| 摘要 |
PURPOSE:To reduce electric power consumption by providing a count means which counts low-frequency signals while the drop of a source voltage is detected, time signal generating means which generates time signals and memory means. CONSTITUTION:A time signal generator is so constituted that current flows transiently for a prescribed period to the time signal generating means 4 in a backup state 9. The count value read out of the frame counter 3 is time- converted and is then added to the time data saved in the memory 5 through a data bus Bg during a prescribed period. The circuits which operate during the operation stop of the time signal generating means 4 in this case are only the min. circuits including the frame counter 3, the memory 5, a source voltage detecting circuit 6, etc., and the operation time is extremely short as shown in 10, 10a and, therefore, the electric power consumed by a capacitor for backup is extremely small. |
