摘要:
Methods and apparatus are provided for programming multiple program values per signal level in flash memories. A flash memory device having a plurality of program values is programmed by programming the flash memory device for a given signal level, wherein the programming step comprises a programming phase and a plurality of verify phases. In another variation, a flash memory device having a plurality of program values is programmed, and the programming step comprises a programming phase and a plurality of verify phases, wherein at least one signal level comprises a plurality of the program values. The signal levels or the program values (or both) can be represented using one or more of a voltage, a current and a resistance.
摘要:
Methods and apparatus are provided for write-side intercell interference mitigation in flash memories. A flash memory device is written by obtaining program data to be written to at least one target cell in the flash memory; obtaining one or more bits of program data for at least one aggressor cell to be programmed later than the target cell: and precompensating for intercell interference for the target cell by generating precompensated program values. The aggressor cells comprise one or more cells adjacent to the target cell, such as adjacent cells in a same wordline as the target cell and/or cells in an upper or lower adjacent wordline to the target cell. The precompensated program values for the target cell are optionally provided to the flash memory.
摘要:
Various embodiments of the present invention provide systems and methods for data processing. As an example, a data processing circuit is disclosed that includes a data detector circuit. The data detector circuit includes an anti-causal noise predictive filter circuit and a data detection circuit. In some cases, the anti-causal noise predictive filter circuit is operable to apply noise predictive filtering to a detector input to yield a filtered output, and the data detection circuit is operable to apply a data detection algorithm to the filtered output derived from the anti-causal noise predictive filter circuit.
摘要:
Methods and apparatus for soft data generation for memory devices using decoder performance feedback. At least one soft data value is generated in a memory device, by obtaining performance feedback from a decoder; obtaining an error statistic based on the performance feedback; and generating the at least one soft data value based on the obtained error statistic. The performance feedback comprises one or more of decoded bits, a number of erroneous bits based on data decoded by the decoder and a number of unsatisfied parity checks.
摘要:
Methods and apparatus are provided for intercell interference mitigation using modulation coding. During programming of a flash memory, a modulation encoding is performed that selects one or more levels for programming the flash memory such that a reduced number of cells in the flash memory are programmed with a value that violates one or more predefined criteria. During a reading of a flash memory, a modulation decoding is performed that assigns one or more levels to cells in the flash memory such that a reduced number of cells in the flash memory are read with a value that violates one or more predefined criteria. The predefined criteria can be based, for example, on one or more of an amount of disturbance caused by the programmed cell; a voltage shift of a programmed cell: a voltage stored by a programmed cell; an amount of change in current through a programmed cell; and an amount of current through a programmed cell.
摘要:
Embodiments of the invention include a method and apparatus for encoding data and a system for transmitting and/or storing data, in which the data is encoded and precoded in a manner that does not violate previously established data constraints, such as modulation encoding constraints. The method includes the steps of modulation encoding the data using a modulation code defined by at least one modulation constraint, parity encoding the modulation encoded information, and preceding the encoded information. The preceding step either partially precodes information bits and precodes parity bits, precodes information bits but not parity bits, or precodes both information bits and parity bits in such a manner that does not violate modulation constraints. Also, the parity encoding step can be performed in such a manner that does not violate modulation code constraints.
摘要:
Methods and apparatus are provided for soft data generation for memory devices using reference cells. At least one soft data value is generated in a memory device by writing a known data to one or more reference cells; reading one or more of the reference cells; obtaining a read statistic based on the read one or more reference cells; and obtaining the at least one soft data value based on the obtained read statistic. The read statistics can optionally be obtained for one or more desired locations of a memory array; or for a given pattern, PATT, in one or more aggressor cells. The read statistic can optionally comprise asymmetric statistics obtained for a plurality of possible values.
摘要:
Methods and apparatus are provided for intercell interference mitigation using modulation coding. During programming of a flash memory, a modulation encoding is performed that selects one or more levels for programming the flash memory such that a reduced number of cells in the flash memory are programmed with a value that violates one or more predefined criteria. During a reading of a flash memory, a modulation decoding is performed that assigns one or more levels to cells in the flash memory such that a reduced number of cells in the flash memory are read with a value that violates one or more predefined criteria. The predefined criteria can be based, for example, on one or more of an amount of disturbance caused by the programmed cell; a voltage shift of a programmed cell: a voltage stored by a programmed cell; an amount of change in current through a programmed cell; and an amount of current through a programmed cell.