| 摘要 |
<p>PURPOSE:To prevent held data from being erased carelessly, by detecting the fact that terminal voltage of a backup capacitor exceeds memory holding voltage, when an electric power supply is turned on or when service interruption is reset, and outputting a signal of a prescribed level. CONSTITUTION:In case when service interruption occurs in the course of operation of a microcomputer 6, terminal voltage of a backup capacitor 5 decreases gradually, and backup of a memory is executed. When the service interruption is reset, a transistor 8 becomes an on-state. In this case, if terminal voltage of the capacitor 5 exceeds 2.08V, a transistor 9 becomes an on-state. The microcomputer 6 executes the halted program continuously when voltage applied to a holding and resetting terminal H/R is in a power supply voltage level. If the terminal voltage of the capacitor 5 is <=2.08V, the microcomputer 6 resets the internal circuit and also initializes the memory.</p> |
