Renesas Electronics Corporation

Renesas Technology Corp.

Hitachi Engineering Co., Ltd.

Hitachi Information & Control Solutions, Ltd.

Hitachi Information Control Systems, Inc.

Kei Ouchi

Yasuhiro Nakatsuka

Hiroshi Arita

Tomoaki Aoki

Yasuwo Watanabe

Yoshihiro Tanaka

Masanobu Tanaka

Kenji Furuhashi

Toshinobu Kanai

A transmit packet generated by a CPUis held in a buffer(). From among packets received from Ethernet(), a packet, a destination of which is a communication device, is held in the buffer(). A packet which should be transmitted is transmitted from a transfer judging circuitto Ethernetorthrough a MAC unitor. If a transfer judging circuitjudges a packet from the Ethernetto be a packet, a destination of which is another communication device, with reference to a destination MAC address, this packet is transferred to the Ethernetthrough MAC. If a usage rate of a transferring FIFO buffer() exceeds a threshold value in the process of transmitting a packet held in a transmitting FIFO buffer() on a priority basis, the priority order of a transfer packet is made higher than that of a transmit packet so that the transfer packet is transferred to the Ethernetorin preference to the transmit packet. This prevents a transfer buffer means from overflowing.

Packet communication device, packet communication system, packet communication module, data processor, and data transfer system

Packet communication device, packet communication system, packet communication system, packet communication module, data processor, and data transfer system

Growing community of inventors

Naka-machi, Japan

Kei Ouchi