Abstract: A system for storing a plurality of logical pages in a set of at least one flash device, each flash device including a set of at least one erase block, the system comprising apparatus for distributing at least one of the plurality of logical pages over substantially all of the erase blocks in substantially all of the flash devices, thereby to define, for at least one logical page, a sequence of pagelets thereof together including all information on the logical page and each being stored within a different erase block in the set of erase blocks; and apparatus for reading each individual page from among the plurality of logical pages including apparatus for calling and ordering the sequence of pagelets from different erase blocks in the set of erase blocks.

Abstract: A flash memory system comprising temporary memory, writing apparatus for writing first logical data from the temporary memory into flash memory cells having at least two levels, thereby to generate a physical representation of the first logical data including known errors, reading apparatus for reading the physical representation from the cells, thereby to generate, and store in the temporary memory, second logical data which if read immediately is identical to the first logical data other than the known errors; and controlling apparatus controlling the writing apparatus and the reading apparatus and including known error ID apparatus operative to identify the known errors by comparing the first logical data to second logical data read immediately after the physical representation is generated, to store information characterizing the known errors and to use the information, when the second logical data is next read, to correct the known errors.

Abstract: Apparatus and methods for operating a flash device characterized by use of Lee distance based codes in a flash device so as to increase the number of errors that can be corrected for a given number of redundancy cells, compared with Hamming distance based codes.

Abstract: Flash memory apparatus including a plurality of memory portions, and a controller operative to reserve for data retention purposes, for at least a first duration of time, only certain portions from among said plurality of memory portions including allocating data, during the first duration of time, only to the certain portions, thereby to define at least one of the plurality of memory portions other than the certain portions as a retired memory portion for the first duration of time.

Abstract: A system and method for soft decoding data. A plurality of candidate error corrections may be generated to correct one or more data bits having soft bit information. Each candidate error correction may define suggested changes to the data bits and is associated with a soft bit value. The soft bit values associated the plurality of candidate error corrections may be mapped to a uniform scale, for example, a uniform finite or integer grid. The plurality of candidate error corrections may be ordered to have combined associated mapped values in a monotonically non-decreasing order. One or more of the plurality of candidate error corrections may be soft decoded in the order of the associated mapped values by a decoding operation for each candidate error correction therein with the associated non-mapped soft bit values.

Abstract: A method for decoding a plurality of flash memory cells which are error-correction-coded as a unit, the method comprising providing a hard-decoding success indication indicating whether or not hard-decoding is at least likely to be successful; and soft-decoding the plurality of flash memory cells at a first resolution only if the hard-decoding success indication indicates that the hard-decoding is not at least likely to be successful.

Abstract: A system and a method for reprogramming a non volatile memory (NVM) portion, the method includes: receiving an initial content of an NVM portion; wherein the initial content differs from an erase content of the NVM portion; processing the previously programmed content in response to input content that should be represented by an initial content of the NVM portion; wherein the processing is characterized by a write limitation that prevents a non-erase value of a bit to be changed to an erase value; wherein the processing comprises at least one out of skip value based encoding, generating error correction information and error correction code based encoding; and writing the processed content of the NVM portion to the NVM portion.

Abstract: A method, computer readable medium storing instructions and system for managing flash memory. Data sector are received and each is written into a data block of a buffer of a non-volatile memory device. Pointers in a data management structure are created for each data sector corresponding to an associated logical block and a storage location of the data sector in the buffer. When a predefined criterion is fulfilled before the buffer becomes full, a number of logical blocks to be merged is determined and data sectors corresponding to the number of logical blocks to be merged are written from the buffer to a primary non-volatile data storage memory of the non-volatile memory device.

Abstract: A method and system for writing in flash memory, the system operative for, and the method comprising, writing data onto a plurality of logical pages characterized by a plurality of different probabilities of error respectively, the writing including encoding data intended for each of the plurality of physical pages using a redundancy code with a different code rate for each individual physical page, the code rate corresponding to the probability of error in the individual logical page.

Abstract: A method for determining thresholds useful for converting cell physical levels into cell logical values in an array of digital memory cells storing physical levels which diminish over time, the method comprising determining extent of deterioration of the physical levels and determining thresholds accordingly for at least an individual cell in said array; and reading the individual cell including reading a physical level in the cell and converting the physical level into a logical value using the thresholds, wherein the determining comprises storing predefined physical levels rather than data-determined physical levels in each of a plurality of cells and computing extent of deterioration by determining deterioration of the predefined physical levels.

Abstract: A flash memory module and a method for programming a page of flash memory cells, the method includes: receiving a cycle count indication indicative of a number of program cycles of the page of memory cells; setting a value of a programming parameter of a programming operation based on the cycle count indication; and programming at least one flash memory cell of the page of flash memory cells by performing the programming operation.

Abstract: Chien search apparatus operative to evaluate an error locator polynomial having a known rank and including a sequence of terms for each element in a finite field whose elements correspond respectively to bits in each of a stream of data blocks to be decoded, the apparatus comprising a sequence of functional units each operative to compute a corresponding term in the sequence of terms included in the error locator polynomial, each term having a degree; and a power saving unit operative to de-activate at least one individual functional unit from among the sequence of functional units, the individual functional unit being operative, when active, to compute a term whose degree exceeds the rank.

Abstract: A flash memory controller, a computer readable medium and a method for generating reliability information using a hard information interface, the method may include performing multiple read attempts, while using the hard information interface, of a plurality of flash memory cells to provide multiple read results; wherein each flash memory cell is read by providing a reference voltage to the flash memory cell; wherein a same reference voltage is provided during the multiple read attempts; and generating, for each flash memory cell, reliability information based upon multiple read results of the flash memory cell.

Abstract: A system, a non-transitory computer readable medium and a method for wear estimation of a flash memory device, the method may include: programming information to a first portion of the flash memory device during a test programming process; measuring a duration of the test programming process; and estimating a wear characteristic of the first portion of the flash memory device thereby providing an estimated wear characteristic, wherein the estimating is responsive to the duration of the test programming process.

Abstract: A system, a method and non-transitory computer readable medium storing instructions for interleaving at least two portions of a first codeword of the group between at least two flash memory planes while violating at least one ordering rule out of (a) an even odd ordering rule, (b) a programming type ordering rule, and (c) a codeword portions ordering rule and interleaving different portions of other codewords of the group between multiple flash memory planes while maintaining the even odd ordering rule, the programming type ordering rule and the codeword portions ordering rule.

Abstract: Systems, computer readable media and methods for updating a flash memory device involve procedures for transferring, from a flash memory device to an external controller, only a portion of a data entity; and determining, by the external controller, based upon the portion of the data entity, whether to complete a copy back operation of the data entity or to correct errors of the data entity. If it is determined to correct errors of the data entity, then the procedure includes (a) completing a transfer of the data entity to the external controller; (b) error correcting the data entity to provide an amended data entity; and (c) writing the amended data entity to the flash memory device. If, however, it is determined to complete the copy back operation then the procedures includes completing the copy back operation of the data entity by transferring the data entity within the flash memory device.

Abstract: A system for storing a plurality of logical pages in a set of at least one flash device, each flash device including a set of at least one erase block, the system comprising apparatus for distributing at least one of the plurality of logical pages over substantially all of the erase blocks in substantially all of the flash devices, thereby to define, for at least one logical page, a sequence of pagelets thereof together including all information on the logical page and each being stored within a different erase block in the set of erase blocks; and apparatus for reading each individual page from among the plurality of logical pages including apparatus for calling and ordering the sequence of pagelets from different erase blocks in the set of erase blocks.

Abstract: A system and method for unbiased rounding away from, or toward, zero comprising apparatus for truncating N bits from an original M bit input number thereby to provide a M?N bit number, and apparatus for adding the equivalent value of ‘½’ to the M?N bit number unless the input number is negative, or positive, respectively, and the N truncated bits represent exactly ½.