| 摘要 |
<p>PURPOSE:To eliminate the need for the operation of a changeover switch and confirming operation and to obtain an easy-to-use system by switching automatically programs that a central processing unit executes after being reset according to the output data value of a time-limit delay circuit. CONSTITUTION:A time constant circuit composed of a resistance 7 and a capacitor 8 which are connected to power circuits 2-4, and a reset switch 6 are connected to the reset terminal of the central processing unit (CPU) 1. Further, a storage device A composed of a ROM 14 and a RAM 15, etc., are connected to the CPU 1 through a gate 13. In this case, a gate 12 is connected to the midpoint of connection between a resistance 18 having a resistance value R2 and a capacitor 19 with a capacity value C2 to constitute the time-limit delay circuit T for mode switching. Consequently, a program is loaded on the RAM 15 by the CPU 1 after the power source is turned at a specific level in the process of an increase in the large time constant C2R2 of the time-limit delay circuit T, and a program in the RAM 15 is executed automatically after said program is executed.</p> |
