| 摘要 |
<p>PURPOSE:To provide the microcomputer which enables PROM data to be read out even after security is imposed without lowering the protection effect of the security. CONSTITUTION:In the microcontroller which has an electrically rewritable read-only memory (PROM) and a security (data read inhibiting) circuit mounted on the same semiconductor substrate, the security circuit is equipped with a key code storage means 1 which stores a key code, a key code input means 2 which inputs a key code from a program, and a comparator 3 which compares the key code inputted from the key code input means 2 with the key code stored in the key code input means 2 and resets the security when they match each other.</p> |
