Nonvolatile semiconductor storage device and method for operating same

Abstract

A nonvolatile semiconductor memory device for suppressing a current consumption caused by a transient current because of the potential change of the bit and word lines at the time of shifting between the programming, reading, and erasing actions in a highly integrated memory cell array is provided. A memory cell () array comprises two-terminal memory cells each having a variable resistance element whose resistance value reversibly changes by pulse application are arranged in a row and column directions, wherein the memory cells in a row are connected at one end to common word lines (WLto WLn), the memory cells in a column are connected at the other end to common bit lines (BLto BLm), and a common unselected voltage V/2 is applied to both unselected word and bit lines not connected to the selected memory cell during the reading, programming, and erasing actions for the selected memory cell.