JP5192353B2 - Communication circuit, communication device, communication system, and communication device aggregation device - Google Patents

Description

  The present invention relates to a communication system that includes a plurality of communication devices and a communication line that connects the communication devices, and is intended to save space by consolidating the plurality of communication devices in a limited space. A communication circuit for realizing communication in accordance with the conventional communication protocol, a communication circuit including the communication circuit, a communication system including the communication circuit, and communication apparatus aggregation Relates to the device.

  In recent years, systems in which functions are assigned to a plurality of control devices, communication means are provided in each control device to exchange data with each other, and various processes are performed in cooperation have been used in various fields. Particularly in the field of vehicles, control shifts from mechanical control to electrical control, ECUs (Electronic Control Units) are arranged in the vehicle as a number of control devices, and each ECU is a CAN (Controller Area Network), LIN (Local In general, a configuration is used in which information is mutually exchanged via a network according to a protocol such as Interconnect Network) or FlexRay, and various processes are performed in cooperation and cooperation.

  The number of ECUs mounted on the vehicle increases because the functions of the vehicle realized by electrical control are increasing. In a communication system in which processing is performed in cooperation with a plurality of control devices as well as a system including an ECU mounted on a vehicle, failure and bugs can be realized by distributing the processing units divided into each control device. When a problem such as the above occurs, there is a case where the device is devised to improve the development efficiency and maintainability by facilitating isolation and handling. As described above, the number of control devices included as communication devices in the communication system increases, and the amount of data transmitted and received for cooperation / cooperation between the control devices tends to increase.

  When a communication device is connected to a communication line, a transceiver that realizes transmission and reception of communication signals in the physical layer is used. The number of transceivers connected to one communication line is limited for delay time, reflection avoidance, ringing prevention, and the like. For example, in the case of a CAN widely used as an in-vehicle network, a maximum of 30 units can be connected to a high speed CAN bus according to the standard, but in practice, operation is limited to a dozen or more units. .

  Although the number of communication devices included in a communication system is increasing, the number of communication devices connected to one communication line is limited. Therefore, the communication devices are divided into a plurality of groups, and the communication lines are divided into groups. In some cases, different communication lines are connected and relayed by a relay device (gateway device). In this case, the number of communication lines increases as the number of communication devices increases. However, particularly in the field of vehicles, the weight reduction of the entire vehicle is an important issue in consideration of the improvement of fuel consumption and the influence on the environment. The weight reduction is most affected by the weight reduction of the harness itself including various electric wires such as a communication line and a power supply line. Therefore, the weight reduction of the various electric wires themselves and the line saving in the in-vehicle communication system are desired. Furthermore, in order to secure the space in the vehicle as wide as possible and improve the comfort, the space allocated for the installation location of the ECU is limited.

  Patent Documents 1 and 2 relate to an in-vehicle communication system, and a concentration of ECUs that can reduce the installation space by accommodating a plurality of ECUs in a single housing, and can reduce power consumption by sharing a power supply circuit and a ground circuit. A containment box has been proposed.

  In a configuration that simply accommodates a plurality of ECUs, a transceiver for a protocol such as CAN, LIN, or FlexRay is required for communication between the ECUs even though each ECU is installed close to the housing. It becomes. In many cases, the transceiver is equipped with a function for performing communication between ECUs installed several tens of meters apart without any problem. In the case of being installed close to each other, these functions are not necessary, but the same one used for communication between ECUs that are installed separately is used. Furthermore, even if a plurality of ECUs are installed close to each other, the number of communication devices connected to a single communication line is limited. Therefore, the number of communication lines can be effectively reduced to save the line. I can't.

In the ECU centralized storage box disclosed in Patent Document 2, a configuration in which a network communication circuit of each ECU is shared is proposed. Specifically, each ECU is configured with a CPU and a memory mounted on a substrate, and not only a transceiver is provided for each ECU, but each ECU is a network for a protocol such as CAN. There is no controller (communication control means). The serial input / output unit of the CPU of each ECU is connected to a serial communication line, and the serial communication line is connected to a shared network communication CPU. That is, data transmission / reception of each ECU is performed directly from the CPU, and the network communication CPU is configured to perform processing equivalent to a transceiver of various protocols. As a result, network components in each ECU can be omitted, and the manufacturing cost can be reduced.
JP 2003-304083 A JP 2007-048890 A

  However, in the shared configuration of the network communication circuit disclosed in Patent Document 2, ECUs such as a microcomputer (hereinafter referred to as a microcomputer) configured to transmit and receive data via a network controller and a transceiver are used. It is necessary to change the existing basic configuration to transmit and receive data by serial communication between CPUs. Further, a network communication CPU for controlling the physical layer is required separately in order to appropriately execute transmission / reception.

  However, it is desired that a configuration in which the number of communication lines can be reduced by sharing communication resources in accordance with the conventional communication protocol without changing the existing basic configuration of the communication device. For this reason, the inventors have come up with an invention that allows a plurality of network controllers or respective channels to share a transceiver that realizes transmission and reception of communication signals to and from a communication line. When the network controller has a basic configuration for transmitting a response signal when it receives a data signal, in a configuration in which outputs from a plurality of network controllers are simply connected to a transceiver in common, the response signal is shared between the shared network controllers. The fact that there is a problem that a communication error does not occur even if a response signal from another communication device connected to the communication line should be received, even though it should not be received. Got.

  A problem in a configuration in which a plurality of network controllers are simply connected to one transceiver in common will be described. In the following description, an ECU in a CAN network is taken as an example.

  FIG. 8 simply shows a configuration diagram of a communication system including a plurality of ECUs. 8 is an ECU corresponding to CAN communication, and a plurality of ECUs 8, 8,... Are connected to the CAN bus 84. The ECU 8 includes a microcomputer 80 that is a CAN-compatible general-purpose microcomputer including a CPU 81 and a CAN controller 82. The input / output terminals Tx and Rx of the CAN controller 82 of the microcomputer 80 are connected to the CAN transceiver 83 to perform communication on the CAN bus 84. Realize.

  FIG. 9 is a time chart showing an example of signal levels at the input / output terminals Tx and Rx of the CAN controller 82 of the general-purpose microcomputer. The horizontal axis represents time, and the vertical axis represents the signal level at each terminal Tx, Rx. The signal level in the CAN bus 84 is shown at the bottom. As shown in FIG. 9, when the ECU 8 attempts to transmit a CAN message, the signal level of the output terminal Tx of the CAN controller 82 changes, the signal level on the CAN bus 84 is changed by the CAN transceiver 83, and the CAN message is transmitted. Is done. At this time, the CAN transceiver 83 monitors the CAN bus 84 and inputs it to the input terminal Rx of the CAN controller 82. As shown in FIG. 9, during output of the CAN message, the ECU 8 can recognize that the signal level at its output terminal Tx and the signal level at the input terminal Rx match each other, and that it has acquired the transmission right. Then, an ACK signal is transmitted to the CAN bus 84 from the other ECU 8 that receives the CAN message, and this is also input at the input terminal Rx of the CAN controller 82 of the ECU 8 that has obtained the transmission right. The CAN controller 82 of the ECU 8 that has obtained the transmission right can confirm that the ACK signal has been transmitted in response to the transmitted CAN message, and can determine whether communication with other ECUs 8 has been established or not.

  Note that the CPU 81 of the microcomputer 80, which is a CAN-compatible general-purpose microcomputer used for in-vehicle communication devices, is an OSEK / VDX (OSEK: Open systems and corresponding interfaces for automotive electronic) / VDX. : It has become necessary to be configured to perform processing based on a real-time OS (Operating System) such as the Vehicle Distributed eX ecutive) standard, and is being standardized. This is because power saving is required by a network management function described later.

  FIG. 10 shows a software configuration based on the OS corresponding to OSEK / VDX. The OS 801 corresponding to the OSEK / VDX standard has functions of COM (Communication) 802 and NM (Network Management) 803, and the CPU 81 executes an application 804 that realizes specific processing on the OS 801. The COM 802 is an OSEK-COM function that implements communication within the ECU 8, communication between the ECUs 8, 8,..., A message transmission / reception notification function to the OS 801, and the like. The NM 803 is an OSEK-NM function that manages the monitoring of the operation state of each ECU 8, 8,... Connected to the network, that is, the CAN bus 84, and shifts to the bus / sleep mode. The CAN controller 82, 82,... Of the ECUs 8, 8,... Can send and receive CAN messages such as whether or not to enter the sleep state by the function of the NM 803. All of the ECUs 8, 8,... Connected to the bus 84 are normally controlled such as transitioning to the sleep state as a whole when the transition to the sleep state becomes possible.

  When one CAN transceiver is shared by a plurality of CAN controllers in accordance with the conventional convention as described above, there are the following problems. FIG. 11 is a configuration diagram showing a configuration when a CAN transceiver is simply shared by two ECUs. Reference numeral 9 in FIG. 11 denotes an ECU aggregating apparatus that aggregates and realizes the ECUs 8a and 8b using general-purpose microcomputers. Since the configuration of the ECUs 8a and 8b is the same as the configuration of the ECU 8 shown in FIG. The ECU aggregation device 9 includes a shared CAN transceiver 91 in addition to the two ECUs 8 a and 8 b, and the CAN transceiver 91 is connected to a CAN bus 92. The signals output from the output terminals Txa and Txb of the CAN controllers 82 and 82 of the ECUs 8 a and 8 b are both input to the CAN transceiver 91. Signals received by the CAN transceiver 91 are input to the input terminals Rxa and Rxb of the CAN controllers 82 and 82 of the ECUs 8a and 8b.

  FIG. 12 is a time chart showing an example of signal levels at the input / output terminals Txa, Rxa, Txb, and Rxb of the CAN controllers 82 and 82 in the configuration example of FIG. In FIG. 12, the horizontal axis represents time, and the vertical axis represents signal levels at the input / output terminals Txa, Rxa, Txb, and Rxb. The signal level in the CAN bus 92 is shown in the lower part. When the ECU 8a attempts to transmit a CAN message, the signal level of the output terminal Txa of the CAN controller 82 of the ECU 8a changes, and the signal level in the CAN bus 92 is changed by the CAN transceiver 91 as shown in FIG. Is sent. Since the CAN transceiver 91 monitors the CAN bus 92 and inputs the received signals to the input terminals Rxa and Rxb of the CAN controllers 82 and 82, as shown in FIG. 12, a waveform indicating a CAN message being transmitted at the output terminal Txa. Matches. Then, since the signal level at its output terminal Txa and the signal level at the input terminal Rxa match during the output of the CAN message, the ECU 8a recognizes that it has obtained the transmission right.

  An ACK signal is transmitted from the ECU 8b that has received the CAN message and other ECUs connected to the CAN bus 92. FIG. 12 shows that the ACK signal is output from the output terminal Txb of the CAN controller 82 of the ECU 8b. As a result, an ACK signal is transmitted to the CAN bus 92 via the CAN transceiver 91, and the ACK signal is also input to the input terminal Rxa of the CAN controller of the ECU 8a that has obtained the right to transmit the CAN message.

  In this case, if no communication device other than the ECU aggregation device 9 is connected to the CAN bus 92, the ECU 8a should determine that communication with another communication device is not established without receiving an ACK signal. It is. However, as described above, by sharing the CAN transceiver 91, it is determined that the ACK signal is always transmitted from the ECU 8b regardless of the presence / absence of other communication devices, and communication is always established. As a result, although all communication devices connected to the CAN bus 92 can shift to the sleep state, a problem such as failure to shift to the sleep state as a whole occurs. If this is executed as it is, there may be a problem.

  Such a problem is not limited to the CAN network. When considering a configuration in which a transceiver is shared by a plurality of network controllers, there is a possibility that signal input / output is completed inside the transceiver and signals such as messages or response signals to be received from the outside cannot be received correctly. This problem can also occur with other protocols and protocols that will be used in the future.

  SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and a communication device aggregating apparatus capable of conserving space by consolidating a plurality of communication devices in a limited space and reducing the number of wires in a communication system. Therefore, an object of the present invention is to provide a communication circuit for realizing communication in accordance with the conventional communication protocol, a communication device including the communication circuit, a communication system including the communication circuit, and a communication device aggregation device.

  The communication circuit according to the first invention outputs a data signal from the output terminal to be transmitted to the communication line, inputs a data signal received from the communication line at the input terminal, and receives a data signal as a response signal A plurality of communication control means configured to output from the output terminal, a data signal or response signal output from the communication control means is transmitted to the communication line, and a data signal or response signal is received from the communication line A communication circuit connected to a transceiver configured to give to the communication control means, a plurality of output connection terminals connected to the output terminals of the plurality of communication control means, A plurality of input connection terminals connected to the input terminals of the plurality of communication control means; a transmission terminal for outputting a logical product of signals received at the output connection terminals to the transceiver; and the transceiver Or A receiving terminal for receiving a given signal and a response timing receiving terminal for receiving a timing signal indicating an output timing of the response signal, and a signal input by the receiving terminal is connected to the plurality of input terminals by the input connecting terminal. It is configured to be input by an input terminal of a communication control means, and when a data signal is received by any of the plurality of output connection terminals, while the timing signal is received by the response timing receiving terminal, A response signal from the communication control means received by a plurality of output connection terminals is configured not to be output from the transmission terminal.

  A communication circuit according to a second aspect of the invention relates to a selector that selects and outputs either a signal received by the output connection terminal or a base signal in correspondence with each of the plurality of output connection terminals, and another output A register that holds whether or not a data signal is received by the other output connection terminal depending on whether or not a signal received from the connection terminal matches a signal input by the reception terminal, and the selector includes: The base signal is output when the register holds that the data signal has been received by another output connection terminal, and when the timing signal is being received by the response timing reception terminal. And the logical product of the output signals from the selectors connected to the output connection terminals is input to the transmission terminal. And wherein the Rukoto.

  The communication device according to the third aspect of the invention outputs a data signal from the output terminal to be transmitted to the communication line, inputs a data signal received from the communication line at the input terminal, and receives a data signal when the data signal is input. A plurality of communication control means configured to output from the output terminal, a communication circuit according to claim 1 or 2 connected to the plurality of communication control means, and a response signal from the communication control means Generating means for generating a timing signal indicating the output timing, and the timing signal generated by the generating means is input to a response timing receiving terminal of the communication circuit.

  In the communication system according to the fourth aspect of the invention, a data signal is output from the output terminal to be transmitted to the communication line, a data signal received from the communication line is input at the input terminal, and a response signal is input when the data signal is input. A plurality of communication devices each having communication control means configured to output from the output terminal, a transceiver for realizing transmission of a signal to the communication line and reception of a signal from the communication line, A communication circuit including the communication device and the communication circuit according to claim 1 connected to the transceiver, wherein a response signal output from any one of the plurality of communication devices is controlled. A generating unit configured to generate a timing signal indicating output timing, and configured to input the timing signal generated by the generating unit to a response timing receiving terminal of the communication circuit; To.

  The communication equipment aggregating apparatus according to the fifth aspect of the invention outputs a data signal from an output terminal to be transmitted to a communication line, inputs a data signal received from the communication line at an input terminal, and inputs a data signal. A communication device aggregating apparatus for aggregating a plurality of communication devices each having communication control means configured to output a response signal from the output terminal, wherein the signal is transmitted to the communication line and the signal from the communication line The communication circuit according to claim 1 or 2 connected to the transmission / reception unit that realizes reception, a communication control unit of the plurality of communication devices, and the transmission / reception unit, and any of the plurality of communication devices A timing signal indicating the output timing of the response signal output from the communication control means is input to the response timing receiver of the communication circuit.

  According to a sixth aspect of the present invention, there is provided the communication device aggregation device according to the fifth aspect, wherein the communication line is a CAN bus and the transmission / reception unit is a CAN transceiver.

  In the first invention and the fourth invention, the communication circuit is connected to communication control means of a plurality of communication devices and a transceiver shared by the plurality of communication control means. The communication control means includes an output terminal for outputting a signal transmitted via a transceiver (transceiver) and an input terminal for inputting a signal received by the transceiver. The communication circuit receives both the data signal output from the output terminals of the plurality of communication control means or the response signal through the output connection terminal. The logical product of a signal such as a data signal received by the output connection terminal is transmitted from the transmission terminal to the outside. A signal received from the outside via the transceiver is input through a receiving terminal, and input to the plurality of communication control means through a plurality of input connection terminals. When a plurality of communication control means connected to the communication circuit are each configured to output a response signal from the output terminal at a predetermined timing based on the regulations when a signal is input from the input connection terminal of the communication circuit. The communication circuit accepts this via the output connection terminal.

  A timing signal indicating the output timing of the response signal is received by the response timing receiving terminal. The timing signal is configured to be generated by any one of a plurality of communication control means or other specific means. When the communication circuit receives a data signal from any one of the plurality of communication control means to be connected through the output connection terminal, when the timing signal is received from the response timing reception terminal, Even if the response signal is received by the output connection terminal, it is not transmitted from the transmission terminal to the outside.

  Thereby, even if another communication control means of the plurality of communication control means outputs a response signal to the data signal output from any of the plurality of communication control means connected to the communication circuit, The response signal is not input to the communication control means of the data signal transmission source. Instead, the response signal received from the outside by the transceiver is input from the reception terminal of the communication circuit, and is input to each communication control means. When none of the plurality of communication control means connected to the communication circuit outputs a data signal, the logical product of the response signals output from each communication control means is output to the outside, Communication can be realized without hindrance according to the conventional communication protocol, such as correctly determining whether communication with the communication control means is possible.

  In the second invention, in the first invention, when a data signal is output from any of the plurality of communication control means connected to the communication circuit, the other communication control means among the plurality of communication control means outputs The response signal is not input to the communication control means that is the transmission source of the data signal, but this configuration is a combination of a selector and a register that are included corresponding to each of the plurality of output connection terminals. Realized. The selector selects either a data signal or response signal from the output connection terminal and a constant output voltage, that is, a base signal, and the register holds whether the data signal is received from another output connection terminal . When a data signal is accepted from another output connection terminal, the base signal is selected and output by the selector at the output timing of the response signal, so that the response signal is not output from the transmission terminal to the transceiver .

  In the third invention, a plurality of data signals are output from the output terminal to be transmitted to the communication line, a data signal received from the communication line is input at the input terminal, and a response signal to the data signal is output from the output terminal. The communication control means and the communication circuit of the first invention are provided, and the input / output terminal of the communication control means is connected to the input / output connection terminal of the communication circuit. Furthermore, a generating means for generating a timing signal indicating a timing at which the communication control means outputs a response signal is provided, and the generated timing signal is input to a response timing receiving terminal of the communication circuit. .

  Similarly, when sharing a transmitter / receiver with another communication device including a communication control unit, the input / output terminal of the communication control unit of the other communication device is connected to the communication circuit provided by itself and the communication circuit is shared. Connect to the transceiver. As a result, it is possible to correctly receive a response signal from the outside of the transmitter / receiver without communicating response signals between a plurality of communication devices sharing the transmitter / receiver, and communicate with other communication devices using the response signal. It is possible to realize communication without hindrance according to the conventional communication protocol, such as correctly determining whether or not it is possible.

  In the fifth invention, when collecting and accommodating a plurality of communication devices having an input / output terminal for inputting and outputting signals to be transmitted and received and having a communication control means for transmitting a response signal to the data signal, A communication circuit of one invention is provided, and a transmission / reception unit (transceiver) is shared by the plurality of communication devices via the communication circuit. Furthermore, a generation means for generating a timing signal indicating a timing at which a response signal is output from any of the plurality of communication devices is provided, and the generated timing signal is input to a response timing reception terminal of the communication circuit. Configured as follows.

  As a result, transmission / reception can be realized by sharing the transmission / reception unit among the plurality of communication devices, and other than the transmission / reception unit from the outside without transmitting / receiving response signals only between the communication devices sharing the transmission / reception unit. It is possible to correctly receive a response signal from the communication device, and to correctly determine whether communication is possible by using the response signal, thereby realizing communication without hindrance according to the conventional communication protocol.

  In the sixth invention, the CAN controller based on the CAN protocol is configured to output the ACK signal as a response signal at the end of the data signal while inputting the data signal. Whether or not communication is possible based on the communication protocol by inputting a response signal from the CAN controller of another communication device connected to the CAN bus outside the CAN transceiver without inputting / outputting an ACK signal only between the CAN controllers Can be determined correctly.

  In the first to sixth inventions, the communication circuit is realized by an IC having each element and terminal, or a substrate on which the element and terminal are mounted. The communication device incorporates the communication circuit, and other circuits such as a microcomputer, connector It is realized as equipment including

  According to the present invention, when a plurality of communication devices are concentrated in a limited space to save space and a communication device aggregation device for reducing the number of communication lines in the communication system is to be realized, By adopting a configuration in which the transceiver is shared using the communication circuit of the invention, communication can be realized in each communication control means without any trouble according to the conventional communication protocol.

  Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof. In the first and second embodiments described below, an ECU aggregating apparatus that aggregates ECUs including a microcomputer with a built-in network controller as a communication device will be described as an example. Hereinafter, the network will be described as a CAN network.

(Embodiment 1)
FIG. 1 is a perspective view schematically showing an external appearance of the ECU aggregation device according to the first embodiment. 1 and 2 in FIG. 6 are ECUs which are communication devices, ECU1 is an ECU provided with a communication circuit according to the present invention, and ECU2 is another ECU that is aggregated together with ECU1. Moreover, 3 in FIG. 1 is an ECU aggregating apparatus that aggregates ECUs 1, 2, 2,. The ECU aggregation device 3 includes a substantially rectangular parallelepiped casing 31. On one surface of the casing 31, insertion ports 32, 32,... For inserting ECUs 1, 2, 2,. A harness 33 is attached to the surface opposite to the surface where the insertion ports 32, 32,... Are formed. The harness 33 receives ECU messages sent from the ECUs 1, 2, 2,... And the power lines for supplying power to the ECUs 1, 2, 2,. A CAN bus 35 for transmission is included.

  The ECUs 1 and 2 are configured by forming parts on a substrate. A connector with another component is formed on one side of the board, and the ECU 1 and 2 are inserted into the insertion ports 32 and 32 from the connector side so that the connector is connected to the housing 31 of the ECU aggregating apparatus 3. It is comprised so that it may fit in the receptacle provided inside. The ECUs 1 and 2 may be housed in a substantially flat rectangular case as shown in FIG.

  FIG. 2 is a configuration diagram illustrating a configuration of the ECU aggregation device 3 according to the first embodiment. In addition, the block diagram of FIG. 2 shows a configuration in a state where the ECUs 1 and 2 are accommodated.

  The ECU aggregation device 3 includes a CAN transceiver 34 inside the housing 31, and the CAN transceiver 34 is connected to a CAN bus 35 included in the harness 33. The CAN transceiver 34 realizes transmission / reception of signals on the CAN bus 35 in the physical layer.

  The ECU 2 includes a microcomputer 20 including a CPU 21 and a CAN controller 22. The microcomputer 20 is an existing device used as a general-purpose microcomputer compatible with CAN communication. The CPU 21 reads an OS corresponding to OSEK / VDX having the software configuration shown in FIG. 10 from the built-in ROM and performs processing. The microcomputer 20 has an output terminal Tx and an input terminal Rx from the CAN controller 22 as interfaces. The CAN controller 22 outputs a message signal to be transmitted in response to an instruction from the CPU 21 from the output terminal Tx, receives a signal input at the input terminal Rx, and notifies the CPU 21 of the message represented by the signal. It should be noted that the microcomputer 20, which is a general-purpose microcomputer for CAN communication, needs to connect the CAN controller 22 to the CAN bus 35 via the CAN transceiver 34 in order to actually send and receive messages to the CAN bus 35. It is configured.

  The ECU 1 includes a shared circuit 10 including a CPU 11, a CAN controller 12, and a communication circuit 13. The shared circuit 10 is configured by, for example, an ASIC (Application Specific Integrated Circuit). The CPU 11 and the CAN controller 12 are components having the same functions as the CPU 21 and the CAN controller 22 included in the microcomputer 20 of the ECU 2. The CPU 11 performs processing corresponding to OSEK / VDX in the same manner as the CPU 21. The shared circuit 10 may further include a component for performing processing unique to the ECU 1.

  Note that the CAN controller 12 included in the shared circuit 10 of the ECU 1 can individually extract the output of the ACK signal, and is provided with an ACK timing output terminal ACK_O that outputs a timing signal indicating a timing at which the ACK signal is output. ing.

  The communication circuit 13 included in the shared circuit 10 includes a plurality of connection terminals Txa, Rxa, Txb, and Rxb, a transmission terminal Txc, a reception terminal Rx, and an ACK timing terminal ACK for inputting a timing signal of the ACK signal. .

  The output terminal Tx of the CAN controller 12 of the ECU 1 is connected to the connection terminal Txa of the communication circuit 13, and the input terminal Rx of the CAN controller 12 of the ECU 1 is connected to the connection terminal Txb. The output terminal Tx of the CAN controller 22 of the ECU 2 is connected to the connection terminal Txb, and the input terminal Rx of the CAN controller 22 of the ECU 2 is connected to the connection terminal Rxb. The transmission terminal Txc of the communication circuit 13 is configured to output a signal to be transmitted to the CAN transceiver 34, and the reception terminal Rxc is configured to input a signal received by the CAN transceiver 34. An ACK timing output terminal ACK_O of the CAN controller 12 of the ECU 1 is connected to the ACK timing terminal ACK.

  FIG. 3 is a circuit diagram showing details of the communication circuit 13 according to the first embodiment. The communication circuit 13 includes multiplexers (MUX) 301a, 302a, 301b, and 302b, D-flip flops (FF) 303a and 303b, AND gates 304a and 304b, XOR gates 305 and 306, and an AND gate 307, respectively. Configured.

  Signals from the output connection terminals Txa and Txb connected to the output terminals Tx and Tx of the CAN controllers 12 and 22 are configured to be input to the S1 terminals of the multiplexers 301a, 302a, 301b, and 302b. The signals from the output connection terminals Txa and Txb are ANDed when no timing signal is input from the ACK timing terminal ACK by the multiplexers 301a, 302a, 301b, and 302b, that is, when it is not the timing at which the ACK signal is output. The signal is output from the transmission terminal Txc via the gate 307.

  A signal output from the transmission terminal Txc of the communication circuit 13 is transmitted from the CAN transceiver 34 to the CAN bus 35. Furthermore, since the CAN transceiver 34 monitors and receives the CAN bus 35, the signal transmitted to the CAN bus 35 by arbitration is input to the receiving terminal Rxc of the communication circuit 13, and the CAN controllers 12 and 22 of the ECUs 1 and 2 receive the signals. The input terminals Rx and Rx are configured to be input respectively. The CAN controllers 12 and 22 continue to output signals only when the signal level at the output terminal Tx matches the signal level at the input terminal Rx.

  A signal input from the reception terminal Rxc of the communication circuit 13 is also input to XOR gates 305 and 306 to which signals from the output connection terminals Txa and Txb are input, respectively. Accordingly, for example, only when one of the signal levels at the output connection terminals Txb and Rxc is at the Low level, that is, the signal levels do not match and the CAN controller 22 of the partner sharing the CAN transceiver 34 transmits. Only when not in the middle, the high level is input to the AND gate 304a. By holding the output of the AND gate 304a in the D-flip flop 303a, when the CAN controller 22 is transmitting a CAN message, the High level input to the multiplexer 301a is selected at the time of ACK output timing. The ACK signal (Low level) is not output from the transmission terminal Txc. The signal from the output connection terminal Txb is symmetrical with the configuration of the signal from the output connection terminal Txa.

  With such a configuration, when one of the ECUs 1 and 2 transmits a CAN message and the corresponding signal is received by any of the output connection terminals Txa and Txb, the output timing of the ACK signal is reached. In addition, the ACK signal received by one of the output connection terminals Txa and Txb is not output from the transmission terminal Txc, and the ACK signal is not transmitted from the ECU integrated device 3.

  If neither of the ECUs 1 and 2 transmits a CAN message and the corresponding signal is not received by any of the output connection terminals Txa and Txb, the output connection terminal is used when the ACK output timing is reached. An ACK signal accepted by both Txa and Txb is output from the transmission terminal Txc via the AND gate 307, and the ACK signal is transmitted from the ECU integration device 3.

  FIG. 4 is a time chart illustrating an example of signal levels at the input / output connection terminals Txa, Rxa, Txb, Rxb, the transmission / reception terminals Txc, Rxc, and the ACK timing terminal ACK of the communication circuit 13 according to the first embodiment. In FIG. 4, the horizontal axis represents time, and the vertical axis represents signal levels at the terminals ACK, Txa, Rxa, Txb, Rxb, Txc, and Rxc. The signal level at Rxc is the signal level at CAN bus 35.

  In the example illustrated in FIG. 4, the ECU 1 has acquired the right to transmit a CAN message. Since the ECU 1 transmits a CAN message by the CPU 11, the signal level of the output terminal Tx of the CAN controller 12 of the ECU 1 changes, and as shown in FIG. 4, the signal level at the output connection terminal Txa of the communication circuit 13 is the level of the CAN message. Waveform is shown. On the other hand, since the ECU 2 is the side that receives the CAN message, the signal level at the output connection terminal Txb of the communication circuit 13 connected to the output terminal Tx of the CAN controller 22 of the ECU 2 remains High. Inside the communication circuit 13, signals input from the output connection terminals Txa and Txb are output from the transmission terminal Txc via the AND gate 307 (arrow 1 in FIG. 4). In the case shown in FIG. 4, if one of the AND gates 307 is at a low level, a low level is output. Therefore, the transmission terminal Txc outputs a signal input from the output connection terminal Txa.

  A signal input from the transmission terminal Txc of the communication circuit 13 to the CAN transceiver 34 is transmitted to the CAN bus 35. Since the CAN transceiver 34 receives the signal, the signal level at the reception terminal Rxc of the communication circuit 13 matches the signal level at the transmission terminal Txc. A signal input from the reception terminal Rxc is also input to input connection terminals Rxa and Rxb connected to the CAN controllers 12 and 22 of the ECUs 1 and 2 (arrow 2 in FIG. 4).

  In response to the CAN message transmitted in this way, the ECU 2 that has received the CAN message returns an ACK signal. Therefore, at the output timing of the ACK signal, the ACK signal is input to the output connection terminal Txb of the communication circuit 13 to which the output terminal Tx of the CAN controller 22 of the ECU 2 is connected. However, in the communication circuit 13, the output connection terminal Txa is based on the signal level at the output connection terminal Txa to which the output terminal Tx of the CAN controller 12 of the ECU 1 is connected and the signal level at the reception terminal Rxc (CAN bus 35). It memorizes that the ECU 1 on the side was sending a CAN message. In this case, the communication circuit 13 is selected by the MUXs 301b and 302b so that the signal input from the output connection terminal Txb is not output from the transmission terminal Txc via the AND gate 307 (in FIG. 4, arrow 3 And dashed line).

  In response to the CAN message transmitted by the ECU 1, an ACK signal transmitted from the other communication device connected to the CAN bus 35 to the CAN bus 35 is input at the reception terminal Rxc of the communication circuit 13 and input connection terminal Rxa. , Rxb are output to CAN controllers 12 and 22 of ECUs 1 and 2 (arrow 4 in FIG. 4). Thereby, ECU1 which transmitted the CAN message can receive the response signal with respect to the CAN message which self transmitted normally from the outside, and can judge the establishment / non-establishment of communication correctly.

  FIG. 5 is a time chart illustrating another example of signal levels at input / output connection terminals Txa, Rxa, Txb, Rxb, transmission / reception terminals Txc, Rxc, and ACK timing terminal ACK of the communication circuit 13 according to the first embodiment. . In FIG. 5, the horizontal axis represents time, and the vertical axis represents the signal level at each terminal ACK, Txa, Rxa, Txb, Rxb, Txc, Rxc. The signal level at Rxc is the signal level at CAN bus 35.

  In the example illustrated in FIG. 5, it is assumed that both ECUs 1 and 2 sharing the CAN transceiver 34 are sides that receive a CAN message. Since both the ECUs 1 and 2 are on the side that receives the CAN message, the signal levels at the output connection terminals Txa and Txb of the communication circuit 13 connected to the output terminals Tx of the CAN controllers 12 and 22 of the ECUs 1 and 2 are both. It remains High. On the other hand, a CAN message is transmitted to the CAN bus 35 by another communication device, and a signal input from the reception terminal Rxc is also input to the input connection terminals Rxa and Rxb.

  The CAN controllers 12 and 22 of the ECUs 1 and 2 that input the CAN message signals input from the input connection terminals Rxa and Rxb at the input terminals Rx and Rx return an ACK signal. Therefore, at the output timing of the ACK signal, the ACK signal is input to the output connection terminals Txa and Txb of the communication circuit 13 to which the output terminals Tx and Tx of the CAN controllers 12 and 22 of the ECUs 1 and 2 are connected. . Since the communication circuit 13 holds that the CAN message signal is not input from either of the output connection terminals Txa and Txb, the ACK signal output from the output connection terminals Txa and Txb is Both are output from the transmission terminal Txc via the AND gate 307 (arrow 5 in FIG. 5).

  As a result, when other communication devices are connected to the CAN bus 35, one of them transmits a CAN message, and both of the ECUs 1 and 2 sharing the CAN transceiver 34 receive the CAN message, The ACK signal transmitted from 2 is normally transmitted from the CAN transceiver 34, and it is possible to correctly determine whether communication has been established or not from an external communication device. Further, in this case, although both of the ECUs 1 and 2 sharing the CAN transceiver 34 are on the side of receiving the CAN message, an ACK signal is not transmitted for the first time when communication is not established. On the other hand, if the ACK signal is returned, the ACK signal is transmitted.

  FIG. 6 is a time chart showing another example of signal levels at input / output connection terminals Txa, Rxa, Txb, Rxb, transmission / reception terminals Txc, Rxc, and ACK timing terminal ACK of the communication circuit 13 according to the first embodiment. .

  In the example shown in FIG. 6, in a situation where no communication device other than the ECU aggregation device 3 is connected to the CAN bus 35, that is, when the communication function is not physically executed, the ECU 1 sends a CAN message. Have the right to send. Since the ECU 1 transmits the CAN message by the CPU 11, the signal level of the output terminal Tx of the CAN controller 12 of the ECU 1 changes, and the signal level at the output connection terminal Txa of the communication circuit 13 indicates the waveform of the CAN message. On the other hand, since the ECU 2 is the side that receives the CAN message, the signal level at the output connection terminal Txb of the communication circuit 13 connected to the output terminal Tx of the CAN controller 22 of the ECU 2 remains High. Therefore, a signal input from the output connection terminal Txa is output from the transmission terminal Txc.

  A signal input from the transmission terminal Txc of the communication circuit 13 to the CAN transceiver 34 is transmitted to the CAN bus 35. Since the CAN transceiver 34 receives the signal, the signal input from the reception terminal Rxc of the communication circuit 13 is input to the input connection terminals Rxa and Rxb connected to the CAN controllers 12 and 22 of the ECUs 1 and 2 in the communication circuit 13. Is also entered.

  Since the ECU 2 receives the CAN message transmitted from the ECU 1, it returns an ACK signal. Therefore, at the output timing of the ACK signal, the ACK signal is input to the output connection terminal Txb of the communication circuit 13 to which the output terminal Tx of the CAN controller 22 of the ECU 2 is connected. However, since the communication circuit 13 holds that the ECU 1 on the output connection terminal Txa side has transmitted the CAN message, even when an ACK signal is input to the output connection terminal Txb, the transmission terminal Txc Are selected by MUX 301b, 302b, etc. (arrow 6 in FIG. 6) so as not to output this ACK signal.

  Therefore, since no ACK signal is transmitted from the ECU aggregation device 3 to the CAN bus 35, if no other communication device is connected to the CAN bus 35, an ACK signal is transmitted to the CAN bus 35 in response to the CAN message transmitted by the ECU 1. Is not sent.

  The CAN transceiver 34 monitors the CAN bus 35 and inputs a signal to the reception Rxc of the communication circuit 13. Since the ACK signal is not transmitted, the ACK signal is not input to any of the input connection terminals Rxa and Rxb of the communication circuit 13 regardless of the output timing of the ACK signal as shown in the uppermost part of FIG. (Arrow 7 in FIG. 6). Therefore, the ACK signal is not input to the input terminals Rx and Rx of the CAN controllers 12 and 22 of the ECUs 1 and 2 regardless of the output timing of the ACK signal. Thereby, since CPU11 of ECU1 which transmitted the CAN message does not receive an ACK signal, it can be judged normally that communication with other communication equipment is not established.

  As shown in FIG. 12, in the configuration in which the CAN transceiver is simply shared by the CAN controller without using the communication circuit 13, although it should be determined that communication with other communication devices is not established, It is determined to be established by receiving an ACK signal from another shared ECU. In this regard, the problem does not occur when the communication circuit 13 of the first embodiment is used.

  As described above, when one of the ECUs 1 and 2 aggregated in the ECU aggregating apparatus 3 transmits a CAN message by the communication circuit 13 provided in the ECU 1, an ACK signal from the other to the CAN message is transmitted to the outside of the CAN transceiver 34. Can be prevented from being sent to. Thus, by integrating the plurality of ECUs 1 and 2 using the communication circuit 13, a plurality of ECUs 1 and 1 can be used while using a microcomputer operating on an OSEK / VDX standard-compliant OS having an OSEK-NM function without any trouble. 2 can share the communication resource (CAN transceiver 34) to realize the ECU concentrating device 3 that saves wires.

  In the first embodiment, the number of ECUs 1 and 2 aggregated by the ECU aggregating apparatus 3 is two. However, the present invention is not limited to this, and several ECUs can be integrated. At this time, the configuration of the communication circuit 13 is such that the number of input / output connection terminals is increased and a set of circuits such as MUX 301a, 301a, 302a, 302b, FF 303a, 303b, MUX 304a, 304b, and XOR gates 305, 306 are associated with the ECU. It is necessary to take measures such as providing as many as

(Embodiment 2)
In the first embodiment, the communication circuit 13 that can prevent the ACK signals from the ECUs 1 and 2 aggregated in the ECU aggregating apparatus 3 from being transmitted outside the CAN transceiver 34 is provided outside the microcomputer 10 in one ECU 1. It was set as the structure provided. On the other hand, in the second embodiment, the communication circuit is provided in advance in the ECU aggregation device.

  FIG. 7 is a configuration diagram illustrating a configuration of the ECU aggregation device according to the second embodiment. Reference numeral 4 in FIG. 7 denotes an ECU aggregation device. The appearance of the ECU aggregation device 4 is the same as that of the ECU aggregation device 3 in the first embodiment shown in FIG. The ECU aggregating apparatus 4 accommodates two ECUs 2 and 2 in an aggregated manner. In addition, the block diagram of FIG. 7 shows a configuration in a state where the ECUs 2 and 2 are accommodated. Since the ECUs 2 and 2 are the same as those in the first embodiment, the same reference numerals are given and detailed descriptions thereof are omitted.

  The ECU aggregation device 4 includes a shared circuit 40 formed of an ASIC inside a housing (not shown) so that when the ECUs 2 and 2 are accommodated, the board of the ECUs 2 and 2 and the shared circuit 40 are connected. Composed. The shared circuit 40 includes a communication circuit 41, a CAN transceiver 43, and an ACK detection circuit 45. The CAN transceiver 43 is connected to a CAN bus 44 included in a harness 42 attached to the casing of the ECU aggregation device 4. Yes. The CAN transceiver 43 implements transmission / reception of signals on the CAN bus 44 in the physical layer.

  The communication circuit 41 includes a plurality of connection terminals Txa, Rxa, Txb, Rxb, a transmission terminal Txc, a reception terminal Rx, and an ACK timing terminal ACK for inputting a timing signal of the ACK signal. Since the internal configuration of the communication circuit 41 is the same as that of the communication circuit 13 in the first embodiment, detailed description thereof is omitted.

  The ACK detection circuit 45 is configured so that a signal from the connection terminal Rxb connected to the input terminal Rx of the CAN controller 22 of any of the ECUs 2 and 2 accommodated in the ECU aggregation device 4 is branched and input. Of course, the signal from the connection terminal Rxa may be branched and input. The ACK detection circuit 45 has a function of detecting a timing at which an ACK signal is output based on a CAN message signal transmitted from the ECU 2 or 2 or an external ECU, and generating a timing signal indicating the timing. The ACK detection circuit 45 includes an ACK timing output terminal ACK_O that inputs the generated timing signal to the ACK timing terminal ACK of the communication circuit 41.

  In the ECU aggregating apparatus 4 configured as described above, when one of the ECUs 2 and 2 aggregated in the ECU aggregating apparatus 4 is transmitted by the communication circuit 41, an ACK signal from the other to the CAN message is transmitted to the CAN transceiver. The fact that it is possible to prevent transmission outside of 43 is the same as in the first embodiment.

  By integrating the plurality of ECUs 2 and 2 using the communication circuit 41, communication is performed by the plurality of ECUs 2 and 2 while using a microcomputer operating on the OSEK / VDX standard-compliant OS having the OSEK-NM function without any trouble. It is possible to realize the ECU aggregation device 4 that shares resources (CAN transceiver 43) to reduce the number of lines. In the second embodiment, a plurality of the ECUs 2 and 2 can be consolidated without changing the internal configuration of the conventional ECUs 2 and 2, and an excellent effect can be obtained.

  In the second embodiment, an ACK detection circuit 45 is provided in the shared circuit 40, and the ACK detection circuit 45 branches and inputs a signal from the connection terminal Rxb (or connection terminal Rxa) of the communication circuit 41, and outputs an ACK signal. The timing signal indicating the timing is generated and input to the ACK timing terminal ACK of the communication circuit 41. However, the present invention is not limited to this, and the output of the ACK signal may be extracted from either of the CAN controllers 22 and 22 of the ECUs 2 and 2 to generate a timing signal and input it to the communication circuit 41.

  The disclosed embodiments should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is a perspective view schematically showing an external appearance of an ECU aggregation device in Embodiment 1. FIG. 1 is a configuration diagram illustrating a configuration of an ECU aggregation device according to a first embodiment. 3 is a circuit diagram illustrating details of a communication circuit according to Embodiment 1. FIG. 4 is a time chart illustrating an example of signal levels at an input / output connection terminal, a transmission / reception terminal, and an ACK timing terminal of the communication circuit according to the first embodiment. 6 is a time chart illustrating another example of signal levels at the input / output connection terminal, the transmission / reception terminal, and the ACK timing terminal of the communication circuit according to the first embodiment. It is a time chart which shows the example of a number level. 6 is a time chart illustrating another example of signal levels at the input / output connection terminal, the transmission / reception terminal, and the ACK timing terminal of the communication circuit according to the first embodiment. 1 is a configuration diagram illustrating a configuration of an ECU aggregation device according to a first embodiment. The block diagram of the communication system which contains several ECU simply is shown. It is a time chart which shows the example of the signal level in the input-output terminal of the CAN controller of a general purpose microcomputer. The software configuration based on OS corresponding to OSEK / VDX is shown. It is a block diagram which shows the structure in case a CAN transceiver is simply shared by two ECUs. 12 is a time chart illustrating an example of signal levels at input / output terminals of a CAN controller in the configuration example of FIG. 11.

Explanation of symbols

1 ECU (communication device)
12, 22 CAN controller (communication control means)
13 Communication circuit Txa, Txb Connection terminal (Output connection terminal)
Rxa, Rxb connection terminal (input connection terminal)
Txc transmission terminal Rxc reception terminal ACK_O ACK output terminal (generation means)
ACK ACK timing terminal (response timing reception terminal)
307 AND gate 2 ECU (communication equipment)
3 ECU aggregation device (communication equipment aggregation device)
34 CAN transceiver (transceiver)
35 CAN bus (communication line)
4 ECU aggregation device (communication equipment aggregation device)
41 Communication circuit 43 CAN transceiver (transceiver)
44 CAN bus (communication line)
45 ACK detection circuit (generation means)

Claims (6)

A data signal is output from the output terminal to be transmitted to the communication line, a data signal received from the communication line is input at the input terminal, and a response signal is output from the output terminal when the data signal is input. A plurality of configured communication control means and a data signal or response signal output from the communication control means are transmitted to the communication line, and the data signal or response signal is received from the communication line and applied to the communication control means. A communication circuit connected to a configured transceiver,
A plurality of output connection terminals connected to the output terminals of the plurality of communication control means;
A plurality of input connection terminals connected to the input terminals of the plurality of communication control means;
A transmission terminal for outputting a logical product of signals received at the output connection terminal to the transceiver; and
A receiving terminal for inputting a signal given from the transceiver;
A response timing receiving terminal for receiving a timing signal indicating an output timing of the response signal;
The signal input by the receiving terminal is configured to be input by input terminals of the plurality of communication control means by the input connection terminal,
When a data signal is received by any one of the plurality of output connection terminals, a response signal from the communication control unit is received by the plurality of output connection terminals while the timing signal is received by the response timing reception terminal. Is configured so as not to be output from the transmission terminal. Corresponding to each of the plurality of output connection terminals,
A selector that selects and outputs either a signal received by the output connection terminal or a base signal;
A register that holds whether or not a data signal is received by the other output connection terminal depending on whether or not a signal received from the other output connection terminal matches a signal input by the reception terminal;
The selector is
The base signal is output when the register holds that the data signal has been received by another output connection terminal, and when the timing signal is being received by the response timing reception terminal. And
The communication circuit according to claim 1, wherein a logical product of output signals from the selector connected to each output connection terminal is input to the transmission terminal. A data signal is output from the output terminal to be transmitted to the communication line, a data signal received from the communication line is input at the input terminal, and a response signal is output from the output terminal when the data signal is input. A plurality of configured communication control means;
The communication circuit according to claim 1 or 2, connected to the plurality of communication control means,
Generating means for generating a timing signal indicating a timing at which a response signal is output from the communication control means,
A communication apparatus configured to input a timing signal generated by the generating means to a response timing receiving terminal of the communication circuit. A data signal is output from the output terminal to be transmitted to the communication line, a data signal received from the communication line is input at the input terminal, and a response signal is output from the output terminal when the data signal is input. A plurality of communication devices each having a communication control means configured;
A transceiver that realizes transmission of signals to the communication line and reception of signals from the communication line;
A communication system comprising: the communication circuit according to claim 1 or 2 connected to the plurality of communication devices and a transceiver;
A generating unit that generates a timing signal indicating an output timing of a response signal output from any one of the plurality of communication devices;
A communication system, wherein the timing signal generated by the generating means is input to a response timing receiving terminal of the communication circuit. A data signal is output from the output terminal to be transmitted to the communication line, a data signal received from the communication line is input at the input terminal, and a response signal is output from the output terminal when the data signal is input. A communication device aggregation device that aggregates a plurality of communication devices each having a communication control means configured,
A transmission / reception unit that realizes transmission of a signal to a communication line and reception of a signal from the communication line;
The communication control means of the plurality of communication devices, and the communication circuit according to claim 1 connected to the transmission / reception unit,
A communication device, wherein a timing signal indicating an output timing of a response signal output from any one of the plurality of communication devices is input to a response timing receiver of the communication circuit. Aggregator. The communication device aggregation apparatus according to claim 5, wherein the communication line is a CAN (Controller Area Network) bus, and the transmission / reception unit is a CAN transceiver.

Images