SEMICONDUCTOR INTEGRATED CIRCUIT DEVICE

摘要

PROBLEM TO BE SOLVED: To realize a high-integrated and high-speed nonvolatile memory stably operating a phase change memory in a short operation cycle time. SOLUTION: A latch is provided in a write driver WD, and the resistance of a phase change element is made higher with a write enable signal in each column cycle and made lower simultaneously inactivation of a precharge signal after input of a precharge command. Consequently, the time of writing to the memory cell in which the phase change resistance is made higher and the period from writing operation in which the phase change resistance is made higher to readout operation of the memory cell can be made long to make the writing operation stable. COPYRIGHT: (C)2005,JPO&NCIPI