| 摘要 |
PURPOSE:To eliminate the need for a signal generating circuit by outputting a dial signal and a control signal by a programmable frequency dividing circuit in common, and outputting the frequency of a control signal which corresponds to the channel of a telephone set by varying the frequency division ratio of a frequency dividing circuit. CONSTITUTION:The control part 33-2 of a master device receives an applied dial number and a signal generated by the hook on, etc., of an outgoing and an incoming call to outputs a switch selection signal to signal selection switches 44 and 45, and also to outputs a signal for a high group which corresponds to the dial number to a code converting circuit for a tone signal and a code converting circuit 41 for the dial signal. Then, a programmable frequency dividing circuit 43 outputs a reference signal from a reference clock generating circuit 33 by varying its frequency division ratio corresponding to the code-converted signals. A frequency selecting circuit 46 removes higher harmonics and sends the remainder to signal selection switches 44 and 45. The signal selection switches 44 and 45 are turned on by the switch selection signal of the control part 33-2 to selectively output the dial signal and control signal during the period. |
