Hitachi, Ltd.

Renesas Electronics Corporation

Renesas Technology Corp.

Yasuhiro Sagesaka

Toru Baji

Tetsuya Nakagawa

Koki Noguchi

Yuji Hatano

Suguru Fujita

Yoshiyuki Sato

Daisuke Oshida

Junichi Tatezaki

Hideo Wada

Masafumi Miyamoto

Yoshifumi Kawamura

Takeshi Itome

Atsushi Ogane

Isao Kodama

To provide a communication device that can suppress radio wave interference in communication using a plurality of frequency signals in a simply method, a communication device includes a first communication unit that communicates with a first external device by using a first frequency signal, a second communication unit that communicates with a second external device by using a second frequency signal, and a control unit that controls, when one of the first and second communication units transmits data to a corresponding one of the first and second external devices, the other of the first and second communication units not to receive data.

Communication device

An on-vehicle communication device has a communication unit which communicates with a roadside device, a roadside device position information storage unit which stores in advance first position information indicating a position of the roadside device, a vehicle position information acquisition unit which acquires second position information indicating a position of the vehicle, an approach decision unit which decides whether the vehicle approaches the roadside device on the basis of the first position information stored in the roadside device position information storage unit and the second position information that the vehicle position information acquisition unit acquires and a communication control unit which switches a state of the communication unit from a power-saving state to a non-power-saving state in a case where the approach decision unit decides that the vehicle approaches the roadside device.

On-vehicle communication device, communication control method and vehicle

Provided is a high-speed and light-weighted authentication system that makes IP address filtering possible and does not impair real-time property even on a network including many and unspecific entities (communication devices). In a communication system that a plurality of communication devices are coupled together such that mutual communication is possible over the network, the communication devices communicate with a server under a secure environment, when authentication has been obtained from the server, random seeds of the same value and individual identifiers are issued to them, each communication device generates the IP address that includes a pseudorandom number and the identifier, and the communication devices establish communication between the communication devices that include the pseudorandom numbers that are mutually the same in their IP addresses.

Communication system, communication device, vehicle and communication method

A low cost, a low power consumption and a small size are three very important factors for a mobile communication terminal. A great problem is posed by the conventional technique using a DSP and a CPU independent of each other which requires two external memory systems. Also, two peripheral units are required for data input and output of the DSP and CPU. As a result, an extraneous communication overhead occurs between the DSP and the CPU. The invention realizes a mobile communication terminal system by a DSP/CPU integrated chip comprising a DSP/CPU core () integrated as a single bus master, an integrated external bus interface () and an integrated peripheral circuit interface. The memory systems and the peripheral circuits of the DSP and the CPU can thus be integrated to realize a mobile communication terminal system low in cost and power consumption and small in size.

Terminal apparatus

A low cost, a low power consumption and a small size are three very important factors for a mobile communication terminal. A great problem is posed by the conventional technique using a DSP and a CPU independent of each other which requires two external memory systems. Also, two peripheral units are required for data input and output of the DSP and CPU. As a result, an extraneous communication overhead occurs between the DSP and the CPU. The invention realizes a mobile communication terminal system by a DSP/CPU integrated chip comprising a DSP/CPU core ( ) integrated as a single bus master, an integrated external bus interface ( ) and an integrated peripheral circuit interface. The memory systems and the peripheral circuits of the DSP and the CPU can thus be integrated to realize a mobile communication terminal system low in cost and power consumption and small in size.

Apparatus has a microprocessor including DSP and a CPU integrated with each other as a single bus master

Terminal

A base station (5) comprises a base transmitter (6) for transmitting information optically to a plurality of portable stations (1 to 4) at such a predetermined time interval as is designated by portable station designating information. Each of the portable stations (1 to 4) comprises a potable transmitter (7) for transmitting information optically to the base station (5) in response to the transmission, which is designated by the portable station designating information coming from said base station (5), and within the range of the aforementioned time interval immediately after said transmission. Transmissions (ACK1 to ACK4) from the mating portable stations to the base station are individually inserted between the interval periods of the transmissions (REQ1 to REQ4) from the base station (5) to the portable stations (1 to 4) so that the single base station performs optical communications with the plurality of portable stations in a half-duplex time sharing manner.

Information transmitting/processing system

A data processor comprises a plurality of registers 1 (registers a to d), a plurality of data saving stack memory devices 2 coupled to the registers 1 for exclusive use thereof, respectively, and an instruction decoder for decoding instructions for controlling the registers 1 and the data saving stack memory devices 2 in accordance with the result of the instruction decoding. In response to an instruction 'PUSH', the contents of the registers 1 (registers a to d) are selectively saved to the data saving stack memory device 2. In response to a instruction 'POP', the contents of the data saving stack memory devices 2 are selectively restored to the registers 1 (registers a to d). Each of the instructions 'PUSH' and 'POP' has a field for indicating need or needlessness of the saving and restoration for each of the registers 1 and each of the data saving memories 2.

Growing community of inventors

Kodaira, Japan

Yasuhiro Sagesaka