| 摘要 |
<p>An electronic device comprising a time information acquisition unit which acquires time information representing present time from an external device, an update unit which updates reference time stored in a reference time storage unit to time represented by the latest time information acquired by the time information acquisition unit each time the time information is acquired, a counter circuit which is formed by hardware and updates its count value at fixed cycles, an elapsed time measurement unit which measures an elapsed time since the update of the reference time by use of the counter circuit, a present time calculation unit which calculates present time by adding the elapsed time to the reference time stored in the reference time storage unit, and a response unit which makes the present time calculation unit calculate the present time and outputs the calculated present time if a present time output request is issued.</p> |
