Patent Number: 7,613,038

Title: Semiconductor integrated circuit device

Abstract: There is achieved a high-integrated and high-speed nonvolatile memory which can stabilize an operation of a phase-change memory for a short operation cycle time. A latch is provided in a write driver. A change to a high-resistance state of a phase-change element is performed per column cycle by a write-enable signal, and a change to a low-resistance state thereof is performed after a pre-charge command is inputted and concurrently with deactivation of a pre-charge signal. Thereby, a write time to a memory cell in which phase-change resistance is changed to a low-resistance state, and a period from a write operation for changing the phase-change resistance to a high-resistance state to a read operation to the above memory cell can be lengthened without extending the column cycle time, so that the stable write operation is achieved.

Inventors: Takemura; Riichiro (Tokyo, JP), Sakata; Takeshi (Hino, JP), Takaura; Norikatsu (Tokyo, JP), Kajigaya; Kazuhiko (Iruma, JP)

Assignee: Hitachi, Ltd.

International Classification: G11C 7/00 (20060101)

Expiration Date: 1/03/02017