公开(公告)号：US09704571B2

公开(公告)日：2017-07-11

申请号：US15209126

申请日：2016-07-13

Applicant: SAMSUNG ELECTRONICS CO., LTD.

Inventor： Do-Kyun Kim ,  Dong-Yang Lee ,  Kwang-Hyun Kim

IPC: G11C11/24 ,  G11C11/56 ,  G11C11/4096 ,  G11C11/4094 ,  G11C11/4091

CPC classification number: G11C11/565 ,  G11C7/1006 ,  G11C11/4091 ,  G11C11/4094 ,  G11C11/4096

Abstract: A method of operating a memory device includes writing cell data having one of at least three states to a memory cell; amplifying a voltage level of a bit line connected to the memory cell; determining that the cell data is in a first state when the voltage level of the bit line sensed at a sensing point is equal to or greater than a first reference voltage; determining that the cell data is in a second state when the voltage level of the bit line sensed at the sensing point is equal to or less than a second reference voltage which has a lower voltage level than the first reference voltage; and determining that the cell data is in a third state when the cell data is not in the first or second states.