| 摘要 |
<p>PURPOSE: To reduce the power consumption of A system by restarting the operations of an internal clock oscillation means and a central processing means when the charging level of an electric charging means stops temporarily and exceeds a specific value. CONSTITUTION: When a CPU 12 enters a stop state, an open drain 17 is turned ON temporarily and electric charges accumulated in a capacitor 15 are discharged to the ground 18, so that the terminal voltage V of the capacitor 15 falls down to zero. Then when the capacitor 15 is discharged, the CPU 12 turns OFF the open drain 17 again. Thus, the open drain 17 is put back into the OFF state and the capacitor 15 begins to be charged with electric charges, so its terminal voltage V gradually rises and exceeds the set value. When the terminal voltage across the capacitor 15 gradually rises to exceed the set value, an interruption control circuit 20 restarts the operations of the oscillation circuit 3 and CPU 12. The stop state continues for a while to suppress the power consumption.</p> |
