| 摘要 |
<p>A microcomputer having a data EEPROM and a program EEPROM, in which a predetermined lock code is written a the specific area, comprising a lock-code-decoding circuit that is connected with the data EEPROM, reads out the concerned lock code, and decodes the code; a logic circuit that performs a predetermined operation on a mode bit that was serially input from the outside, by the output of the lock-code-decoding circuit; and a mode-bit-decoding circuit that decodes the processed mode bit by receiving the output of the logic circuit, and sends the result to functional blocks, is provided; and thereby the falsification of the data of money and the program written in a nonvolatile memory can be prevented.</p> |
