公开(公告)号：US20230298672A1

公开(公告)日：2023-09-21

申请号：US17899293

申请日：2022-08-30

Applicant: KIOXIA CORPORATION

Inventor： Katsuyuki SHIMADA ,  Yuki KOMATSU ,  Shingo YANAGAWA ,  Yasuyuki USHIJIMA

IPC: G11C16/26 ,  G11C16/34 ,  G11C29/52

CPC classification number: G11C16/26 ,  G11C16/3404 ,  G11C29/52

Abstract: According to one embodiment, 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.

公开(公告)号：US20240055065A1

公开(公告)日：2024-02-15

申请号：US18230151

申请日：2023-08-03

Applicant: Kioxia Corporation

Inventor： Ryo YAMAKI ,  Masanobu SHIRAKAWA ,  Naomi TAKEDA ,  Takashi NAKAGAWA ,  Shingo YANAGAWA

IPC: G11C29/12

CPC classification number: G11C29/12005 ,  G11C2029/1202

Abstract: According to one embodiment, a memory system includes a non-volatile first memory with first storage areas. A controller executes a first read operation on a second storage area of the first storage areas. When an error correction in the first read operation fails, the controller acquires a first measured value being a value of a read voltage for suppressing the number of occurrences of error bits in the second storage area. The controller updates, on the basis of the first measured value, one of first candidate values of the read voltage with a second candidate value. When the error correction in a second read operation for a third storage area of the first storage areas fails, the controller executes the read operation once or more on the third storage area by using, as the read voltages, different first candidate values of the first candidate values.