Patent ID: 11972791
Assignee: SAMSUNG ELECTRONICS CO., LTD.
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 0:
1. A method of reading data in a nonvolatile memory device including a plurality of memory cells having a plurality of states including a first state and a second state, the method comprising:
performing a first read operation for the first state; and
performing a second read operation for the second state,
wherein performing the first read operation includes:
obtaining cell counts for the first state by performing a valley cell count operation for the first state, the cell counts comprising a first cell count of a first region where the first state overlaps the second state in a plot characterizing a number of on-cells of the first state and a number of on-cells of the second state against threshold voltage;
determining a first read voltage level for the first state based on the first cell count and at least one first reference parameter for the first state; and
performing a first sensing operation for the first state by using the first read voltage level, and

wherein performing the second read operation includes:
determining a second read voltage level for the second state and at least one second reference parameter for the second state; and
performing a second sensing operation for the second state by using the second read voltage level.