Non-volatile read refresh operation comprising discharging a plurality of word lines

Abstract

A memory system includes: a nonvolatile memory device including a plurality of memory blocks each including a plurality of memory cells coupled to a plurality of word lines; and a controller configured to control the nonvolatile memory device to perform a read operation on the plurality of memory blocks, wherein the read operation includes: a first operation of supplying a first voltage level to the plurality of word lines, a second operation of discharging the plurality of word lines to a second voltage level, a third operation of supplying a third voltage level less than the first voltage level to the plurality of word lines, and a fourth operation of discharging the plurality of word lines to a fourth voltage level.