Nonvolatile semiconductor memory device and write/verify method thereof

Abstract

A nonvolatile semiconductor memory device includes write/verify circuits, a switching elements which divides the bit lines into plural portions, and a control circuit. The control circuit is configured to control the write/verify circuits and switching elements. The control circuit performs a control operation to perform the write and verify operations with the switching elements set in an OFF state when a memory cell of an address to be written lies on the write/verify circuit side in the memory cell array, write and save data into a memory cell lying on the write/verify circuit side with the switching elements set in the OFF state when the memory cell lies farther apart from the write/verify circuit than the switching elements, and then turn ON the switching elements while the write/verify circuit is not being operated and write the saved data into a memory cell of an address to be written.