摘要:
k information bits are encoded according to a code with which is associated a parity check matrix H that has n columns. The entire resulting codeword is stored in a storage medium. At least n′
摘要:
A method of storing and reading data, using a memory that includes a plurality of cells (e.g. flash cells), such that data are stored in the cells by setting respective values of a physical parameter of the cells (e.g. threshold voltage) to be indicative of the data, and such that data are read from the cells by measuring those values. One of the cells and its neighbors are read. The data stored in the cell are estimated, based on the measurements and on respective extents to which the neighbors disturb the reading. Preferably, the method also includes determining those respective extents to which the neighbors disturb the reading, for example based on the measurements themselves.
摘要:
Embodiments described herein disclose methods, devices, and media for storing data. Methods including the steps of: receiving data to be stored in a memory that includes at least three blocks, wherein each block, for storing the data, has at least one metadata value, associated with each block, that is dependent upon a writing time of each block; grouping at least three blocks into at least two block groups, wherein at least one block group contains at least two blocks; associating a respective metadata value with each block group; and associating the respective metadata value of a respective block group with each block storing the data contained in the respective block group, without storing a dedicated copy of at least one metadata value for each block. In some embodiments, at least one metadata value is stored in a block-group table.
摘要:
A plurality of logical pages is stored in a MBC flash memory along with corresponding ECC bits, with at least one of the MBC cells storing bits from more than one logical page, and with at least one of the ECC bits applying to two or more of the logical pages. When the pages are read from the memory, the data bits as read are corrected using the ECC bits as read. Alternatively, a joint, systematic or non-systematic ECC codeword is computed for two or more of the logical pages and is stored instead of those logical pages. When the joint codeword is read, the logical bits are recovered from the codeword as read. The scope of the invention also includes corresponding memory devices, the controllers of such memory devices, and also computer-readable storage media bearing computer-readable code for implementing the methods.
摘要:
Each of a plurality of flash memory cells is programmed to a respective one of L≧2 threshold voltage states within a threshold voltage window. A histogram is constructed by determining how many of some or all of the cells have threshold voltages in each of two or more of m≧2 threshold voltage intervals within the threshold voltage window. Reference voltages for reading the cells are selected based on estimated values of shape parameters of the histogram. Alternatively, the cells are read relative to reference voltages that define m≧2 threshold voltage intervals that span the threshold voltage window, to determine numbers of at least a portion of the cells whose threshold voltages are in each of two or more of the threshold voltage intervals. Respective threshold voltage states are assigned to the cells based on the numbers without re-reading the cells.
摘要:
To store a plurality of input bits, the bits are mapped to a corresponding programmed state of one or more memory cells and the cell(s) is/are programmed to that corresponding programmed state. The mapping may be many-to-one or may be an “into” generalized Gray mapping. The cell(s) is/are read to provide a read state value that is transformed into a plurality of output bits, for example by maximum likelihood decoding or by mapping the read state value into a plurality of soft bits and then decoding the soft bits.
摘要:
A plurality of logical pages is stored in a MBC flash memory along with corresponding ECC bits, with at least one of the MBC cells storing bits from more than one logical page, and with at least one of the ECC bits applying to two or more of the logical pages. When the pages are read from the memory, the data bits as read are corrected using the ECC bits as read. Alternatively, a joint, systematic or non-systematic ECC codeword is computed for two or more of the logical pages and is stored instead of those logical pages. When the joint codeword is read, the logical bits are recovered from the codeword as read. The scope of the invention also includes corresponding memory devices, the controllers of such memory devices, and also computer-readable storage media bearing computer-readable code for implementing the methods.
摘要:
A method and system for optimizing flash memory without dedicated parity area and with reduced array size. The memory size of a multi level cell (MLC) flash is reduced and controller operation is simplified. Simplified operation includes the controller being able to program each host data page to an integer number of flash pages. A maximal available information bits per cell (IBPC) is maintained in a flash device while also maximizing the programming throughput of the flash. Features include the ability to dynamically select which number of cell states is used by flash memory cells.
摘要:
To store, successively, in a plurality of memory cells, first and second pluralities of input bits that are equal in number, a first transformation transforms the first input bits into a first plurality of transformed bits. A first portion of the cells is programmed to store the first transformed bits according to a mapping of bit sequences to cell levels, but, if the first transformation has a variable output length, only if there are few enough first transformed bits to fit in the first cell portion. Then, without erasing a second cell portion that includes the first portion, if respective levels of the cells of the second portion, that represent a second plurality of transformed bits obtained by a second transformation of the second input bits, according to the mapping, are accessible from the current cell levels, the second portion is so programmed to store the second transformed bits.
摘要:
A data storage device and methods of performing memory operations using location-based parameters are disclosed. A method includes identifying a set of parameter values associated with a physical block of a memory array on a memory die. The set of parameter values is identified based on a physical location of the physical block. A physical location may include an edge or a central region of the memory array or the memory die. The memory die may comprise a nonvolatile semiconductor memory (e.g., flash memory). Parameter values may include a size or a number of programming steps, pulse widths, maximum programming or erase voltages, reading or verify reference voltages, and parameters relating to error correction, among others, including time dependent parameters. A memory access operation, such as a reading, programming, or erasing operation, is initiated with respect to the physical block in accordance with the set of parameter values.