| 摘要 |
PURPOSE:To generate a stable dial pulse by using a counter. CONSTITUTION:A dial pulse number to be generated is written to an input/output port 1. This data is set to a counter 2 by a 4-bit parallel signal. When a controller 5 detects a trigger signal outputted from a trigger generator 4, the operation of the counter 2 is started. A discriminator 3 supervises an output of the counter 2 and detects that the output of the counter 2 is a final value, and outputs a signal to a trigger generator 8. The count end trigger signal is outputted by this signal. The operation of the counter 2 is stopped by this signal. A gate circuit 7 is opened corresponding to the time when the counter 2 is operated. During that time, a pulse signal generated by a pulse generator 9 is outputted from a terminal 10 as a dial pulse. |
