US 5,208,831 AGranted

Network interface system

AssigneeKabushiki Kaisha Toshiba

InventorsMasaji Ueno, Akihito Nishikawa, Shinichi Iida, Hajime Shiraishi

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Abstract

It is an object of this invention to provide a novel network interface system which is able to connect automatically to the respective network stations having different data transfer speeds, in order to avoid the above problems. According to this invention, there is provided a detector and a selector in the communication interface to automatically select the appropriate data transfer speed. In the above structure, the speed of communication data transferred by a network is one of two detected by the detector which is able to detect a transfer speed and provide outputs at a first level signal when the transfer speed is at one level and outputs a second level signal when it is at a second level. The selecting means selects the frequency to connect a network station in response to the signal output from the detector. As a result, users need not select the module by themselves, the system automatically select the module.

Claims11

Dependent claims

A communications network interface system comprising:

means for receiving a network clock signal from a communications network at one of a plurality of predetermined frequencies;
means for amplifying the network clock signal received from the communications network and for generating an amplified signal;
detecting means, responsive to the amplified signal, for generating a detection signal to indicate which one of the plurality of preferred frequencies corresponds to the network clock signal received by the receiving means;
means, having a first input coupled to the amplified signal and a second input, for generating a voltage in accordance with a phase difference between the amplified signal on the first input and a signal on the second input;
a voltage controlled oscillator, responsive to the voltage generated by the voltage generating means, for generating a first clock signal at one of the plurality at predetermined frequencies;
means for dividing the first clock signal to generate a second clock signal at another one of the plurality of preferred frequencies;
and
means, responsive to the detection signal, for selecting one of the first clock signal and the second clock signals to generate a selected clock signal, and for applying the selected clock signal to the second input of the voltage generating means.

5 more elements

Dependencies are inferred from the claim text.