JPS6384399A - Key telephone system - Google Patents

Abstract

PURPOSE:To decrease the number of data and control buses, etc., and to simplify a key telephone set by performing transmission and reception between a central processor and plural interface circuits on a time-division basis by using serial data. CONSTITUTION:The central processor 11 in a key telephone system main device 1 inputs control data and circuit numbers of the interface circuits 14a-14c at destinations of transmission to a control data input/output circuit 13 according to a program stored in a recording circuit 12, and inputs and outputs the control data. This circuit 13 writes the control data at a place in one frame of a serial sent signal corresponding to the circuit number of a circuit specified among the circuits 14a-14c, and transmits it to the circuits 14a-14c on a time-division basis by a control data signal line 19. The control data input/ output circuits 15 of the respective circuits 14a-14c read respective control data by using respective synchronizing signals from clock and frame synchronizing signal lines 18 and 17 to simplify the telephone set.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a button telephone device, and more particularly to a button telephone device that transmits control data between a central processing unit and a plurality of interface circuits in a time-sharing manner using serial data.

[Conventional technology]

Conventionally, this type of button telephone device has required multiple data buses, signals indicating the direction of data, signals for specifying the interface circuits, etc. to transmit control data between the central processing unit and the multiple interface circuits. , using several control buses.

[Problem that the invention seeks to solve]

In the conventional button telephone device described above, control data is transmitted between the central processing unit and the plurality of interface circuits using parallel data, so the signal line (data bus) for transmitting and receiving the control data and the plurality of interfaces are There is a drawback that a large number of signal lines (control buses) must be wired to select one circuit from among the circuits.

[Means for solving problems]

The button telephone device of the present invention includes an interface circuit for connecting a plurality of extension telephones, a single telephone, a central office line, etc., and a central processing unit that controls the interface circuit. An input/output circuit is provided for transmitting and receiving control data in the form of serial data via a signal line between the respective interface circuits under time-division control i-.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention.

In the figure, the present embodiment is comprised of a key telephone main device 1, an extension telephone 2, a standalone telephone 3, and a central office line 4.

The button telephone main device 1 includes an extension telephone 2. Single telephone 31
interface circuits 14a, respectively connected to the central office lines;
, 4b, 14c and each interface circuit 14a, 14
Control data input/output circuit B15 built in b, 14c, and memory circuit 1 storing data and control programs
2, a central processing unit 1 which controls the entire key telephone main unit 1], respective control data input/output circuits B15 and frame synchronization signal lines 17. Clock signal line 18. A control data input/output circuit A]3 which is connected by a control data signal line 19 and sends a frame synchronization signal and a clock signal to each control data input/output circuit B15 under the control of the central processing unit 11, and transmits and receives control data signals. We are prepared.

FIG. 2 is a frame configuration diagram showing an example of control data transmitted and received on the control data signal line of FIG. 1.

Next, the operation of this embodiment will be explained.

First, the central processing unit 11 in the button telephone main device 1 interfaces the control data and the destination to the control data input/output circuit A13 in order to input and output the control data signal in a time-sharing manner according to the program stored in the memory circuit 12. Enter the circuit number data of the circuit. As shown in FIG. 2, one frame of the serial transmission signal synchronized with the common lock signal that operates the entire button telephone main unit 1 is divided in time by the number of interface circuits. The control data input/output circuit A1.3 in which the control data and circuit number data of the destination interface circuit are written is a temporal delimiter that corresponds to the circuit number of the specified interface circuit within one frame of the serial transmission signal. After writing the control data to the specified location, the interface circuits 14a, 14b, 14
c via the control data signal line 19.

In each interface circuit 1'4a, 14b, 14c, the control data input/output circuit B15 in each interface circuit receives the clock signal sent from the clock synchronization signal line 18 and the frame synchronization signal line 17 and the frame synchronization signal indicating the break between frames. The interface circuit 14a
, 14b.

14c from among the serial control data signals that are continuously sent to each interface circuit 14a.
, 14b, 14c.

Similarly, when transmitting control data from each interface circuit 14a, 14b, 14c to the central processing unit 11 side, each interface circuit 14a.

14b and 14c write their respective control data into their respective control data input/output circuits B15 during the time allocated to them within one frame, and send the control data signal line 19 to the control data input/output circuit A13 on the central processing unit 11 side. to be transmitted via. The central processing unit 11 reads the control data after knowing from which interface circuit the control data is sent based on the position of the control data within the frame.

Incidentally, since serial data is transmitted between the interface circuit 14a and the extension telephone 2, the above-mentioned serial control data sent from the central processing unit 11 to the interface circuit 14a via the control data input/output line A13 can be transmitted to extension telephone 2 without being converted into parallel data.

Conversely, control data from extension telephone 2 is sent to central processing unit 1.
The same goes for sending 1/\.

[Effects of the Invention] As explained above, the present invention transmits and receives control data between the central processing unit and the plurality of interface circuits in a time-sharing manner using serial data. This has the advantage that it is not necessary to use a large number of signal lines such as data buses and control buses.

In addition, when transmitting and receiving control data to and from the extension telephone through the interface circuit for controlling the extension telephone, there are advantages such as there is no need to perform parallel-to-serial conversion as in the past because the data is transmitted to the extension telephone as serial data. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a frame configuration diagram showing an example of control data transmitted and received by the control data signal line of FIG. 1. 1... Key telephone main device, 2... Extension telephone, 3.
...Independent telephone, 4.. Office line, 11.. Central processing unit, 12.. Memory circuit, 13.. Control data human output circuit A, 1.4. a, 1.4b, 14 C.-Interface circuit, 1-5... Control data human output circuit I3.1
7... Frame synchronization signal line, 18... Clock signal line, 19... Control data signal line.

Claims (1)

[Claims] In a button telephone device comprising an interface circuit for connecting a plurality of extension telephones, a single telephone, a central office line, etc., and a central processing unit that controls the interface circuit, a signal line between the central processing unit and each of the interface circuits. What is claimed is: 1. A button telephone device comprising an input/output circuit for transmitting and receiving control data in a time-division manner as serial data via the serial data.