| 摘要 |
<p>PURPOSE:To attain the test of an interface section with simple constitution by adding a folding circuit and a selection circuit to the interface section interfacing the terminal device of a digital telephone line or a line terminator. CONSTITUTION:A frame separation section 31 of the interface section receives a communication line signal and divides the signal into an information signal and a control signal, and stores the control signal in a microprocessor interface IF section 32. A frame composition section 33 extracts a data from the IF section 32, combines it with the information signal and assembles a frame and outputs the result as a communication line signal CMI. The output of the frame composition section 33 is inputted to a selection circuit 36 via an FF33 and the circuit 36 selects the reception signal or the feedback signal of the composition section 36 depending on a mode selection signal from the IF section 32 and inputs the result to a separation section 31. Selection circuits 37, 38 select whether the reception signal is applied to the input of a clock generating section 34 or the input of the circuit 34 is grounded for executing the reflecting test depending on a master slave switching signal or the feedback signal from the composition section 33.</p> |
