Patent ID: 9431122
Filing Date: 2016-08-30
CPC Classification: G11C

Claim Text:
1. An operating method of a storage device which includes a nonvolatile memory and a memory controller configured to control the nonvolatile memory, the nonvolatile memory comprising a plurality of cell strings arranged on a substrate, each of the cell string including a ground selection transistor, a plurality of memory cells and a string selection transistor sequentially stacked on the substrate, the operating method comprising: receiving a read command and a read address; performing a read operation about memory cells of the nonvolatile memory, selected by the read address, according to the read command; performing a reliability verification read operation about unselected memory cells of the nonvolatile memory which are not the selected memory cells; and calculating a difference between a count value and a reference count value, including counting a number of memory cells, each corresponding to at least one state of an erase state and program states of the unselected memory cells, to define the count value based on a result of the reliability verification read operation; and outputting data read with the read operation to an external device and not outputting data read with the reliability verification read operation to the external device.