| 摘要 |
<p>PURPOSE:To secure the long-time backup of the memory even with the small-size battery by varying the control system for the refresh of the dynamic memory between the normal operation mode and the mode of the backup time by the battery. CONSTITUTION:In the normal mode under which main body power source 22 is under the ON state, the operation is given to CPU21 and control means 24-26 with the power supply from power source 22 to give the write/read control or the refresh control of the data to dynamic RAM27. On the other hand, in the backup mode under which source 22 is under the OFF state, control means 25 and 26 have operation via battery power source 29 to give the refresh to RAM27. At the same time, detection means 23 detects the operation state of power source 22 and then delivers detection signal RES of H or L which indicates the normal mode or the backup mode. Signal RES is then turned into the reset or reset cancel signal of CPU21 and also contributes to switching of the control action in the both modes of means 25.</p> |
