Hitachi, Ltd.

Katsuyoshi Onishi

Osamu Takada

Koichi Kimura

Mitsuhiro Yamaga

Toshihiko Ogura

Ken Watanabe

Kazuo Sugai

Naoya Ikeda

Hiromichi Enomoto

Yoshihiro Takiyasu

Toshiaki Koyama

Kunio Hiyama

Kazunori Nakamura

Yasushi Shibata

Hisaaki Shibata

Masahito Sasaki

Kazuko Ito

A display control system provided between a computer and a display device includes a plurality of display control LSI's for data transfer and also displays image data stored in a plurality of image memories having planes on the display device by controlling plane groups which include one or more planes. Each display control LSI includes an enable generator for generating a synchronization enabling signal in accordance with LSI designation information and an input/output buffer for outputting a synchronization signal in response to the enabling signal. A synchronization signal from one of the plurality of display control LSI's designated by the LSI designation information is supplied to the plurality of display control LSI's inclusive of the designated display control LSI through a signal line to allow the plurality of display control LSI's to operate with each other, thereby making it possible to produce and display data to be simultaneously on the display device.

Image display control system

An internetworking apparatus which handles a scale of a network flexibly without degrading high speed operation. A router manager and a plurality of routing accelerator modules for performing routing are connected to one another through a high speed bus, and a plurality of communication ports are connected to the respective routing accelerators independently of one another. The plurality of routing accelerators can perform the routing for reception data packet at high speed. If more routing accelerators are provided, the disposal to the networks having a small scale to a large scale can be readily realized.

Internetworking apparatus for connecting plural network systems and

A frame strip method for a bridge circuit for transparently forwarding data between a plurality of LANs (Local Area Network) without frame infinite circulation. The numbers of transmission/receive frames are counted. In counting the number, the validity/invalidity of a transmission frame is judged in accordance with the kind of the transmission frame. The validity/invalidity and strip/receive of a receive frame are judged in accordance with the kind of the receive frame. In accordance with the numbers of valid transmission/receive frames, a receive frame is stripped from the transmission line if the condition of (transmission frame number)&gt;(receive frame number) is met.

Frame strip method and apparatus therefor

Frontend LANs connecting plural stations are connected to plural nodes of a backbone LAN respectively. The backbone LAN is constituted by plural physical or logical links, and each node corresponds to each frontend LAN. A first data block is segmented into one or plural second data block units of fixed length and transferred to destination nodes, a bridge is provided in order to assemble the second data blocks into the first data block. The bridge can transmit the second data blocks to arbitrary links, and the receiving is performed through one link. The bridge a decoder also has a decoder for decoding whether the learning should be performed or not, based on the learning indication information existing in the second data block including the routing information.

Bridge apparatus and a communication system between networks using the

The present invention relates to an address filter method and unit to be used in a bridge unit or the like for connecting networks. The address filter unit carries out an address filter processing between a plurality of networks by using address information extracted from an incoming information frame registered in an entry table. In order to improve the processing efficiency of the address filter processing, the address filter unit includes timers corresponding to each address information registration, timer updating means for sequentially and intermittently advancing each timer value, and means for deleting registration of the address information corresponding to the timers from the entry table when a timer value becomes equal to or above a predetermined value. Further, the address filtering method includes a first step for sequentially generating, as an address of the entry table, a function (fi(a), i=1 to n) of a source address extracted from an incoming information frame at the time of a registration in the entry table or a destination address (a) extracted from an incoming information frame at the time of a retrieval from the entry table, a second step for deciding whether or not address information can be registered in an address generated in the first step in the entry table, at the time of registration, and a third step for deciding whether or not address information registered in an address generated in the first step in the entry table is desired address information, at the time of retrieval.

Address filter unit for carrying out address filter processing among

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Yokohama, Japan

Katsuyoshi Onishi