration responsively to the reported programming status and to read the requested memory page from the first group of the memory cells using the selected reading configuration. The requested memory page is received from the memory device.

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.

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 providing at least first and second readout configurations for reading storage values from analog memory cells, such that the first readout configuration reads the storage values with a first sense time and the second readout configuration reads the storage values with a second sense time, shorter than the first sense time. A condition is evaluated with respect to a read operation that is to be performed over a group of the memory cells. One of the first and second readout configurations is selected responsively to the evaluated condition. The storage values are read from the group of the memory cells using the selected readout configuration.