Denso Corporation

Nippondenso Co., Ltd.

Toyota Jidosha Kabushiki Kaisha

Akihiro Sasaki

Nobutomo Takagi

Yasushi Kanda

Hideaki Ishihara

Akihiro Tanaka

Tomohisa Kishigami

Kouichi Maeda

Kazunori Sakai

Shigeru Uehara

Yasushi Shinojima

Tengo Fujii

Tomonori Suzuki

Takashi Harada

Keiji Horiba

Kentaro Asai

Masaki Takashima

Kyouichi Suzuki

Masato Kume

Hiroshi Honda

Gorou Inoue

Terutaka Maruyama

Shinji Shimoke

A transmission system is provided which includes a transmitter working to transmit data on a frame basis and a receiver. If two frames having the same data are inputted in sequence to the receiver, the receiver decides that it is unnecessary to decode a following one of the frames and stops receiving or decoding it. This results in decreases in operation load and power consumption of the receiver.

Frame data transmission system having power save structure

Data formulated according to a user's request signal is transmitted from a transmitter device to a receiver device under a wireless or a wired system. The transmitter device includes a transmission controller that formulates the data to be transmitted and memorizes the request signal as a backup signal. If the data transmission is not completed due to a power source trouble such as a voltage drop, the data to be transmitted is automatically formulated again based on the backup signal and sent out to the receiver. If the data transmission is successful, the backup signal is eliminated from a memory. Thus, the data requested by the user is transmitted without fail even if the transmitter becomes temporarily inoperative.

Transmitter device having means for automatically transmitting data remaining therein upon its re-activation

In a multiplex communication system, a communication bus is connected to a communication bus disconnect control device. In the communication bus disconnect control device, a control section generates a communication bus disconnect signal when a trouble of the communication bus is detected. A communication bus disconnect device is provided for separating the communication bus into at least two communication bus groups in response to the communication bus disconnect signal.

Multiplex communication system

To provide a microprocessor that can perform high-speed CRC code generation and can be implemented simply and at a low cost, a microprocessor has, at a part of a data input path to a shift circuit which is conventionally installed in an ALU of the microprocessor to execute shift commands, one bit of data that corresponds to the path, an exclusive OR circuit, which computes the exclusive OR of an uppermost bit of byte data and a bit data, is provided. For this circuit, a result according to a generating polynomial such as &lsqb;X,&plus;X,&plus;X,&plus;X,&plus;1&rsqb; is determined on the basis of the installation location of the exclusive OR circuit along the path, and by setting an initial value to the byte data, inputting one bit of the transmission data sequentially to the bit data and operating the shift circuit, a computed result for the CRC code is derived. Consequently, for the microprocessor, the CRC code can be generated at a high speed using the computation commands of the CRC code section. Corresponding techniques for error-checking of received data are also disclosed.

Microprocessor having built-in CRC section and method for performing CRC operations using the same

In a data communication system in which many nodes are connected to a common data bus so that each node can communicate with other nodes, a data frame to be transmitted from a node to other nodes includes a message having a variable length interposed between a signal indicating the length of the message and a signal indicating the end of the message in the frame. The message and the signals are coded according to a coding rule such as NRZ, and a bit stuffing rule is applied to the signal indicating the length of the message and the message while another rule violating the bit stuffing rule is applied to the signal indicating the end of the message. When the message length is changed due to noise or other causes in the course of data transmission, the signal indicating the end of the message is clearly detected at a receiving end because it is coded according to a rule different from the rule applied to the message and other signals. Further, since the length of the message actually received at the receiving end can be compared with the signal indicating the length of the message, transmission error can be detected without fail.

Data communication system and electronic control unit used therein

A relaying controller communicates with an external tool through a first communication path based on a first communication protocol and communicates with sub-controllers through a second communication path based on a second communication protocol, thus relaying communications between the external tool and the sub-controllers. The relaying controller includes a rewritable non-volatile memory having predetermined storage areas divided in correspondence with the sub-controllers. The relaying controller transmits, in response to a memory reading request from the sub-controller, a stored data in the corresponding storage area to the sub-controller through the second communication path, and writes, in response to a memory writing request from the sub-controller, a writing data received through the second communication path in the corresponding storage area. That is, the relaying controller executes accesses of the sub-controllers to the non-volatile memory.

Distributed processing type control system

A light sensing apparatus for different control systems includes a photosensitive element which generates a light current depending on light incident thereto. A pre-circuit connected to the photosensitive element is operative for generating separate basic signals in response to the light current generated by the photosensitive element. Processing circuits connected to the pre-circuit are active simultaneously for converting the basic signals generated by the pre-circuit into conversion-resultant signals having different forms respectively. The conversion-resultant signals are outputted to the control systems respectively. At least one of the processing circuits may include an oscillation circuit which oscillates at a frequency depending on related one of the basic signals generated by the pre-circuit.

System for automatically sensing light in a predetermined range and

A communication apparatus is used in a communication system, having a communication line, where an operation timing in each of the communication apparatus is coupled to the communication line and synchronized with the received signals in each of the communication apparatus. This communication apparatus comprises a signal-chip microprocessor having a central processing unit for executing main and interruption processing, a register storing data to be transmitted next, an output buffer for transmitting the transmission data, and an edge detector for detecting an edge in the communication line. The output buffer is directly responsive to an edge detection circuit, so that the transmission data can be immediately transmitted in response to the detection of an edge without a variable delay time caused by the operation condition which may be varied by the interruption processing or like.

Communication apparatus with collision detection and edge detection for

A circuit arrangement disposed in a node within a local area network is connected to a communication bus within the local area network. The circuit arrangement includes an input circuit for introducing data from the communication bus into the node. A node state detecting device is operative for detecting whether or not the node is in a stand-by state. A power feed suspending device is operative for suspending power feed to at least part of the input circuit when the node state detecting device detects that the node is in the stand-by state. A power feed restarting device is operative for monitoring a voltage at the communication bus, and restarting the power feed to at least part of the input circuit when the voltage at the communication bus becomes equal to a level indicating reception of data. A protective circuit is operative for protecting the input circuit from an abnormal current which flows from the communication bus.

Communication circuit for local area network

For a system which receives a sleep command to terminate the application of machine clock signals to a microprocessor and which clocks control execution time and stabilization time after the return from sleep control and resumes the supply of the machine clock signal, the clocking device for each of the time durations is implemented using a small-scale timing device. Following a sleep command from a microprocessor, sleep control, which terminates the operation of the main oscillator and the machine clock generation circuit that generates the machine clock signal based on the oscillation of the main oscillator, is started. Then, counting the oscillation signal from an RC oscillator used for clocking using an RC timer, the lapse time after starting sleep control is started and if the clocked time reaches a predetermined time, the main oscillator is reactivated. After reactivating the main oscillator, the RC timer is reset so that it begins to count the time thereafter starting from '0' and if the clocked time reaches the time needed for the oscillation of the main oscillator to stabilize, the machine clock generation circuit resumes its operations.

Driving circuit for a microcomputer that enables sleep control using a

In a receiving device, when a communication signal, which changes between low level and high level, is received via a filter circuit, an occurrence of an edge of the filtered received signal is monitored. Upon detection of the edge, a type of the edge, that is, whether the edge is a leading or trailing edge, is determined. Depending on the type of the edge, one of preset times prestored corresponding to types of the edges, is selected and starts to be measured. When the selected preset time elapses, the filtered received signal is sampled. With this arrangement, even when a filtering time of the filter circuit differs depending on a type of the edge of the communication signal, a constant sampling timing relative to the communication signal can be achieved irrespective of whether the detected edge is the leading or trailing edge.

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Anjo, Japan

Akihiro Sasaki