| 摘要 |
<p>PURPOSE:To decrease the power consumption by actuating a clock oscillating circuit of a high frequency only in a fast processing state. CONSTITUTION:When a presetting state of a resetting circuit 8 is released, a crystal oscillator 22 is actuated. Thus the circuit 8 counts the prescribed number of pulses of the oscillator 22 and sets the output of the oscillator 22 at L. Thus the resetting state of a clock selecting circuit 7 is released and a clock signal of a low frequency is sent to a CPU 9 from a NAND gate 5 as a system clock. Simultaneously, a clock signal of an L level is also applied to a reset input R of the CPU 9. Thus the CPU 9 is ready to start and a computer is actuated by a system clock of a low frequency. In a fast processing state a crystal oscillator 23 starts its oscillation for output of a signal of a high frequency. Then the oscillator 23 is driven again at a low frequency when a fast processing action is over.</p> |
