| 摘要 |
In a tuning apparatus of frequency synthesizer system comprising an input circuit means including a channel switch and a shift switch, a microcomputer and a phase-locked loop circuit including a programmable divider, a method for selecting one of a plurality of television channels of different frequencies by the channel switch and adjusting the frequency of one of the television channels selected by the shift switch, which method comprises the steps of providing a first signal from the channel switch to the microcomputer, setting up the ratio of division of the programmable divider according to the first signal, providing a second signal from the shift switch to the microcomputer, varying the ratio of division of the programmable divider according to the second signal, causing the microcomputer to cyclically monitor the presence or absence of the first and second signal, and repeating said setting step when the first signal is detected as a result of the monitoring by the microcomputer, but repeating said varying step when the second signal is detected as a result of the monitoring by the microcomputer.
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