Kioxia Corporation

Yasuyuki Ushijima

Yasuhiko Kurosawa

Yuki Komatsu

Shinichi Kanno

Masanobu Shirakawa

Naomi Takeda

Katsuyuki Shimada

Hisaki Niikura

Hanan Weingarten

Avi Steiner

Eyal Nitzan

Shingo Yanagawa

Kyoka Konishi

Eriko Akaihata

Liran Kost

Alex Britva

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

According to one embodiment, each time the number of program/erase cycles of a block increases by a first number of times, a controller of a memory system measures the number of error bits of data read from a plurality of memory cells connected to each of a plurality of word lines. The controller identifies a word line group including a word line corresponding to the number of error bits which is greater than a threshold. The controller selects, based on an average number of error bits of the identified word line group, a parameter set to be applied to the identified word line group from a plurality of parameter sets. The controller changes, to the selected parameter set, a parameter set defining a program operation for the identified word line group.

Memory system controlling nonvolatile memory

A memory system includes a memory including nonvolatile memory cells, and a controller configured to set read voltages for reading data stored in the nonvolatile memory cells. The controller stores first shift patterns relating to a plurality of read voltages, first index information associating to a first shift pattern with each of a plurality of memory cell groups, second shift patterns relating to differences between read voltages and read voltages set according to a first shift pattern, and second index information associating a second shift pattern with each memory cell group. The controller generates read voltages of a target memory cell group based on the first shift pattern voltages and the second shift pattern voltages.

Memory system and read method

A memory system includes non-volatile memory cells for storing multiple bit data and a controller configured to control to apply read voltages to the non-volatile memory cells at different threshold levels to read data written to the non-volatile memory cells. The non-volatile memory cells comprise different sub-groups. The controller stores first information indicating a first initial value for each of the different threshold level of the read voltages, second information that indicates whether data can be successfully read from each sub-group when the respective different threshold levels of the read voltages are set to the first initial values, and third information that indicates a second initial value for each different threshold level of the read voltages for at least one sub-group for which data reading was unsuccessful when a read voltage was set to the first initial value.

According to one embodiment, a memory system includes a nonvolatile memory and a memory controller configured to execute a patrol process, in response to a first command set from a host device. In the patrol process, the memory controller is configured to read first data from the nonvolatile memory, and not to output the first data to the host device.

Memory system and information processing system

According to one embodiment, a memory system includes a memory device and a controller. The controller is configured to instruct to apply, to a first word line, a determination voltage that is based on a first value and a first difference value in a case where it is determined whether or not a first data value has been written in a first memory cell, to instruct to apply, to a second word line, a determination voltage that is based on the first value, the first difference value, and a second difference value in a case where it is determined whether or not the first data value has been written in the second memory cell, and to change the first difference value in a case where a first condition is satisfied.

Growing community of inventors

Yokohama, Japan

Yasuyuki Ushijima