Kioxia Corporation

Eyal Nitzan

Avi Steiner

Hanan Weingarten

Yasuhiko Kurosawa

Kenji Sakurada

Yasuyuki Ushijima

Liran Kost

Alex Britva

A method for reading data from a solid-state drive (SSD) configured to store data in a plurality of memory cells arranged in memory blocks comprising rows, the method performed by a controller in communication with the plurality of memory cells. The method comprises retrieving data from a target row of memory cells of the plurality of memory cells associated with a read request received from a host using initial threshold voltages. The method also includes decoding the data using a hard decision stage. Additionally the method comprises estimating read threshold voltages of the target row of memory cells based on a transformation of a distribution of threshold voltages of cells in a memory block containing the target row when the hard decision decoding stage fails. The method further includes retrieving data from the target row using the estimated read threshold voltages.

Feature based read threshold estimation in NAND flash memory

One or more processors of a system may determine one or more program parameters of a plurality of rows of cells of a non-volatile memory, determine a first threshold of a first parameter of each row based on the one or more program parameters of the plurality of rows, determine, by changing a programming time of each row, a set of parameters of each row that causes the first parameter not to cross the first threshold, determine a second threshold of a second parameter of each row based on production statistics of a plurality of dies as a result of mass production, adjust the programming time of each row to cause the second parameter not to cross the second threshold, and program data to a first row of the plurality of rows using the set of parameters of the first row and the adjusted programming time of the first row.

System and method for determining optimal program parameters in non-volatile memory systems

A method for reading data from an SSD, comprising: retrieving data from a target row of memory cells using initial threshold voltages; decoding the data using a first hard decision decoding stage; estimating a bit error rate (BER) of a target row of memory cells based on a distribution of threshold voltages of cells in a memory block containing the target row when the first hard decision decoding stage fails; classifying the BER of the target row based on a first BER threshold (BER-TH1); and executing a first read flow comprising at least one hard decision decoding stage if the BER is less than the BER-TH1, and executing a second read flow similar to the first read flow if the BER is greater than or equal to the BER-TH1, the second read flow skipping a hard decision decoding stage of the first read flow.

Bit error rate estimation and classification in NAND flash memory

Systems, methods, non-transitory computer-readable media for dynamically estimating interference compensation thresholds for read operations in non-volatile memory devices, including determining a plurality of interference states with respect to an interference source of a target row of a non-volatile memory to be read, determining compensation shifts for the plurality of interference states by determining a compensation shift for each of two or more interference states of the plurality of interference states, and applying the compensation shifts for the plurality of interference states to reading the target row.

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Tel Aviv, Israel

Eyal Nitzan