To easily and precisely regulate an internal time of a computer, even when time data is not acquired from a GPS satellite.
This time acquisition device is provided with a GPS receiver 22 for receiving a GPS signal, and an RTC task 36 for correcting a time of an RTC 37 periodically based on the time data of the received signal. An internal synchronization signal synchronized with a synchronization signal from the GPS satellite is generated by a counting operation based on an oscillation signal from an OCXO 35 having precision higher than that of the first oscillator in the RTC 37. When the time data is not extracted from the GPS signal, updating timing of the RTC 37 is synchronized periodically with the internal synchronization signal, a time clocked by an internal time piece in the RTC 37 is maintained thereby at high precision, even when the time data is not acquired for a long time from the GPS satellite. A time progress is regulated to absorb a time lag such as a leap second, by controlling a count value of a timer 33 for generating the internal synchronization signal.
COPYRIGHT: (C)2006,JPO&NCIPI
Tomohiro Yashiro
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| JP8285970A |
Fumiaki Otsuka
Takaki Nishijima
Eri Koshishiba