摘要 |
PURPOSE:To realize a real time clock with a low power consumption and to accurately recognize the residual capacity of batteries when a printing operation is started even in the waiting state for a key entry. CONSTITUTION:This device is provided with a frequency divider circuit 2 capable of selectively frequency-dividing the clock in several ways, a count pulse generation circuit 3 for outputting count up signals and count interval signals at every certain interval of time from the frequency-divided clock, a CPU 4 for the clock for performing counting for the clock and an interval discrimination circuit 5 for controlling the interval of the time of the count pulses for the clock based on the level of a battery voltage 7. The frequency division of the clock of the frequency divider circuit 2 is changed by the control information of the interval discrimination circuit 5. Thus, the CPU 4 prolongs the interval of the counted pulses when the capacity of the battery is reduced or the battery is left for a long time and the power consumption can be reduced to the utmost. |