| 摘要 |
<p>In ECU (2) for controlling an engine, a microcomputer (8) executes a program in a mask ROM (21) after releasing the reset, determines a signal (MS) of a specific input terminal, and switches in accordance with the foregoing determination result the self operation mode into either one of the normal mode to execute a control program in a flash ROM (20) and the rewrite mode to update and write a data from an external unit (14) into the ROM (20). A monitor circuit (26) monitors a watchdog pulse (WP) from the microcomputer (8), outputs a reset pulse (RP) to the microcomputer (8) when determining an abnormality, and alters the level of the foregoing signal (MS) to the microcomputer (8) into the level of the normal mode into the level of the rewrite mode. <IMAGE></p> |
