| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To efficiently use a nonvolatile memory device to dispense with mixing a high-withstand voltage device, and to shorten its development period. <P>SOLUTION: The semiconductor memory device includes: an external writing terminal 15; an internal writing/rewriting circuit 17; a first nonvolatile memory device 11 on which data are written using an external writing/rewriting device 3 through the external writing terminal 15 and which holds the data; and the second nonvolatile memory device 21 on which data are written/rewritten by the internal writing/rewriting circuit 17. The first and second nonvolatile memory devices 11, 21 are made into the same device structure. The first and second nonvolatile memory devices 11, 21 are constituted by different memory areas in a single nonvolatile memory device, in which the boundary of the memory areas may also be made variable. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
