| 摘要 |
<P>PROBLEM TO BE SOLVED: To control unauthorized access to data in a microcontroller, when the operation of microcontroller deviates from a specific operation condition within a guaranteed operation range and the performance thereof is degraded. <P>SOLUTION: A data processing circuit has a controller (147) that controls, a rewritable nonvolatile memory (146), a nonvolatile memory and an external interface. Also, the circuit employs a first detector (152) for detecting whether the operation of the data processing circuit deviates from a first operation condition, and a second detector (154) for detecting whether operation of the data processing circuit deviates from a second operation condition that is severer than the first operation condition. The circuit instructs "reset" to the controller when the first detector detects the deviation of operation from the first operation condition. The controller backs up an internal state based on the fact that the second detector detects the deviation from the second operation condition, and also restricts access from the outside to a storage area of the nonvolatile memory. <P>COPYRIGHT: (C)2009,JPO&INPIT |
