| 摘要 |
PROBLEM TO BE SOLVED: To generate a stable clock in spite of a period when reference time information is given. SOLUTION: A period counter 2 counts the period when reference time information is given. A time counter 1 presets the value of 'reference time information +1" and counts up time with a self generation clock. When reference time information is given, the value and the value of the time counter are subtracted in a subtracter 4. The subtracted result is divided by the value of the period counter 2. The divided result is converted into an analog signal by a D/A converter 7 and the oscillation frequency of VCO(voltage control oscillator) 9 is controlled. Since the division of the subtracted result of the subtracter 4 by the value of the period counter 2 is equivalent to the deviation of reference time information and the oscillation frequency of VCO 9, VCO 9 can stably be controlled in spite of the period when reference time information is given. |
