Nonvolatile semiconductor memory device and method of controlling the same

摘要

A control circuit, on selecting a memory cell as a selected memory cell to perform a write operation, before executing the write operation, applies a first voltage to the selected memory cell via a first line and a second line to perform a first read operation. The control circuit, when judged that a result of the first read operation does not match write data intended to be written, executes the write operation. The control circuit, when judged that a result of the first read operation matches write data intended to be written, omits a voltage application operation for the write operation.;The first voltage is larger than a second voltage which is applied to the selected memory cell via the first line and the second line in a second read operation, the second read operation acting as a normal read operation for reading held data of the memory cell.

主权项

1. A nonvolatile semiconductor memory device, comprising:
a memory cell array configured having memory cells arranged therein, the memory cells being disposed at intersections of a plurality of first lines and a plurality of second lines, the plurality of second lines being disposed to intersect the first lines, and the memory cells each including a variable resistance element; and a control circuit operative to control the memory cell array, the control circuit being configured to, in the case of selecting the memory cell as a selected memory cell to perform a write operation, before executing the write operation, apply a first voltage to the selected memory cell via the first line and the second line to perform a first read operation, when it is judged that a result of the first read operation does not match write data intended to be written by the write operation, execute the write operation, and when it is judged that a result of the first read operation matches write data intended to be written by the write operation, omit a voltage application operation for the write operation, and the first voltage being larger than a second voltage which is applied to the selected memory cell via the first line and the second line in a second read operation, the second read operation acting as a normal read operation for reading held data of the memory cell.