Marvell Asia Pte., Ltd.

Nirmal V Shende

Nedeljko Varnica

Mats Oberg

A memory device includes a plurality of memory cells. Each memory cell stores a plurality of signal levels representing a plurality of values corresponding to a respective plurality of bits, bits in corresponding respective positions of significance across the plurality of memory cells constituting respective memory pages of the memory device. The memory device also includes decoding circuitry to decode each bit value of one of the respective memory pages using bit values read from at least one other one of the respective memory pages, adjacent to the one of the respective memory pages. The plurality of signal levels may represent the plurality of values according to a Gray code. The decoding circuitry may be configured to compare each signal level to a set of voltage thresholds, and to decode a subset of the plurality of signal levels using fewer than all voltage thresholds in the set of voltage thresholds.

Adjacent-page-assisted memory decoder and method

A method of reading data read from a NAND Flash memory device includes decoding a set of data read from the device, using an initial set of hard bit thresholds, when the decoding is unsuccessful, performing a read-retry operation that retries the decoding using, in order, each of a plurality of entries in a read-retry table of hard bit thresholds, stopping when decoding based on one of the entries is successful, and when the read-retry operation is unsuccessful, performing a deep retry operation using a set of log-likelihood ratios (LLRs) that vary in at least one of values or symmetries. NAND Flash memory apparatus includes a Flash media controller, a data bus, and an adaptive LLR engine configured to generate, for use in a deep retry operation, a set of LLRs that, and to transfer the set of LLRs that vary to the media controller via the bus.

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Manteca, CA, United States of America

Nirmal V Shende