| 摘要 |
<p>PURPOSE:To constitute the equipment so that a program can be updated without exchanging a ROM, and updating of the program is facilitated by using an EEPROM as a program memory of the electronic equipment. CONSTITUTION:At the time of regular operation, CPU 11 reads out an instruction stored in a EEPROM (electrically erasable PROM) 12 and executes it. In the case of updating a program written in the EEPROM 12, a switch 16 is turned on and in a gate 15, the write signal/WE of the EEPROM 12 is made active. In such a state, the CPU 11 executes an EEPROM writing program, reads-in the data from an I/O device 17 and writes it in the EEPROM. In such a manner, it becomes unnecessary to exchange the ROM, and the updation of the program is facilitated.</p> |
