Patent ID: 11881265
Assignee: KIOXIA CORPORATION
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 0:
1. A memory system, comprising:
a non-volatile memory with memory cells for storing multiple bit data; and
a controller configured to apply read voltages to the non-volatile memory at different threshold levels to read data written to the memory cells, wherein
the non-volatile memory comprises sub-groups of memory cells each sub-group including a plurality of memory cells, and
the controller is configured to store:
first information indicating a first initial value for each 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.