| 摘要 |
<p>PURPOSE: To monitor the battery voltage of a portable terminal equipment in a stop mode without operating a CPU. CONSTITUTION: When a CPU 9 is kept in a stop mode, the output of an A/D converter 3 is compared with the value set by the registers 5a to 5c by the comparators 7a to 7c respectively. When the drop of the battery voltage is detected, the CPU 9 is started again by a start circuit 11 and performs the control by an interruption. As a result, the battery voltage can be monitored at a low level of power and even in a stop mode. Then the consumption of a battery 1 can be minimized.</p> |
