JP6692400B2 - Electronic control unit for automobile - Google Patents

Description

  The present invention relates to a vehicle electronic control device.

  An electronic control unit for an automobile such as an ECU (Electronic Control Unit) for an automobile is equipped with a nonvolatile memory (for example, a flash ROM (Read-Only Memory)) capable of electrically erasing and writing data. The electronic control device controls an in-vehicle device (for example, a fuel injection device) by a control program or the like stored in a non-volatile memory.

  When writing data such as a control program to the non-volatile memory, as described in Japanese Patent Application Laid-Open No. 2008-146521 (Patent Document 1), a writing tool for transferring write data to an electronic control device is electronically controlled. Connect to equipment. Then, the electronic control device writes the write data in the nonvolatile memory while transferring the write data from the writing tool to the electronic control device.

JP, 2008-146521, A

By the way, the electronic control unit for a vehicle performs communication by using a different communication buffer for each device as a communication partner. Therefore, when receiving the write data transferred from the writing tool, the vehicle electronic control unit can use only the communication buffer allocated for the communication with the writing tool, and therefore the size of the data that can be received in one communication. Was limited.
Therefore, for example, in the case of communication in which the response is transmitted to the writing tool every time data is received from the writing tool, the electronic control unit for the vehicle must perform the same number of transmissions as the number of receptions. become. Therefore, the number of times of communication between the vehicle electronic control unit and the writing tool increases, which is one of the causes for extending the time for transferring the writing data.

  In view of these problems, the present technology aims to provide a technology for reducing the time required to transfer write data in an electronic control device for an automobile.

An electronic control device for a vehicle for solving the above-mentioned problem is an electronic control device for a vehicle, which is connected to at least an external writing device for writing a control program for controlling a vehicle and a setting program for a communication buffer. The electronic control device includes a volatile memory that temporarily holds a control program and data, a non-volatile memory that can electrically erase and write data, and a first mail used for CAN communication with the external writing device. A communication circuit unit having a second mailbox used for CAN communication between the box and an external device for controlling the vehicle, and the communication buffer setting program received from the external writing device causes the second a mailbox as said first mailbox allocation, the first mailbox and the first of And wherein the receiving control programs and data using the second mailbox assigned as chromatography mailbox.

  According to the present technology, it is possible to reduce the number of times of communication between the vehicle electronic control device and the external writing device in the vehicle electronic control device, and it is possible to shorten the time required to transfer the write data.

It is explanatory drawing of an ECU manufacturing process and an application program writing process. It is a block diagram of ECU and a writing tool. It is a figure which shows the detail of a communication buffer area. It is the figure which showed the procedure of the application program writing process with the flowchart. It is a figure which shows the outline of a program writing whole process. It is a figure which shows the detail of a communication buffer area after a communication environment is changed. It is a flowchart of the process which the data transfer program of a writing tool performs. It is a flowchart of the process which the data transfer program of a writing tool performs. It is a flowchart of the process which the data transfer program of a writing tool performs. It is a flowchart of the process which the data transfer program of a writing tool performs. 6 is a flowchart of a process executed by a RAM expansion program of the ECU. It is a flow chart of processing which a writing main program of ECU performs. It is a flow chart of processing which a writing main program of ECU performs. It is a flow chart of processing which a writing main program of ECU performs. It is a flow chart of processing which a writing main program of ECU performs. 7 is a flowchart of a process executed by a writing subprogram of the ECU. It is a figure which shows the sequence of the Example of the transfer and writing process of an application program.

Hereinafter, a technique of an embodiment for carrying out the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows an ECU manufacturing process 10 and an application program writing process 20 for writing an application program (for example, an engine control program) into a ROM (for example, a flash ROM) mounted on the ECU 100.

In the ECU manufacturing process 10, a minimum necessary program (hereinafter, abbreviated as a minimum program) that allows a hardware inspection program to be executed in a ROM mounted on the ECU 100 and an application program to be written in a later process. Write) and inspect.
The ECU manufacturing process 10 is, for example, part of the work performed by an ECU supplier or the like.

In the application program writing step 20, the writing tool 200 (external writing device) is used to write the application program corresponding to the vehicle type into the ROM on the ECU 100. As a result, the ECU 100 supplied from the ECU manufacturing process 10 becomes the ECU 100 for each vehicle type.
In the subsequent inspection process, it is inspected whether or not the application program corresponding to the automobile is written in the ROM of the ECU 100 mounted on the automobile. Further, the application program writing process 20 is a work performed in relation to the ECU assembling process in, for example, an automobile factory.

As described above, the ECU 100 is common to all vehicle types before the ROM writing in the application program writing step 20, and therefore, for example, an ECU supplier or the like manufactures an ECU common to each vehicle type and delivers it to an automobile factory or the like. Good. Therefore, the ECU supplier and the like do not need to perform programming, manufacturing, delivery management, etc. of the ECU 100 for each vehicle type.
Further, in an automobile factory or the like, it becomes unnecessary to hold and manage the ECU 100 for each vehicle type (stock status, etc.) before writing the ROM in the application program writing step 20. Therefore, by these steps, there is a merit that manufacturing and management can be significantly reduced in the ECU supplier and the automobile factory.

However, in an automobile factory or the like, an application program writing step 20 that does not exist in the past is newly added. In the application program writing step 20, it is required to quickly write the application program corresponding to the vehicle type in the ROM.
The configurations of the ECU 100 and the writing tool 200 that meet this request are shown in FIG.

The ECU 100 is for controlling fuel injection, ignition, and the like in a vehicle engine, and includes a ROM 110, a microcomputer 120, a RAM (Random Access Memory) 130 that is a volatile memory, and a communication circuit 140. It
The ECU 100 is detachably connected to the writing tool 200 by a communication line 300 such as a CAN (Controller Area Network).

The microcomputer 120 includes a CPU, a cache memory, etc., and executes various programs stored in the ROM 110 and the RAM 130.
The RAM 130 has a first buffer area 133 and a second buffer area 134. The first buffer area 133 and the second buffer area 134 are used when writing data to the ROM 110.

The communication circuit 140 has a communication buffer area 141. The communication buffer area 141 is used when the ECU 100 communicates with another device by the communication circuit 140.
The writing tool 200 includes a storage 210 (for example, a hard disk) and a communication circuit 240.
The writing tool 200 includes a terminal (for example, a personal computer) and a device connected to the ECU 100, and an operator who operates the writing tool 200 can interactively give instructions to the writing tool 200. The writing tool 200 transfers the writing data stored in the storage 210 to the ECU 100.

The storage 210 stores application programs transferred to the ECU 100.
The communication circuit 240 has a communication buffer area 241. The communication buffer area 241 is used when the writing tool 200 communicates with the ECU 100 by the communication circuit 240.

Here, FIG. 3 shows the details of the communication buffer area 141 used when the ECU 100 communicates with the writing tool 200.
In the communication buffer area 141 of the ECU 100, there are a plurality of communication buffers of a fixed size (for example, mailboxes in CAN). When communicating with each device, ECU 100 uses a communication buffer, which is pre-allocated for communication with a device as a communication partner, among the communication buffers in communication buffer area 141.
Each communication buffer is divided into a transmission buffer (TX) used for transmitting data and a reception buffer (RX) used for receiving data. In addition, the number of communication buffers that are pre-allocated for communication with a device that is a communication partner is the number that is used in the communication environment in the vehicle.

On the other hand, the communication buffer area 241 of the writing tool 200 has a plurality of communication buffers of a certain size.
The size of the communication buffer in the communication buffer area 241 is the same as the size of the communication buffer in the communication buffer area 141 of the ECU 100.

  In FIG. 3, in the communication buffer area 141 of the ECU 100, two communication buffers (one TX, one abbreviated as a communication buffer for a writing tool) used by the ECU 100 to communicate with the writing tool 200 (hereinafter referred to as a communication buffer for a writing tool) are used. RX1) is assigned. The other communication buffers in the communication buffer area 141 are allocated for communication with devices other than the writing tool 200.

Therefore, the size of the communication buffer is 8 bytes, and the ECU 100 and the writing tool 200 communicate with each other in synchronization so that the ECU 100 returns a response to the writing tool 200 each time one piece of data is received. If this is done, one RX is used to receive one data, so 16 times of communication are required before the ECU 100 acquires 64 bytes of data.
That is, the writing tool 200 transfers 64 bytes of data in 8 bytes, and the ECU 100 returns a response to the writing tool 200 each time 8 bytes are received, so the number of times of communication becomes 16 times.

The procedure in the application program writing step 20 is shown in FIG.
In step 1 (abbreviated as “S1” in the figure. The same applies hereinafter), the worker connects the ECU 100 to the writing tool 200. When the ECU 100 is connected to the writing tool 200, the power is turned on, and the microcomputer 120 executes a minimum program to enable communication with the writing tool 200 and wait for reception of data transferred from the writing tool 200. Becomes

In step 2, the operator specifies an application program (for example, an engine control program for vehicle type A) to be written in the ROM 110. When the application program is designated, the writing tool 200 transfers the designated application program to the ECU 100.
The ECU 100 writes the application program in the ROM 110 while receiving the transferred application program and the like. Hereinafter, the process of step 2 will be referred to as the entire program writing process.

In step 3, the worker removes the ECU 100 from the writing tool 200.
After this, the ECU 100 is assembled in each vehicle. Further, in the inspection process, it is checked whether or not the correct application program is written in the ROM 110 of the ECU 100 (for example, whether or not the application program corresponds to the assembled vehicle). If the correct application program has not been written, the writing tool 200 is connected to the ECU 100 installed in the automobile to write the correct application program.

FIG. 5 shows an outline of the entire program writing process.
In step 11, the writing tool 200 activates the data transfer program for transferring the writing program and the application program when the operator specifies the writing program and the application program for writing in the ROM 110. Then, the writing tool 200 transmits a message for starting the transfer of the writing program (for example, the writing program 2) to the ECU 100 by the data transfer program and also transfers the designated writing program.

Here, the writing program designated by the operator is stored in the writing program database 211 existing in the storage 210.
The writing program is transferred to the ECU 100, and the ECU 100 executes initialization processing such as change of communication environment, reception processing of write data, and processing of writing write data in the ROM 110.
The write program is composed of a write main program and a write sub program.

The write main program operates on the ECU 100 after being transferred to the ECU 100, and establishes a communication environment (communication buffer usage method, communication speed, encryption method, etc.) according to the write program between the writing tool 200 and the ECU 100. Establish.
Further, the write main program writes the application program transferred from the writing tool 200 in the ROM 110 under the write condition (address of the area of the ROM to be written, etc.) according to the write program.
The write subprogram is activated from the write main program and copies the received data in the communication buffer area 141 to the first buffer area and the second buffer area.

Further, the application program designated by the worker is stored in the application program database 212 existing in the storage 210.
Each application program is an engine control program or the like according to each vehicle type.

In step 12, when the ECU 100 receives a message for starting the transfer of the writing program from the writing tool 200 which is the transfer source of the writing program, the ECU 100 activates the RAM expansion program stored in the ROM 110.
Here, the RAM expansion program performs a process of expanding the writing program received by the ECU 100 on the RAM 130. Therefore, the ECU 100 expands the received write program in the RAM 130 by the RAM expansion program while receiving the write program.

In step 13, when the expansion of the writing program is completed, the ECU 100 starts the writing program expanded in the RAM 130 by the RAM expanding program.
In step 14, the ECU 100 changes the communication environment between the ECU 100 and the writing tool 200 to a communication environment according to the writing program by the writing program, and requests the writing tool 200 to transmit the application program. To send.

  In step 15, when the writing tool 200 receives the message requesting the transmission of the application program, the data transfer program starts the transfer of the application program (for example, the application program 1) designated by the operator to the ECU 100. ..

  In step 16, while receiving the application program from the writing tool 200, the ECU 100 writes the received application program in the ROM 110 based on the writing condition by the writing main program and the writing subprogram.

After the writing is finished, the ECU 100 is removed from the writing tool 200 and the power is turned off. Next, when the power of the ECU 100 is turned on, the communication environment of the ECU 100 returns to the initial state (the communication environment similar to that in step 1).
Further, if an abnormality (for example, communication with the writing tool 200 is interrupted during writing program operation) occurs during the entire program writing process, the ECU 100 resets itself. Then, the communication environment of the ECU 100 returns to the initial state.

Therefore, by selecting the write program, a more suitable write program can be operated in the entire program write process according to the communication environment to be used, the write condition of the application program, and the like.
Therefore, for example, by operating a writing program having a higher communication speed, high-speed communication can be performed, and the entire program writing process can be speeded up.

  Further, since the writing program is transferred to the ECU 100 during the entire program writing process, it is not necessary to store the writing program in the ROM 110, and the usage amount of the ROM 110 can be reduced.

Furthermore, by changing the writing program, new functions can be added to the entire program writing process.
Even in a situation where the ECU 100 is connected to another device in addition to the writing tool 200, the ECU 100 may block communication with other devices during the entire program writing process and communicate with only the writing tool 200. Thus, the entire program writing process can be executed.

  As an example of performing the entire program writing process in a situation where another device is connected to the ECU 100 in addition to the writing tool 200, there is a writing of an application program in a state where the ECU 100 is installed in an automobile.

In this case, in order to prevent the competition of the communication paths, the communication environment used by the ECU 100 when communicating with the writing tool 200 needs to be a communication environment common to other devices (for example, the communication speed is common).
Therefore, the operator designates a writing program that establishes a common communication environment with other devices, and executes the entire program writing process. At this time, the ECU 100 communicates only with the writing tool 200 and cuts off communication with other devices.

Next, a method of using the communication buffer area 141 used when the ECU 100 receives the application program transferred from the writing tool 200 will be described.
In a situation such as the application program writing step 20, since the ECU 100 does not communicate with a device other than the writing tool 200, a communication buffer (hereinafter referred to as communication for other devices) pre-allocated for communicating with a device other than the writing tool 200. (Abbreviated as buffer) is not used.

  Therefore, the writing program can be modified to use the communication buffer for another device in addition to the communication buffer for the writing tool so as to be used for communication between the ECU 100 and the writing tool 200.

FIG. 6 shows details of the changed communication buffer area 141.
In the example of FIG. 6, when communicating with the writing tool 200, the ECU 100 uses two communication buffers as writing tool communication buffers and seven communication buffers of other device communication buffers.
At this time, the 9 communication buffers used by the ECU 100 are set to 1 for TX and 8 for RX. At this time, the communication buffer in the communication buffer area 241 of the writing tool 200 has eight TXs and one RX.

For example, while the size of one communication buffer is 8 bytes, and the ECU 100 returns a response to the writing tool 200 each time one data is received, the ECU 100 and the writing tool 200 are synchronized with each other. When performing communication, since eight RX can be used to receive one data, it will be nine times of communication as compared with the conventional method until the ECU 100 acquires 64 bytes of data from the writing tool 200. ..
That is, the writing tool 200 transfers 64 bytes of data as one piece of data in units of 8 bytes, and the ECU 100 returns a response to the writing tool 200 every time eight pieces of 8 bytes of data are received. Therefore, the number of communication times is 9.

  The writing program uses the number of communication buffers used by the ECU 100 to communicate with the writing tool 200, the size of data transmission / reception, an integral multiple of the size of data transmission / reception, the size of one-time writing to the ROM 110, or the ROM 110. Alternatively, the number may be an integer multiple of the size of one writing.

As described above, since communication can be performed using the communication buffer for other devices in addition to the communication buffer for the writing tool, the number of times of communication is reduced and the time required for data transfer is reduced in the communication for synchronization. It is possible to reduce the data transfer speed.
In addition, since the communication buffer for another device is used, the writing tool 200 can continuously transfer data without worrying about overwriting the communication buffer.

  If there is an unused communication buffer that is not allocated to any device in the communication buffer area 141, the writing program uses the unused communication buffer for communication between the ECU 100 and the writing tool 200. Can also be changed.

Next, each program that operates in the entire program writing process will be described.
7 and 8 are flowcharts of the processing executed by the writing tool 200 by the data transfer program triggered by the operator designating the writing program and the application program in the writing tool 200.

  In step 31, the data transfer program sends to ECU 100 a message indicating that the transfer of the writing program has started (a transfer start message of the writing program).

In step 32, the data transfer program sequentially transfers the data of the designated writing program by a size that the ECU 100 can receive in one communication.
In step 33, the data transfer program determines whether or not a request message for the next data is received from the ECU 100. If the data transfer program has received the next data request message from the ECU 100, the process proceeds to step 34 (Yes), while if the next data request message has not been received from the ECU 100, the process proceeds to step 33. Return to (No).

  In step 34, the data transfer program determines whether or not the transfer of the designated write program has been completed. If the transfer of the designated write program has been completed, the data transfer program advances the processing to step 35 (Yes), while if the transfer of the designated write program has not been completed, the processing returns to step 32. (No).

  In step 35, the data transfer program transmits to the ECU 100 a message indicating that the transfer of the writing program has been completed (writing program transfer completion message).

In step 36, the data transfer program determines whether or not a message has been received from the ECU 100.
If the data transfer program has received the message from the ECU 100, the process proceeds to step 37 (Yes), while if the message has not been received from the ECU 100, the process returns to step 36 (No).

In step 37, the data transfer program determines whether the message received from the ECU 100 is a message to the effect that the writing program has been properly transferred.
If the received message is a message indicating that the writing program has been legally transferred, the data transfer program advances the process to step 38 (Yes), while the received message indicates that the writing program has been legally transferred. If not, the process proceeds to step 39 (No).

In step 38, the data transfer program executes the application transfer processing subroutine.
The application transfer processing sub-routine performs processing of dividing the data of the specified application program into a plurality of pieces and transferring them. Hereinafter, the data to be divided and transferred will be referred to as divided data.

  In step 39, the data transfer program makes settings such that the write program is transferred from the beginning again (for example, the index of the write program is returned to the beginning).

9 to 10 show flowcharts of the processing of the application transfer processing subroutine.
In step 41, the data transfer program determines whether the writing tool 200 has received a message from the ECU 100. If the data transfer program has received the message from the ECU 100, the process proceeds to step 42 (Yes), while if the message has not been received from the ECU 100, the process returns to step 41 (No).

  In step 42, the data transfer program determines whether or not the received message is a message indicating a divided data transmission request (divided data transmission request message). If the received message is not the divided data transmission request message, the process proceeds to step 43 (Yes), while if the received message is the divided data transmission request message, the process proceeds to step 44 ( No).

  In step 43, the data transfer program determines whether or not the received message is a message indicating a resend request for divided data (a resend request message for divided data). If the received message is not the fragment data resend request message, the process proceeds to step 47 (Yes), while if the received message is the fragment data resend request message, the process proceeds to step 46. (No).

In step 44, the data transfer program reads the data from the position indicated by the read pointer representing the index of the designated application program, and adds a checksum to the read data to create divided data.
Here, the data read size is a value obtained by subtracting the size of the checksum from the total size of each RX used in the communication environment established in the ECU 100 by the transferred write program.

  The initial value of the read pointer is the start address of the application program. The read pointer is incremented by the data read size each time step 44 is executed.

  For example, when the total size of each RX used in the communication environment established by the transferred write program is 64 bytes and the checksum size is 2 bytes, the data read size is 62 bytes and the divided data size is It will be 64 bytes.

For data verification, there is a CRC (Cyclic Redundancy Check) in addition to the checksum.
In addition, for the divided data, the writing tool 200 side includes a sequence number indicating which transferred divided data is included in the divided data, and the ECU 100 side checks the sequence number of the received divided data. It may be possible to check whether the divided data has been received in the correct order.

In step 45, the data transfer program transfers the created divided data to the ECU 100. At this time, since the data transfer program transfers the divided data, it divides the divided data according to the TX size of the communication buffer area 241 and stores the divided data in each TX of the communication buffer area 241.
For example, when there are 8 divided bytes of 8 bytes in the communication buffer area 241, and the divided data is 8 bytes, the data transfer program divides the divided data into 8 pieces of 8 bytes and each TX is divided into 8 pieces of data. To store.
The data stored in TX is transferred to ECU 100 by communication circuit 240.

  In step 46, the data transfer program transfers the created divided data to the ECU 100 again.

In step 47, the data transfer program determines whether the received message is a message indicating that the divided data was not normally written in the ROM 110 of the ECU 100 (divided data write NG message).
If the received message is not the divided data write NG message, the process proceeds to step 48 (Yes), while if the received message is the divided data write NG message, the process proceeds to step 50 (step 50). No).

In step 48, the data transfer program determines whether the transfer of the application program has been completed to the end by determining whether the read pointer has reached the end of the application program.
If the transfer of the application program has been completed to the end, the data transfer program advances the processing to step 49 (Yes), while if the transfer of the application program has not been completed to the end, the processing advances to step 41 (No). ).

  In step 49, the data transfer program transmits a message indicating that the transfer of the application program is completed (application transfer completion message) to ECU 100.

  In step 50, the data transfer program sets the value of the read pointer to the start address of the application program in order to transfer the application program from the beginning again.

  FIG. 11 shows a flowchart of the processing executed by the ECU 100 by the RAM expansion program triggered by the ECU 100 receiving the transfer start message of the writing program.

In step 51, the RAM expansion program determines whether the ECU 100 has received data from the writing tool 200.
If the RAM expansion program has received the data from the writing tool 200, the process proceeds to step 52 (Yes), while if the data has not been received from the writing tool 200, the process returns to step 51 (No).

In step 52, the RAM expansion program determines whether the received data is a transfer completion message of the writing program.
If the received data is the write program transfer completion message, the process proceeds to step 53 (Yes). If the received data is not the write program transfer completion message, the RAM expansion program advances the process to step 56. (No).

In step 53, the RAM expansion program determines by checksum or the like whether the transferred write program is valid.
If the transferred write program is valid, the RAM expansion program advances the process to step 54 (Yes), while if the transferred write program is not correct, the process advances to step 58 (No).

In step 54, the RAM expansion program sends a message to the writing tool 200 to the effect that the writing program has been properly transferred.
In step 55, the RAM expansion program activates the write main program in the write programs expanded in the RAM 130.

In step 56, the RAM expansion program expands the received write program data from the RX of the communication buffer area 141 to the RAM 130.
In step 57, the RAM expansion program sends a request message for the next data to the writing tool 200.

  In step 58, the RAM expansion program sends a message to the writing tool 200 to the effect that the writing program has not been properly transferred.

  FIG. 12 shows a flowchart of processing executed by the ECU 100 by the write main program triggered by activation of the write main program.

  In step 61, the writing main program changes the communication environment for the ECU 100 to communicate with the writing tool 200 according to the transferred writing program. When the ECU 100 can communicate with other devices other than the writing tool 200, the communication environment may not be changed.

In step 62, the write main program executes the ROM write processing subroutine.
The ROM writing processing subroutine receives the divided data from the writing tool 200, which is the transfer source of the divided data, and writes the application program data in the ROM 110 based on the divided data.

13 to 15 show a ROM writing processing subroutine.
In step 71, the write main program sets the first buffer area 133 to a copy area for copying the divided data received from the writing tool 200.

In step 72, the write main program activates the write subprogram.
In step 73, the write main program substitutes 1 into a variable n, which is a counter indicating which number of data (data of the application program) to be written in the ROM 110 is being processed.

In step 74, the writing main program transmits a divided data transmission request message to the writing tool 200 in order to obtain the first divided data.
In step 75, the write main program determines whether or not a message (divided data copy completion message) indicating that the divided data received from the writing tool 200 has been copied to the copy area has been notified from the writing subprogram. .. The write main program advances the process to step 76 if the divided data copy completion message is notified (Yes), while returning the process to step 75 if the divided data copy completion message is not notified (No). ).

In step 76, the write main program refers to the first divided data stored in the copy area and uses the checksum included in the divided data to determine whether the first divided data has been successfully received. To determine.
The write main program advances the process to step 77 if the first divided data is normally received (Yes), while proceeding to step 78 if the first divided data is not normally received (No). ).

  In step 77, the write main program sets the first buffer area 133 to the write area used when writing the divided data to the ROM 110, and sets the second buffer area 134 to the copy area. To do.

In step 78, the write main program sends a divided data resend request message to the writing tool 200 in order to obtain the first divided data again.
A message indicating that the divided data could not be properly received (divided data reception NG message) may be transmitted to the writing tool 200 together with the divided data resend request message.

In step 79, the write main program sends a divided data transmission request message to the writing tool 200 to obtain the second divided data.
A message indicating that the previous divided data was successfully received (divided data received OK message) may be transmitted to the writing tool 200 together with the divided data transmission request message.

  In step 80, the write main program removes the checksum from the n-th divided data stored in the write area, and writes the data stored in the write area to the ROM 110 according to the write condition.

In step 81, the write main program determines whether or not the nth data has been normally written in the ROM 110 by executing the verification of the write data.
The write main program advances the processing to step 82 if the n-th data is normally written in the ROM 110 (Yes), while performing the processing if the n-th data is not normally written in the ROM 110. Proceed to step 84 (No).

  The verification of the write data is performed, for example, by comparing the content of the area for writing with the content of the area of the written ROM 110.

  In step 82, the write main program determines whether or not a split data copy completion message is notified from the write subprogram. The write main program advances the process to step 83 if the divided data copy completion message is notified (Yes), while returning the process to step 82 if the divided data copy completion message is not notified (No). ).

In step 83, the write main program determines whether the data stored in the copy area is an application transfer completion message.
The write main program ends the process if the data stored in the copy area is the application transfer completion message (Yes), while the data stored in the copy area must be the application transfer completion message. If so, the process proceeds to step 87 (No).

In step 84, the write main program sends a write data write NG message to the write tool 200.
In step 85, the write main program erases the data in the written area of the ROM 110.

In step 86, the write main program sets the first buffer area 133 as a copy area.
In step 87, the write main program determines whether or not the (n + 1) th divided data has been successfully received by verifying the (n + 1) th divided data copied to the copy area with a checksum. The write main program advances the processing to step 88 if the n + 1-th divided data has been normally received (Yes), while advancing the processing to step 91 if the n + 1-th divided data has not been normally received. (No).
The verification of the (n + 1) th divided data may be performed by the writing subprogram immediately after receiving the (n + 1) th divided data.

  In step 88, the write main program sets the buffer area set for copying as a write area and the buffer area set for writing as a copy area.

In step 89, the writing main program transmits a division data transmission request message to the writing tool 200 in order to acquire the (n + 2) th division data.
A message indicating that the nth divided data has been written in the ROM 110 (divided data write OK message) and a message indicating that the (n + 1) th divided data has been received (divided data reception OK) together with the divided data transmission request message. The message) may be transmitted to the writing tool 200.

In step 90, the write main program adds 1 to n.
In step 91, the write main program sends a re-transmission request message for the divided data to the writing tool 200 in order to obtain the (n + 1) th divided data again. A message indicating that the (n + 1) th divided data could not be received normally (divided data reception NG message) may be transmitted to the writing tool 200 together with the divided data retransmission request message.

FIG. 16 shows a flowchart of processing executed by the writing subprogram by the ECU 100 when the ECU 100 receives data from the writing tool 200.
In step 101, the write subprogram copies the received divided data from the RX of the communication buffer area 141 to the copy area.

In step 102, the write subprogram notifies the write main program of a copy completion message of the divided data.
The copy area may be set to an area corresponding to RX of the communication buffer area 141, and the ECU 100 may use the copy area to receive data. In this case, the process of copying the divided data from the RX of the communication buffer area 141 to the copy area is unnecessary.

  Further, when there is a difference between the processing time from the transmission request of the divided data to the completion of copying and the time required for writing the data to the ROM 110 and the verification processing, when one of the longer ones is completed, The process of receiving the divided data and the process of writing the data in the ROM 110 may be started.

In this way, the received divided data is copied to the RX of the ECU 100, and two buffer areas for writing in the ROM 110 are prepared. Then, of the two buffer areas, one buffer area is used for the writing processing to the ROM 110, while the other buffer area is used for the processing of copying the divided data received by the ECU 100.
As a result, in the ECU 100, the process of writing data in the ROM 110 using one buffer area, the reception of the divided data, and the processing of copying the received divided data to the other buffer area can be performed in parallel. .. Therefore, the time required for the entire program writing process can be reduced.

  Further, in order to realize these processes, the process on the ECU 100 side may be changed, so that the time required for the entire program writing process can be reduced without significantly changing the writing tool 200.

The sequence of the embodiment of the transfer and write processing of the application program is as shown in FIG.
Here, the size of the program transferred by the writing tool 200 is 180 bytes. The total size of each RX of the ECU 100 is 64 bytes.

The ECU 100 transmits a first divided data transmission request message to the writing tool 200.
The writing tool 200 reads the first 62 bytes of data of the application program, adds a 2-byte checksum, creates the first divided data, and transfers the divided data to the ECU 100.

After receiving the first divided data, the ECU 100 copies the first divided data from the RX of the communication buffer area 141 to the first buffer area 133.
Next, the ECU 100 verifies the divided data for the first time and transmits a transmission request message for the second divided data to the writing tool 200. Further, the ECU 100 uses the first buffer area 133 to perform processing of writing data in the ROM 110 and verification of write data.

  When receiving the transmission request message for the second divided data, the writing tool 200 reads the 62-byte data to be transferred next, adds a checksum to create the second divided data, and transfers the second divided data to the ECU 100.

After receiving the second divided data, the ECU 100 copies the second divided data from the RX of the communication buffer area 141 to the second buffer area 134. Next, the ECU 100 verifies the second divided data.
Further, when the verification of the second divided data and the verification of the first write data are completed, the ECU 100 transmits a transmission request message for the third divided data to the writing tool 200. Further, the ECU 100 uses the second buffer area 134 to perform a process of writing data in the ROM 110 and a writing verification.

  After receiving the transmission request message for the third divided data, the writing tool 200 reads the remaining 56-byte data, adds a checksum to create the third divided data, and transfers the third divided data to the ECU 100.

The process after the ECU 100 receives the third divided data is the same as the process after the second data is received.
When the writing tool 200 receives the transmission request message for the fourth divided data, the writing tool 200 transmits an application transfer completion message to the ECU 100.

It should be noted that although the present embodiment takes the ECU 100 as an example, it can be applied to another electronic control device equipped with a nonvolatile memory instead of the ECU 100.
Further, a plurality of ECUs 100 may be connected to one writing tool 200, and one writing tool 200 may transfer the data to be written in the ROM 110 to each ECU 100 in a time division manner.

Here, technical ideas other than the claims that can be understood from the embodiment will be described below together with the effects.
(A) The electronic control device for an automobile according to claim 1, wherein the communication buffer used for receiving the control program and the data includes a communication buffer which is not used in a communication environment in a vehicle.

  When there is an unused communication buffer that is not used by any device that is a communication partner in the in-vehicle state, one data is received by using the unused communication buffer when acquiring the control program and data. Since the size of the communication buffer that can be used for is increased, the number of times of communication can be reduced.

(B) Electronic control for automobiles, which is provided with a non-volatile memory capable of electrically erasing and writing data, and which can obtain a program for writing in the non-volatile memory for each predetermined size by communication using a communication buffer A device,
An electronic control unit for a vehicle, wherein the reception of the program is performed by using a number of communication buffers exceeding the number used in a vehicle-mounted communication environment.

(C) The electronic control for an automobile according to (B), wherein the communication buffer used for receiving the program is used by a plurality of devices as communication partners in the communication environment in the vehicle-mounted state. apparatus.

(D) The size of the communication buffer used in the reception of the program is set based on the predetermined size or the writing size to the memory, (b) or (c) Control device.

  According to these electronic control devices for automobiles, the number of times of communication is reduced in the communication for synchronization, the time required for data transfer is reduced, and the speed of data transfer can be increased.

(E) An electronic control for automobiles, which is provided with a nonvolatile memory capable of electrically erasing and writing data, and which can obtain a program for writing in the nonvolatile memory for each predetermined size by communication using a communication buffer The device
A data communication method, wherein the reception of the program is performed by a number of communication buffers that exceeds the number used in a vehicle-mounted communication environment.

  According to this data communication method, the number of times of communication is reduced in communication for synchronization, the time required for data transfer is reduced, and the speed of data transfer can be increased.

  100 ... ECU, 110 ... ROM, 141 ... Communication buffer area

Claims (1)

At least an automobile electronic control device connected to an external writing device for writing a vehicle control control program and a communication buffer setting program,
The electronic control unit for an automobile is
A volatile memory that temporarily holds the control program and data,
A non-volatile memory capable of electrically erasing and writing data,
A communication circuit unit having a first mailbox used for CAN communication with the external writing device and a second mailbox used for CAN communication with an external device for vehicle control;
Is composed of
By the external writing device the communication buffer setting program received from, the assigned second mailbox as said first mailbox, the allocated as the first mailbox and the first mailbox first An electronic control unit for a vehicle, which receives a control program and data using the mailbox of No. 2.