| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve such a problem that since a current being smaller than a rewriting current is made to flow within a range in which a phase state of a phase transition element is not varied at the time of read-out, read-out speed is reduced. <P>SOLUTION: The apparatus has a memory cell storing information by varying a state of a crystal by applied temperature, and an input/output circuit, read-out information is rewritten at the time of read-operation. Also, at the time of write-operation, read out information is replaced by write-in information from the outside, and replaced information is written in the memory cell. Further, a cell is current-driven by the same circuit in read-out and write-in. Further, a pulse is applied between read-out and rewriting or write-in. Further, polarity of the applied pulse is different. Further, word line voltage is made higher than power source voltage at the time of write-in operation. When it is non-selection, the word line voltage is made lower than a ground potential. Then, read-out speed can be made high. <P>COPYRIGHT: (C)2007,JPO&INPIT |
