| 摘要 |
PROBLEM TO BE SOLVED: To provide a modem that can be recovered to a communication state in a few seconds after power return when reactivated by the power return after stopping by interruption of power supply.SOLUTION: A modem 10 comprises: a modulating/demodulating part 12 performing modulation and demodulation of a signal; a memory 16 storing setting information on the modulation and demodulation; a controller 17 controlling the modulating/demodulating part 12 on the basis of the setting information; a power supply circuit 19 accepting supply of power from an external power supply line and supplying a power to the modulating/demodulating part 12, the memory 16, and the controller 17; an oscillator 18 operating by accepting supply of power from the power supply circuit 19 and supplying a clock signal to the modulating/demodulating part 12, the memory 16, and the controller 17; and a backup power supply circuit 20 supplying a battery power supply to the memory 16 and the controller 17 when detecting a power supply interruption state in which no power is supplied from the external power supply line. The oscillator 18 stops an operation in the power supply interruption state. The memory 16 and the controller 17 stop operations while holding the setting information by supply stop of the clock signal. |
