JP5708165B2 - In-vehicle communication device - Google Patents

Description

  The present invention relates to an in-vehicle communication device.

  In recent years, many safety and comfort functions are installed in automobiles, and ECUs (Electronic Control Units) that control these individual controls are connected to each other through an in-vehicle network for cooperative operation. A typical example of such an in-vehicle network is a CAN (Controller Area Network), which is widely used as a serial communication network (Patent Document 1). Thus, when controlling in cooperation with each ECU in serial communication, a control application in one ECU needs to receive a control message (data) from another ECU via a serial communication bus. The ECU on the side stores the received message in a buffer called a message box, reads it out appropriately, and uses the message in a predetermined application.

JP 2010-245794 A

  Generally, when a message (received data) is stored in a message box, the message is stored in the leading end of a free area of the message box, and when reading out a message stored in the message box, the leading end of the message box The messages are searched from to the end area, and the messages obtained by the search are read in order.

  In this case, a new message may be stored in the message box while the message is retrieved and read from the message box. That is, the area (tip area) of the message that has already been read becomes an empty area, and a new message is stored in the leading area. As a result, there may be a difference in order between the transmission order of messages transmitted from the ECU on the transmitting side and the reading order in which messages are read out by the EUC on the receiving side.

Specifically, in the situation shown in FIG. 9, an order shift occurs between the message transmission order and the reading order.
First, reading of a message starts (state 1B) in a message box (state 1A) in which two messages 5M and 6M are stored in order from the front end area of the message box. When reading of the message starts, the message is searched from the front end area to the end end area of the message box, and the messages obtained by the search are read in order. Therefore, the message 5M stored in the tip area of the message box is read first. As a result, the leading end area of the message box becomes an empty area, and then the message 6M is read (state 1C).
If a new message 7M or 8M is transmitted to the message box while an interruption process occurs in the receiving ECU during the reading of the message 6M and the reading of the message 6M is delayed, the messages 7M and 8M Are stored in order from the leading end of the empty area of the message box. That is, while the reading of the message 6M is delayed due to the interrupt process, the message 7M is stored in the tip area, and the message 8M is stored in the area immediately after the message 6M (state 1D). When the interrupt process is completed, the continuation of the message 6M is read, and immediately after the reading of the message 6M is completed, reading of the message 8M in the next lined area is started (state 1E). When the reading of the message 8M is completed, the next storage area is an empty area, so an unread message is searched and the message 7M stored in the front end area is read (state 1F).
As a result, between the transmission order of messages transmitted from the ECU on the transmission side (5M → 6M → 7M → 8M) and the reception order (5M → 6M → 8M → 7M) for reading out the message by the EUC on the reception side, Deviation of order occurs.
Therefore, as a result of the reading order of the messages being different from the transmission order on the transmission side, there is a risk of hindering control in the ECU. Therefore, it is necessary to use it on the premise that the message reading order and the sending order are different, which is inconvenient.

  An object of the present invention is to provide an in-vehicle communication device with high communication efficiency by preventing a shift in order between a transmission order of messages transmitted via a communication bus and a reading order for reading out transmitted messages. is there.

Means for Solving the Problems and Effects of the Invention

The in-vehicle communication device of the present invention has the following configuration.
Have a message box for storing a message is received data, when reading the message from the message box toward the distal region of the message storage area of the message box termination region retrieves messages, in order from the message obtained by the search In an in-vehicle communication device with multiple nodes to be read out,
The node in the message storage area output, and a distal region information of the distal region, and termination region information indicating the end region, the storage area information indicating the storage area storing the message just before, the message just before Output area information indicating the output area, and status management means for managing,
State management means
As the writing area for writing a new message, if the storage area and the terminal area are the same, specify the tip area, and if the storage area and the terminal area are not the same, specify the area immediately after the storage area,
If the output area and the end area are the same as the read area for reading a new message, specify the tip area. If the output area and the end area are not the same, specify the area immediately after the output area .
The state management means instructs the reading of the message stored in the message storage area by determining the reading time zone,
While an interrupt process occurs during the reading of a message in the reading time period and the reading process is delayed, a writing process to a new message box is performed .

If the storage area in which the message is stored immediately before is not the termination area, the area immediately after the storage area is designated as the reception data write area. Similarly, if the output area where the message was output immediately before is not the termination area, the area immediately after the output area is designated as the reception data reading area.
Therefore, if the storage area or the output area is not the termination area, it is possible to specify the writing and reading of received data in order from the leading edge area to the terminating area of the message box.
Further, if the storage area in which the message is stored immediately before or the output area in which the message is output immediately before is the termination area, the leading edge area is designated as an area for writing or reading received data. Therefore, even if the reception data is stored in the termination area or the reception data is read from the termination area, the front end area is again designated as the reception data writing area or the reading area. Therefore, it is possible to specify writing and reading of received data in order from the front end area to the end end area of the message box again.
Therefore, it is possible to read the received data in the transmission order of the received data transmitted via the communication bus.

  In the in-vehicle communication device of the present invention, when the message is newly written to or read from the designated write area or read area, the state management means stores the storage area information or the output area information. Update means for updating to the write area or the read area can be provided.

When a message is written to the specified area (write area) or when a message is read from the specified area (read area), the storage area information or message indicating the area where the message was stored immediately before is output. The output area information indicating the completed area is updated.
That is, when a message is newly written or read, the area where the message is stored immediately before or the area where the message is output immediately before is changed. Therefore, by updating the storage area information in the information indicating the writing area and the output area information in the information indicating the reading area, even if a plurality of messages are transmitted, according to the transmission order transmitted via the communication bus, Data can be read out.

  The message storage area is composed of a plurality of continuous unit areas, and the front end area information, the end area information, the storage area information, and the output area information are stored in the unit area together with the message as unit information. Can be.

  For each unit area, four pieces of information that can determine whether the area corresponds to the front end area, the end area, the storage area, or the output area are stored. Therefore, even when a message is written or read with reference to storage area information or output area information, since four pieces of information are stored for each unit area, information searchability is facilitated for each unit area. It is possible to prevent the writing and reading speed from being reduced.

  The state management means determines the reading time zone and instructs the reading of the message stored in the message storage area, and interrupt processing occurs during the reading of the message in the reading time zone and the reading processing is delayed. While writing, a new message box can be written.

As described above, in the conventional in-vehicle communication device, when a new message is transmitted from the transmission side, the reception side stores the messages in order from the leading end side of the empty area of the message box. Therefore, when the receiving side storing the message generates an interrupt process while reading the stored message, and a new message is transmitted while the message reading process is delayed, the message as shown in FIG. In some cases, the transmission order and the reading order are different.
However, in the present invention, since the message is written in the designated writing area, even if a new message is transmitted while the message reading process is delayed due to an interrupt process, the message transmission order And reading order is not disturbed. Further, the received data can be read out in the transmission order of the received data transmitted via the communication bus.

  Further, the state management unit instructs to write a long message in a divided manner, and the divided message can be written / read in the correct order by the storage area information and the output area information. .

When a long message is written in the message box, it is instructed to be written separately.
A conventional in-vehicle communication device needs to embed data indicating the order of divided messages in a message in consideration of the possibility that the writing and reading of messages are not performed in the correct order. Furthermore, in order to confirm whether or not the message has been normally received, it is necessary to transmit a reception confirmation message from the reception side to the transmission side, which makes communication inefficient and causes a heavy processing load on the ECU.
However, since the in-vehicle communication device of the present invention can write and read messages in the correct order based on the storage area information and the output area information, there is no need to embed data indicating the message order, and the efficiency of communication and ECU is improved. be able to.

The block diagram of the vehicle-mounted communication apparatus of this invention. The figure which shows the state by which unit information was accommodated in each unit area | region of a message storage area. A time chart showing the process of writing or reading a message. The figure which shows the unit information of the message box in the time chart of FIG. The flowchart which shows the write-in procedure of an Example. The flowchart which shows the read processing procedure of an Example. The flowchart which shows the write-in procedure of a modification. The flowchart which shows the reading process procedure of a modification. The reference figure which shows the time chart of the conventional communication apparatus.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a block diagram showing an in-vehicle communication device 1 of the present invention. The outline | summary of the vehicle-mounted communication apparatus 1 is demonstrated using FIG.
FIG. 1 is a block diagram of a device (node) connected to a bus that performs communication using CAN, which is a protocol that performs serial communication, that is, a CAN node 2.
The CAN communication data is transmitted from the transmission-side CAN node 3 as a message in a predetermined format. The receiving side CAN node 2 stores the message transmitted from the transmitting side CAN node 3 as received data in the message box 4 which is a buffer for receiving the message, and outputs it.
Since the in-vehicle communication device 1 of the present invention has an order of writing and reading messages transmitted from the transmitting CAN node 3, in the description of the CAN node 2, the CAN node 2 mainly explains reception of messages. The CAN node 2 can not only receive a message but also send it.

The in-vehicle communication device 1 of the present invention manages the state of the message stored in the message box 4 and writes a newly received message in the message box 4 according to the state of the message stored in the message box 4, or A new message stored in the message box 4 is read.
In writing or reading a message, a writing or reading area is designated depending on whether or not the area of the message box 4 in which the message was stored or output immediately before is the terminal area.
Specifically, if the area where the message was stored or output immediately before is the end area, the front end area is designated as the writing or reading area. On the other hand, if it is other than the termination area, the area immediately after the area where the message was stored or output immediately before is designated as the writing or reading area.

  Specifically, the CAN node 2 that transmits and receives a message is the control ECU 2a. The control ECU 2a manages the state of the message box and writes a message in an appropriate area of the message box 4 or reads a message from the appropriate area.

The control ECU 2a has the same structure as a normal microprocessor.
A CPU 5 that performs various operations and information processing, a RAM 6 that is a temporary storage unit as a work area of the CPU 5, a ROM 7 that stores various information, and a non-volatile memory (not shown in FIG. 1).
The ROM 7 stores each application for realizing a function related to operation of each part of the vehicle by the vehicle user. The application is executed by the CPU 5 on a work area corresponding to each application in the RAM 6.
The control ECU 2a is connected to a plurality of other ECUs via the communication bus 8, refers to messages transmitted by the other ECUs, input signals from the outside as necessary, and the like, and executes each application. Controls the operation of controlled devices.

  Specifically, as shown in FIG. 1, the control ECU 2 a includes a message box 4 that stores a message transmitted by the transmission-side ECU 3 a and a state management unit 9 that manages the state of the message box 4. The control ECU 2a uses the state management means 9 to write a message related to its own control process in an appropriate area of the message box 4 or read from the appropriate area, and executes a predetermined control process.

The message box 4 is a buffer for storing a message (received data) transmitted from the transmission side ECU 3a via the serial communication bus 8. In order to store a message to be transmitted, the message box 4 has a message storage area 4a. The message storage area 4a is composed of a plurality of continuous unit areas 4b, and unit information is stored in the unit area 4b together with the message. The unit information is information indicating whether or not certain information exists (present or not). Specifically, this indicates whether or not there is tip area information, end area information, storage area information, or output area information in the predetermined unit area 4b.
Here, the tip area information is information indicating the tip area in the message storage area 4 a of the message box 4. The termination area information is information indicating the termination area in the message storage area 4 a of the message box 4. The storage area information is information indicating a storage area in which the message is stored immediately before in the message storage area 4 a of the message box 4. The output area information is information indicating an output area in which the message is output immediately before in the message storage area 4a of the message box 4.
The “storage area storing the message immediately before” means an area of the message box 4 in which the latest message is stored based on a certain point in time. The “area where the message was output immediately before” means an area where the latest message output from the message box 4 is stored with reference to a certain point in time.

  FIG. 2 is a diagram showing whether or not the tip area information, end area information, storage area information, or output area information exists in the continuous unit area 4b of the message storage area 4a. Specifically, in the message storage area 4a having four consecutive unit areas 4b, for each unit area, the area indicates whether it corresponds to the front end area, the end area, the storage area, or the output area. is there. In the figure, a location storing “1” indicates that there is predetermined information (present), and a location storing “0” indicates that there is no predetermined information (not). In FIG. 2, the message storage area 4a is composed of four unit areas 4b. However, the message storage area 4a can employ any number of unit areas according to the specifications of each ECU.

  The message stored together with the unit information in the unit area 4b is managed by the state management means 9. The state management means 9 performs processing related to writing or reading a message by managing the tip area information, the end area information, the storage area information, and the output area information. Specifically, the state management means 9 designates a writing area for writing a new message in the message box 4 and a reading area for reading a new message. More specifically, if the storage area where the message was stored immediately before and the end area are the same, the front end area is designated as the write area, and if the storage area and the end area are not the same, the storage area immediately after the storage area is specified. Designate the area as a writing area. If the output area and the end area that output the message immediately before are the same, specify the front end area as the read area. If the output area and the end area are not the same, read the area immediately after the output area. Specify as. Then, the state management unit 9 issues a read instruction to write or write a message to the designated write area, or to read a message from the designated read area.

The message reading instruction performed by the state management means 9 is determined by setting a reading time zone for reading the message. On the other hand, the message writing instruction is an occasional writing instruction that is performed whenever a message is transmitted.
In addition, the message reading process according to the reading instruction may be delayed. Specifically, when an interrupt process occurs in the receiving control ECU 2a in the middle of reading a message in the reading time period, the process is delayed. Therefore, if a new message is transmitted while the reading process is delayed due to the interrupt process, the new message is written to the message box as needed by the writing process.
There are also long messages. For a long message that cannot be accommodated entirely in one unit area 4b of the message box, the state management means 9 instructs to write the message separately when writing the message. Each of the divided messages is read by a reading process.

Further, the state management unit 9 includes the update unit 10 illustrated in FIG. 1 to update the writing area for writing the message and the reading area for reading the message. Specifically, when the message is newly written to or read from the writing area or reading area specified by the state management means 9, the updating means 10 stores the storage area information or the output area information in the writing area or the reading area. Update to the reading area.
In other words, if “the storage area where the message was stored immediately before” = “the terminal area”, the storage area information is updated to the information indicating the tip area, and “the storage area where the message was stored immediately before” the “terminal area” In this case, the storage area information is updated to information indicating an area immediately after the area in which the message is stored immediately before. In addition, when “the output area immediately before the message is output” = “the end area”, the output area information is updated to the information indicating the tip area, and “the output area where the message is output immediately before” is not “the end area”. In this case, the output area information is updated to information indicating an area immediately after the area where the message was output immediately before.

On the other hand, some of the messages transmitted from the control ECU 3a on the transmission side include a message transmitted to another control ECU, and the control ECU 2a on the reception side needs to extract only a message necessary for itself. . Therefore, the state management means 9 has a filter function or a mask function that extracts only messages necessary for itself. The filter function is a function for extracting only the message whose ID value included in the message completely matches the value set as the filter (filter value 11) and storing it in the message box 4. The mask function masks some bits of the ID value included in the message (any value corresponding to the masked bit may be any), and the ID value other than the masked value and the value set as a filter (filter This is a function for extracting only messages having the same value 11) and storing them in the message box 4.
The state management means 9 in FIG. 1 sets a filter value 11 for the entire message box 4. Therefore, only messages whose ID value of the transmitted message matches or partially matches the filter value 11 are stored in the message box 4 and output.

  With the above configuration, control is performed to prevent a disorder in order between the transmission order of messages transmitted from the control ECU 3a on the transmission side and the reading order of reading transmitted messages. A conceptual time chart of the processing procedure is shown in FIG.

The process for preventing the disturbance between the message transmission order and the reading order will be described with reference to FIG.
First, messages 0M and 1M are transmitted from the control ECU 3a on the transmission side to the control ECU 2a via the communication bus 8, and stored in the message box 4.
When no message is stored in the message storage area 4 a of the message box 4, the message is stored in the leading end area (0) of the message box 4. Therefore, the message 0M is stored in the tip area (0).
At this time, no message is stored in the message box 4 in the initial state, and the unit information regarding the storage area information is all “0” (no) in all the unit areas 4b. The message 0M is stored in the tip area (0), and then the message 1M is stored in the area (1) next to the area in which the message 0M is stored first, and the unit information of the storage area of the stored area (1) is stored. “1” (present) (state 0).

  Since no message is stored in the message box 4 until the message 0M is stored, all the unit information related to the output area information is “0” in all the unit areas 4b. Therefore, when the written message read time zone is reached, the unit information regarding the output area information is all “0”, so the first reading is performed. That is, the message 0M in the front end area (0) of the message box is read (state 1).

When the reading of the message 0M is completed, the stored message 0M is cleared (state 2). Then, reading of the message 1M stored in the next area (1) is started.
During the reading of the message 1M, an interrupt process occurs in the control ECU 2a on the receiving side, and the reading process of the message 1M is delayed. Then, while the message 1M reading process is delayed, new messages 2M and 3M are transmitted from the transmission-side control ECU 3a to the reception-side control ECU 2a via the communication bus 8, and the message is written whenever necessary. 2M and 3M are written.
The transmitted message 2M is stored in the next area (2) that is unit information “1” of the storage area (state 2-1), and the next message 3M is stored in the message 2M first. Only the unit information of the storage area of the stored area (3) is “1” (state 2-2), and the leading area (0) is set as the next writing area. ) Is specified.
When the interrupt process ends, the message 1M is read again, and when the message 1M is read, the stored message 1M is cleared (state 3). Then, reading of the message 2M newly stored in the next area (2) is started.
When the reading of the message 2M is completed (state 4), the last stored message 3M is read, and when the stored message 3M is cleared, the tip area (0) is designated as the next reading area. Since no message is written in the message box 4 in this area (0), the message reading process is terminated. Therefore, only the unit information related to the storage area and output area of the area (3) is “1” (the unit information related to the storage area and output area of the other area is “0”).

As described above, a message is written from the front end region of the message box 4 toward the end region, and a message is read from the front end region of the message box 4 toward the end region. When the message is written up to the end area, the message is written again from the front end area. Similarly, when a message is read from the front end area to the end end area, the message is read again from the front end area.
Therefore, the control ECU 2a on the reception side can read the messages in the same order as the transmission order of the messages transmitted from the control ECU 3a on the transmission side.

FIG. 4 is a diagram showing unit information 4b of the message box 4 in (state 0) to (state 4) in the time chart of FIG.
In each state, when the unit area 4b of the message box 4 corresponds to “tip area”, “end area”, “storage area”, “output area”, “1”, the unit area 4b of the message box 4 If it does not correspond to the area, “0” is set.
Specifically, in (state 1), in the tip identification information, the region (0) is “1”, and the region (1) to the region (3) are “0”. In the terminal identification information, the area (0) to the area (2) are “0”, and the area (3) is “1”. Since the tip identification information and the termination identification information indicate the tip region and the termination region of the message box 4, the unit information regarding the tip identification information and the termination identification information is the same even in other states.
In (state 1), the storage area information is “0” in the area (0), the area (2), and the area (3), and the area (1) is “1”. In the output area information, the area (0) is “1”, and the areas (1) to (3) are “0”.

  The storage area information in (state 1) is updated so that “1” indicating the storage area information moves toward the terminal area of the message box 4 as a message is newly written to the message box 4. Is done. Further, “1” indicating the output area information is also updated so as to move toward the end area of the message box 4 as a new message is read from the message box 4.

  More specifically, the control processing procedure of the in-vehicle communication device 1 is disclosed in the flowchart of FIG. Specifically, the flowchart of FIG. 5 shows a processing procedure in which storage area information indicating a storage area in which a message is stored immediately before is updated. That is, each time a new message is written, the storage area information indicates a processing procedure that is updated to information indicating an area arranged next to the area indicated by the storage area information. However, when the area indicated by the storage area information is the terminal area, the storage area information is updated to information indicating the tip area.

Messages transmitted from the control ECU 3a on the transmission side are written in the message box 4 in a predetermined order by the following processes S1 to S10.
As a premise, the message storage area 4a of the message box 4 includes the continuous areas (0), (1), (2), and (3) having the area (0) as the front end area and the area (3) as the end area. The following description will be made assuming that the unit region 4b is provided. In the following description, the area (N) indicates an arbitrary unit area 4b in the message storage area 4a, and N indicates a number from 0 to 3. Since the message is not stored in the message box 4 in advance, and the unit information regarding the storage area information in the unit area 4b is all “0” (no), the message will be described below from the tip area (0). To do. The message storage area 4a of the message box 4 is not limited to this, and can be set as appropriate according to the specifications of the control ECU.
First, in S1, the control ECU 2a determines whether the ID value of the message transmitted from the other control ECU 3a matches (or partially matches) the filter value 11. If the filter value 11 of the message box 4 matches the ID value of the transmitted message (S1: YES), the process proceeds to S2, and if the filter value 11 and the message ID value do not match (S1: NO), the message Is not stored in the message box 4, the control is terminated.

If it progresses to S2, control ECU2a will store the message which other control ECU3a transmitted to the area | region (N) of the message storage area 4a, and will progress to S3. Specifically, the message is stored in the area (0) of the message storage area 4a, and the process proceeds to S3.
In S3, it is determined whether the area (N) of the message storage area 4a is a termination area. When the area (N) is the terminal area (area (3)) (S3: YES), the process proceeds to S4, and when the area (N) is not the terminal area (S3: NO), the process proceeds to S9. Specifically, since the area (0) of the message storage area 4a is not the termination area (3), the process proceeds to S9.

  In S9, the update unit 10 updates the unit information related to the storage area information from “1” to “0” in the area (N−1) of the unit area 4b. Further, in the area (N) of the unit area 4b, the unit information related to the storage area information is updated from “0” to “1”. That is, each time a new message is written, the storage area information is updated to information indicating an area arranged next to the area indicated by the storage area information. Then, the process proceeds to S10. However, if the area in which data is written in S2 is the area (N = 0), the area (-1) does not exist, so the updating means 10 relates only the area (N) of the unit area 4b to the storage area information. The unit information is updated from “0” to “1”. Specifically, the update unit 10 updates the unit information related to the storage area information from “0” to “1” in the area (0) of the unit area 4b. Then, the process proceeds to S10.

  In S10, the variable N indicating the position of the unit area 4b of the message storage area 4a is incremented (the variable N is set to N + 1), and the control is terminated. Specifically, N is set to 1 and the control is terminated. Therefore, when a new message is next transmitted from the control ECU 3a on the transmission side, the processes of S1 to S3, S9, and S10 are performed as a variable N (= 1). That is, data is written to the area (1). The same processing is repeated until the variable N becomes 3. When the variable N is 3, since the area (3) is the same as the termination area (3) in S3, the process proceeds to S4.

  In S4, the updating unit 10 updates the unit information related to the storage area information from “1” to “0” in the area (N−1) of the unit area 4b. Further, in the area (N) of the unit area 4b, the unit information related to the storage area information is updated from “0” to “1”. In other words, the storage area information is updated to information indicating the termination area by writing a new message in the termination area. Specifically, the updating unit 10 updates the unit information related to the storage area information from “1” to “0” in the area (2) of the unit area 4b. Further, the updating unit 10 updates the unit information related to the storage area information from “0” to “1” in the area (3) of the unit area 4b. Then, the process proceeds to S5.

  In S5, when a new message is transmitted from the transmission-side control ECU 3a, the control ECU 2a determines whether or not the ID value of the transmitted message matches (or partially matches) the filter value 11. judge. When the filter value 11 of the message box 4 matches the ID value of the transmitted message (S5: YES), the process proceeds to S6, and when the filter value 11 and the message ID value do not match (S5: NO), the process proceeds to S5. The process waits for the transmission of another new message from the control ECU 3a on the transmission side, and determines whether the ID values of the other messages match.

  If it progresses to S6, control ECU2a will store the message which other control ECU3a transmitted to the front-end | tip area | region of the message storage area 4a, and will progress to S7. Specifically, the message is stored in the area (0) of the message storage area 4a, and the process proceeds to S7.

In S7, the updating unit 10 updates the unit information related to the storage area information from “1” to “0” in the terminal area of the unit area 4b. Further, the unit information related to the storage area information is updated from “0” to “1” in the tip area of the unit area 4b. That is, since the area indicated by the storage area information is the terminal area, the storage area information is updated to information indicating the tip area. Specifically, the unit information related to the storage area information is updated from “1” to “0” in the terminal area (N = 3). In the area (N = 0) which is the tip area, the unit information regarding the storage area information is updated from “0” to “1”. Then, the process proceeds to S8.
In S8, the variable N indicating the position of the unit area 4b of the message storage area 4a is set to 1, and the control is terminated.

With the above configuration, messages transmitted from the control ECU 3a on the transmission side are written in the message box 4 in a predetermined order.
On the other hand, the flowchart of FIG. 6 shows a processing procedure in which output area information indicating an output area in which a message was output immediately before is updated. That is, every time a new message is read, the output area information indicates a processing procedure that is updated to information indicating an area arranged next to the area indicated by the output area information. However, when the area indicated by the output area information is the terminal area, the output area information is updated to information indicating the tip area.

Specifically, the message written in the message box 4 is read when the read time zone determined by the state management means 9 is reached. Here, since no message is stored in the message box 4 until the writing process is performed, all the unit information regarding the output area information is “0” in all the unit areas 4b. For this reason, when the written message read time zone is reached, the unit information regarding the output area information is all “0”, so the first reading is performed. In other words, the message is read from the tip area (0) of the message box.
Then, the same processing as the message writing processing is performed. Specifically, the messages written in the message box 4 are read in a predetermined order by the following processes of S11 to S18.
As a premise, the message storage area 4a of the message box 4 includes the continuous areas (0), (1), (2), and (3) having the area (0) as the front end area and the area (3) as the end area. The following description will be made assuming that the unit region 4b is provided. In the following description, the area (M) indicates an arbitrary unit area 4b in the message storage area 4a, and M indicates a number from 0 to 3.

First, in S11, the control ECU 2a reads a message from the area (M) of the message storage area 4a of the message box 4, and proceeds to S12. Specifically, the message is read from the area (0), and the process proceeds to S12.
In S12, it is determined whether the area (M) of the message storage area 4a is a termination area. If the area (M) is a termination area (S12: YES), the process proceeds to S13, and if the area (M) is not a termination area (S12: NO), the process proceeds to S17. Specifically, since the area (0) is not the terminal area (3), the process proceeds to S17.

  In S17, the updating unit 10 updates the unit information related to the output area information from “1” to “0” in the area (M−1) of the unit area 4b. Further, in the area (M) of the unit area 4b, the unit information regarding the output area information is updated from “0” to “1”. That is, each time a new message is read, the output area information is updated to information indicating an area arranged next to the area indicated by the output area information. Then, the process proceeds to S18. However, when the area from which data is read in S11 is the area (M = 0), the area (-1) does not exist, and therefore the updating unit only uses the area (M) of the unit area 4b as the unit for the output area information. The information is updated from “0” to “1”. Specifically, the updating unit 10 updates the unit information related to the output area information from “0” to “1” in the area (0) of the unit area 4b. Then, the process proceeds to S18.

  In S18, the variable N indicating the position of the unit area 4b of the message storage area 4a is incremented (M + 1 is set in the variable M), and the control is terminated. Specifically, M is set to 1 and the control is terminated. Therefore, when the message is stored in the next area immediately after the message is read, the processes of S11 and S12, S17 and S18 are repeated. When the variable M is 3, since the region (3) is the same as the termination region (3) in S12, the process proceeds to S13.

  In S13, the updating unit 10 updates the unit information related to the output area information from “1” to “0” in the area (M−1) of the unit area 4b. Further, in the area (M) of the unit area 4b, the unit information regarding the output area information is updated from “0” to “1”. That is, when a new message is read from the termination area, the output area information is updated to information indicating the termination area. Specifically, the updating unit 10 updates the unit information related to the output area information from “1” to “0” in the area (2) of the unit area 4b. In addition, the update unit 10 updates the unit information related to the output area information from “0” to “1” in the area (3) of the unit area 4b. Then, the process proceeds to S14.

  In S14, if a new message is stored in the front end area (0) of the message box 4, the control ECU 2a reads a new message from the front end area of the message storage area 4a, and then proceeds to S15. Specifically, the message is read from the area (0) of the message storage area 4a, and the process proceeds to S14. If no new message is stored, the process waits for a new message to be stored, reads the stored new message, and proceeds to S15.

In S15, the updating unit 10 updates the unit information related to the output area information from “1” to “0” in the terminal area of the unit area 4b. Further, the unit information related to the output area information is updated from “0” to “1” in the tip area of the unit area 4b. That is, since the area indicated by the output area information is the terminal area, the output area information is updated to information indicating the tip area. Specifically, the unit information regarding the output area information is updated from “1” to “0” in the terminal area (M = 3). Further, in the region (M = 0) which is the tip region, the unit information regarding the output region information is updated from “0” to “1”. Then, the process proceeds to S16.
In S16, the variable M indicating the position of the unit area 4b of the message storage area 4a is set to 1, and the control is terminated.

As described above, the in-vehicle communication device 1 executes a control process with high communication efficiency by preventing the deviation of the order between the transmission order of messages transmitted via the communication bus 8 and the order of reading the transmitted messages. .
In the present embodiment, when the writing or reading process is performed again, the unit information “1” area related to the storage area information or the output area information in each unit area 4b is searched to immediately follow the searched area. This area becomes a writing area or a reading area (however, when the searched area is a terminal area, the tip area becomes a writing area or a reading area).
That is, when the writing process is performed again by transmitting a message from the transmission-side control ECU 3a, or when the reading process is performed again after the end of the reading time period, the storage area information and the output area information are related. By searching for the area “1” in the unit information, the writing area and the reading area can be easily specified, and the search performance is excellent.
In this embodiment, the message is described as messages 0M to 3M. However, even when the message is a long sentence and the message is divided into 0M, 1M, 2M, and 3M and the writing is instructed, the same processing is performed. In this case, there is no need to transmit a reception confirmation message from the reception side to the transmission side in order to confirm whether or not the message has been normally received as in the conventional case, communication is efficient, and the processing of the ECU The load can be reduced.

Next, the modification of the vehicle-mounted communication apparatus 1 of this invention is demonstrated. The same configurations as those in the embodiment are denoted by the same reference numerals as those in the embodiment, the description of the embodiment is used, and the description is omitted. 7 and 8 are flowcharts showing the processing procedure of the modified example, and the modified example will be described with reference to FIGS. 7 and 8.
In the flowchart of the writing process of the embodiment shown in FIG. 5, the unit information regarding the storage area information is updated in S4, S7 and S9.
However, in the modified example of FIG. 7, in S4, S7, and S9, it is determined whether or not the message reading process is completed after updating the unit information regarding the storage area information.
In the flowchart of the reading process of the embodiment shown in FIG. 6, the unit information regarding the output area information is updated in S13, S15, and S17.
However, in the modified example of FIG. 8, in S13, S15, and S17, after updating the unit information regarding the output area information, it is determined whether or not the area immediately after reading the message is an empty area.

  Next, in a modification, a procedure for writing messages transmitted from the control ECU 3a on the transmission side in the message box 4 in a predetermined order will be described with reference to the flowchart of FIG. FIG. 7 is a flowchart in which S100 is added after S4 in the flowchart of the embodiment of FIG. 5, S101 is added after S7, and S102 is added after S9. Therefore, the processes other than S100 to S102 (S5 is also partly changed) are the same as the processes in the flowchart in FIG.

  In S4 in FIG. 7, the updating unit 10 updates the unit information related to the storage area information from “1” to “0” in the area (N−1) of the unit area 4b. Further, in the area (N) of the unit area 4b, the unit information related to the storage area information is updated from “0” to “1”. In other words, the storage area information is updated to information indicating the termination area by writing a new message in the termination area. Then, the process proceeds to S100.

  In S100, it is determined whether or not the message reading process is finished. When the reading process is ended due to the end of the reading time zone (S100: YES), the updating unit 10 changes the unit information regarding the storage area information from “1” to “1” in the area (N) of the unit area 4b. Update to "0" to finish the control. If the reading process is not completed (S100: NO), the process proceeds to S5.

  In S5, when a new message is transmitted from the transmission-side control ECU 3a, the control ECU 2a determines whether or not the ID value of the transmitted message matches (or partially matches) the filter value 11. judge. If the filter value 11 of the message box 4 matches the ID value of the transmitted message (S5: YES), the process proceeds to S6. If the filter value 11 and the message ID value do not match (S5: NO), the process proceeds to S100. Return to.

  In S7 in FIG. 7, the updating unit 10 updates the unit information related to the storage area information from “1” to “0” in the terminal area of the unit area 4b. Further, the unit information related to the storage area information is updated from “0” to “1” in the tip area of the unit area 4b. That is, since the area indicated by the storage area information is the terminal area, the storage area information is updated to information indicating the tip area. Specifically, the unit information related to the storage area information is updated from “1” to “0” in the terminal area (N = 3). In the area (N = 0) which is the tip area, the unit information regarding the storage area information is updated from “0” to “1”. Then, the process proceeds to S101.

  In S101, it is determined whether or not the message reading process is finished. If the reading process has ended due to the end of the reading time period (S101: YES), the updating unit 10 updates the unit information related to the storage area information from “1” to “0” in the leading end area. End the control. If the reading process is not completed (S101: NO), the process proceeds to S8.

  In S9 in FIG. 7, the updating unit 10 updates the unit information related to the storage area information from “1” to “0” in the area (N−1) of the unit area 4b. Further, in the area (N) of the unit area 4b, the unit information related to the storage area information is updated from “0” to “1”. That is, each time a new message is written, the storage area information is updated to information indicating an area arranged next to the area indicated by the storage area information. Then, the process proceeds to S102.

  In S102, it is determined whether or not the message reading process has been completed. If the reading process has ended due to the end of the reading time period (S102: YES), the updating means 10 changes the unit information related to the storage area information from “1” to “1” in the area (N) of the unit area 4b. Update to "0" to finish the control. If the reading process is not completed (S102: NO), the process proceeds to S10.

  As described above, when the reading process is completed, all the unit information related to the storage area information is cleared to “0” in all the unit areas 4b in the message storage area 4a. Therefore, next, when storing a message, the message is stored from the front end area of the message box 4.

  Similarly, processing procedures for reading messages from the message box 4 in a predetermined order will be described with reference to the flowchart of FIG. FIG. 8 is a flowchart in which S200 is added after S13 in the flowchart of the embodiment of FIG. 6, S201 is added after S15, and S202 is added after S17. Therefore, the processing other than S200 to S202 is the same as the processing of the flowchart in FIG.

  In S13 in FIG. 8, the updating unit 10 updates the unit information related to the output area information from “1” to “0” in the area (M−1) of the unit area 4b. Further, in the area (M) of the unit area 4b, the unit information regarding the output area information is updated from “0” to “1”. That is, when a new message is read from the termination area, the output area information is updated to information indicating the termination area. Then, the process proceeds to S200.

  In S200, it is determined whether or not the tip area is an empty area. When the leading end area is an empty area (S200: YES), the updating unit 10 updates the unit information related to the output area information from “1” to “0” in the end area, and ends the reading time zone. End control. If the tip area is not an empty area (S200: NO), the process proceeds to S14.

  In S15 in FIG. 8, the updating unit 10 updates the unit information related to the output area information from “1” to “0” in the terminal area of the unit area 4b. Further, the unit information related to the output area information is updated from “0” to “1” in the tip area of the unit area 4b. That is, since the area indicated by the output area information is the terminal area, the output area information is updated to information indicating the tip area. Then, the process proceeds to S201.

  In S201, it is determined whether or not the area (1), which is the area immediately after the tip area, is an empty area. When the area (1) is an empty area (S201: YES), the updating unit 10 updates the unit information related to the output area information from “1” to “0” in the leading end area, and ends the reading time zone. To finish the control. If the area (1) is not an empty area (S201: NO), the process proceeds to S16.

  In S17 in FIG. 8, the updating unit 10 updates the unit information related to the output area information from “1” to “0” in the area (M−1) of the unit area 4b. Further, in the area (M) of the unit area 4b, the unit information regarding the output area information is updated from “0” to “1”. That is, each time a new message is read, the output area information is updated to information indicating an area arranged next to the area indicated by the output area information. Then, the process proceeds to S202.

  In S202, it is determined whether or not the area (M + 1) is a free area. When the area (M + 1) is an empty area (S202: YES), the updating unit 10 updates the unit information related to the output area information from “1” to “0” in the area (M) of the unit area 4b. End the reading time zone and finish the control. If the area (M + 1) is not an empty area (S202: NO), the process proceeds to S18.

  As described above, when there is no message to be read next, all the unit information related to the output area information is cleared to “0” in all the unit areas 4b in the message storage area 4a. Then, when the reading time period ends, the reading process ends. Therefore, next, when the reading time period is started and a message is output, the message is output from the tip area of the message box 4.

  Therefore, in the modified example, when the last stored message is read, the unit information of the storage area and the output area are all cleared to “0” and the initial state is set. Therefore, when the reading process is finished, writing and reading are performed again from the tip region. Therefore, when writing and reading again after reading processing, messages can be written and read without searching the writing and reading area, and the data storage and output speed can be improved. It becomes.

  The embodiments and the modifications can be combined as appropriate, and the communication device of the present invention can be used as appropriate in LIN communication and other communication devices as well as CAN communication.

1 In-vehicle communication device
2 Receiving side CAN node (receiving side control ECU 2a)
3 Transmitting side CAN node (transmitting side control ECU 3a)
4 Message box 4a Message storage area 4b Unit area 5 CPU
6 RAM 7 ROM
8 Communication bus (CAN bus) 9 Status management means 10 Update means 11 Filter value

Claims (4)

Have a message box for storing a message is received data, when reading the message from the message box to search the message to the end region from the tip region of the message storage area of the message box, obtained in the search In the in- vehicle communication device in which a plurality of nodes to be read in order from the message are connected,
The node before in texture message storage area, and the tip region information indicating the tip region, and the termination area information indicating the termination region, the storage area information indicating the storage area storing just before the message A status management means for managing output area information indicating an output area in which the message was output immediately before,
The state management means includes
When the storage area and the end area are the same as a new write area for writing the message, the front end area is specified, and when the storage area and the end area are not the same, immediately after the storage area And specify the area of
When the output area and the end area are the same as the reading area for newly reading the message, the tip area is specified, and when the output area and the end area are not the same, immediately after the output area specify the area,
The state management means instructs the reading of the message stored in the message storage area by determining a reading time zone;
An in-vehicle communication device that performs a writing process to a new message box while an interruption process occurs during reading of the message in the reading time period and the reading process is delayed . When the message is newly written to or read from the designated write area or read area, the state management means stores the storage area information or the output area information as the write area or read area. vehicle communication device according to 請 Motomeko 1 that have a updating means for updating the. The message storage area is composed of a plurality of continuous unit areas, and in the unit area, the front end area information, the end area information, the storage area information, and the output area information are present as unit information. vehicle communication device according to 請 Motomeko 1 or 2 that is housed together with the message. The state management means divides and instructs to write the long message, and the divided message is written and read in the correct order by the storage area information and the output area information. vehicle communication device according to any one of that請 Motomeko 1-3.

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