JPH0522461A - Synchronizing terminal station equipment - Google Patents

Abstract

PURPOSE:To eliminate the need for wiring with a clock supply device for an extended device. CONSTITUTION:A clock reception section 2 receives a clock signal 7 from a clock supply device 1. An IC level signal conversion section 9 converts a received clock signal 7 into a signal of an IC level and distributes the result. An external clock signal output section 5 outputs a signal converted into an IC level to an external device. An external clock signal input section 6 receives an external IC level signal. A clock selection section 3 selects either the distributed IC level signal or the external IC level signal and outputs the selected signal to a system section 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synchronous terminal device, and more particularly to a synchronous terminal device having an input / output unit capable of inputting / outputting an external clock.

[0002]

2. Description of the Related Art A conventional synchronous terminal device, as shown in FIG. 2, receives a clock signal 25 from a clock supply device 22 and converts it into an IC level signal.
And a plurality of system units 23 controlled by the IC level signal.

[0003]

When the above-mentioned synchronous terminal equipment is expanded, as shown in FIG. 2, the clock signal 25 from the clock supply device 22 is supplied to each synchronous terminal equipment. . Therefore, it is necessary to add the clock output unit 24 of the clock supply device 22 every time the addition is performed. It is also necessary to connect the clock supply device 22 and each synchronous terminal device.

[0004]

A synchronizing terminal device of the present invention comprises a receiving section for receiving a clock signal from a clock supply apparatus, and a signal converting section for converting the received clock signal into an IC level for distribution. A signal output unit for outputting the signal converted to the IC level to the outside, and an IC from the outside
A signal input section for inputting a level signal, and the I
It has a selection unit for selecting one of a C level signal and an IC level signal from the outside.

[0005]

The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an embodiment of the present invention.

In this embodiment, in the synchronous terminal device 8 which operates depending on the clock signal of the clock supply device 1, the clock receiving section 2 which receives the clock signal 7 from the clock supply device 1 and the received clock signal. An IC level signal converter 9 for converting 7 into an IC level for distribution, an external clock signal output unit 5 for outputting the signal converted into the IC level to the outside, and an external clock signal for inputting an IC level signal from the outside An input unit 6 and a clock selection unit 3 for selecting one of a distributed IC level signal and an external IC level signal and outputting the selected signal to the system unit 4 are provided.

In this way, in the expansion device 10, the external clock output unit 15 and the external clock input unit 1 of the expansion rack are installed.
The connection of 6 eliminates the need to receive the clock signal 7 directly from the clock supply device 1. Further, the clock signal receiving section 12 and the IC level converting section 19 are unnecessary.

[0008]

As described above, according to the present invention, a circuit for converting a clock signal from a clock supply device to an IC level for distribution, a circuit for outputting a signal converted to the IC level to the outside, and an external circuit. By providing a circuit for selecting one of the IC level signals of 1), it is not necessary to add the clock output unit of the clock supply device every time the synchronous terminal device is added. Also, the number of wires between the clock supply device and the synchronous terminal device is reduced. Further, when the synchronous terminal devices are adjacent to each other, by inputting the clock signal of the external clock output section to the external signal input section, there is an effect that the clock signal receiving section becomes unnecessary.

[Brief description of drawings]

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

FIG. 2 is a block diagram of an example of a conventional synchronous terminal device.

[Explanation of symbols]

 1 Clock Supply Device 2, 12 Clock Reception Unit 3, 13 Clock Selection Unit 4, 14 System Selection Unit 5, 15 External Clock Signal Output Unit 6, 16 External Clock Signal Input Unit 7 Clock Signal 8 Synchronous Terminal Equipment 9, 19 IC Level signal converter

Claims (1)

Claim: What is claimed is: 1. A receiving unit that receives a clock signal from a clock supply device, a signal conversion unit that converts the received clock signal into an IC level and distributes it, and a signal conversion unit that converts the received clock signal into the IC level. A signal output unit for outputting the external signal to the outside, a signal input unit for inputting an external IC level signal, and a selection unit for selecting one of the distributed IC level signal and the external IC level signal. A synchronous terminal device having.