| 摘要 |
PURPOSE:To protect the storage contents of a RAM when a power supply is cut off by transferring collectively data to an EEPROM from the RAM with stand-by start within the RAM. CONSTITUTION:When the power supply voltage drops, a power supply voltage detecting circuit 31 detects this voltage drop and a stand-by control circuit 30 is started to send a control signal to a nonvolatile RAM 24. Then all storage contents of a RAM 24a storing various data within the RAM 24 are collectively transferred to a rewritable ROM 24b by the control signal. These storage contents are held although the power supply of a computer is completely cut off. |
