| 摘要 |
PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor memory device capable of storing multivalue information while suppressing reading errors, and its driving method. SOLUTION: During reading processing, a processing step of applying a first writing voltage to a variable resistance element of a first resistance state under a predetermined application condition, and applying a reading voltage to detect a resistance state is repeatedly executed until the detection of transition to a second resistance state while keeping the same application condition of the first writing voltage or changing at least one of an application time and an applied voltage. By specifying the application condition of a second writing voltage applied to be changed to the first resistance state before the start of the processing step based on the application condition of the first writing voltage applied before first detection of the second resistance state, writing information associated with the application condition of the second writing voltage is read. COPYRIGHT: (C)2009,JPO&INPIT |
