Storage device related to performing a read operation and method of operating the storage device

Abstract

A memory device including a plurality of memory cells, a peripheral circuit, and a control logic. The peripheral circuit performs a first read operation using a plurality of read voltages on selected memory cells. The control logic controls the peripheral circuit to perform a cell counting operation, adjust remaining read voltages among the plurality of read voltages based on a read offset table and a cell count which is a result of the cell counting operation, and perform a first read operation on the selected memory cell with the remaining read voltages, in the first read operation. The control logic performs a read data output operation of a second read operation performed before the first read operation and the cell counting operation corresponding to the first read operation in parallel among a plurality of successively performed read operations.