| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To improve the security of the information stored in a nonvolatile memory sealed in a semiconductor element chip. <P>SOLUTION: A chip 12 provided with the nonvolatile memory and a chip 13 for making the chip 12 normally operate are provided, and a control signal for controlling the nonvolatile memory to be mounted on the chip 12 is inputted to the chip 12 through the chip 13. The chips 12 and 13 are respectively provided with an inverter circuit for inverting the polarity of an optional control signal among a plurality of control signals inputted from an external circuit. Only when the control signal is inputted to the nonvolatile memory through both inverter circuits of the chips 12 and 13, the control signal becomes a normal signal to the nonvolatile memory. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
