| 摘要 |
PURPOSE:To read information controlling a printer or the like written in a RAM as needed and to keep the content of the information without the backup power supply when the power is turned off. CONSTITUTION:A nonvolatile EEPROM 17 is provided separately from a RAM 16 to store control information. When the power is turned on, the control information is read out from a RAM 16 and rewritten as needed. When the power is turned off, the control information of the RAM16 is transferred to the EEPROM while the power supply voltage drops. As a result, the control information is kept in the EEPROM 17 stably without the backup power supply when the power is turned off, and can be written from the EEPROM 17 to the RAM 16 at the next power supply even though the control information of the RAM disappears. |
