| 摘要 |
<p>PURPOSE:To prevent the reading of the entire program and data in a built-in ROM even under a memory expansion mode. CONSTITUTION:This microcomputer is provided with a built-in ROM consecutive reference detection circuit 12 detecting whether or not the consecutive reference for a built-in flash EEPROM 3 by the only instruction of the same program counter value based on a program counter value from a program counter 10, an instruction code from an instruction register 11, and an internal address bus 5 in a CPU 2. When the built-in ROM consecutive reference detection circuit 12 detects more than the prescribed number of consecutive reference for the built-in ROM, it outputs a signal actuating this to a deletion circuit 13 of the built-in flash EEPROM 3, and deletes the contents of the built-in flash EEPROM 3 by the deletion circuit 13.</p> |
