JP2022170949A - Control device and data rewriting method - Google Patents

Abstract

To provide a technique capable of properly performing difference reprogramming for each controller while suppressing an RAM capacity of at least one controller to be small in a control device with multiple controllers.SOLUTION: A control device comprises a first controller with a first RAM and a second controller provided for being communicable with the first controller. The second controller has a second RAM with smaller capacity than the first RAM and a nonvolatile memory capable of electrically rewriting data. The first RAM is used in a generation area of new data generated using existing data and difference data when the difference data required to rewrite the existing data stored in the nonvolatile memory from outside the control device are transmitted to the first controller.SELECTED DRAWING: Figure 1

Description

The present invention relates to a control device and a data rewriting method.

In the non-volatile memory of the microcomputer installed in the vehicle, there are product software (hereinafter referred to as product software) that enables the original functions of the microcomputer product, and reprogramming software (hereinafter referred to as reprogramming software) to rewrite the product software. described as repro software) is stored. Product software is updated (reprogrammed) by connecting a rewriting device outside the vehicle to a microcomputer and executing reprogramming software.

BACKGROUND Conventionally, an electronic control unit (ECU) including a main microcomputer and a sub-microcomputer is known. In such an electronic control device, only the main microcomputer is connected to the rewriting device, and the product software of the sub-microcomputer may be updated via the main microcomputer (see, for example, Patent Document 1).

In addition, conventionally, in order to shorten the update time of product software, the difference data between the product software already stored in the non-volatile memory (hereinafter referred to as existing software) and the product software for updating is transferred from the rewriting device to the microcomputer. Differential reprogramming (hereinafter referred to as differential reprogramming) is known for transmitting and updating product software. In differential repro, rewritten software is generated inside the microcomputer based on existing software and differential data. After erasing the existing software stored in the non-volatile memory, the generated rewriting software is written into the non-volatile memory.

JP 2016-12220 A

By the way, in differential reprocessing, it is necessary to temporarily store rewritten software generated based on existing software and differential data in a RAM (Random Access Memory) of a microcomputer. In an electronic control device having a main microcomputer and a sub-microcomputer, the specifications of the sub-microcomputer may be lower than that of the main microcomputer, and the RAM capacity of the sub-microcomputer may be small. In such a configuration, a situation may occur in which the sub-microcomputer cannot temporarily store the rewritten software in the RAM due to lack of capacity, and cannot perform differential reprocessing.

SUMMARY OF THE INVENTION In view of the above points, it is an object of the present invention to provide a technique in a control device having a plurality of controllers, capable of appropriately performing differential reprocessing in each controller while keeping the RAM capacity of at least one controller small. and

In order to achieve the above object, the control device of the present invention comprises a first controller having a first RAM, and a second controller communicable with the first controller, wherein the second controller has a second RAM whose capacity is smaller than that of the first RAM, and a non-volatile memory in which data can be electrically rewritten. When necessary difference data is transmitted to the first controller, the first RAM is used as a generation area for new data generated using the existing data and the difference data (first configuration). ing.

In the control device having the first configuration, the first controller requests the second controller to transmit the existing data when receiving the difference data from the outside, and transmits the generated new data to the second controller. 2 controller, and the second controller writes the new data into the nonvolatile memory after erasing the existing data in the nonvolatile memory (second configuration).

In the control device having the first or second configuration, the processing for generating the new data using the first RAM and the processing for erasing the existing data in the nonvolatile memory are performed in parallel (third configuration).

In the control device having any one of the first to third configurations, the communication speed between the first controller and the second controller is higher than the communication speed between the outside and the first controller. (fourth configuration).

In order to achieve the above object, a data rewriting method of the present invention provides a control device comprising a first controller having a first RAM and a second controller having a second RAM having a capacity smaller than that of the first RAM, wherein the second A method for rewriting existing data stored in a non-volatile memory of a controller, comprising the step of receiving, from the outside, differential data necessary for rewriting the existing data by the first controller; a step of transmitting the existing data; a step of generating new data based on the existing data and the difference data using the first RAM as a generation area; writing the new data into the non-volatile memory after erasing the existing data in the non-volatile memory (fifth configuration).

According to the present invention, in a control device having a plurality of controllers, it is possible to appropriately perform differential reprocessing in each controller while keeping the RAM capacity of at least one controller small.

Block diagram showing the configuration of the data rewriting system A first schematic diagram for explaining the flow of differential reprocessing executed for product software owned by the first controller. A second schematic diagram for explaining the flow of differential reprogramming executed for product software owned by the first controller. A third schematic diagram for explaining the flow of differential repro that is executed for product software owned by the first controller. Flowchart showing the flow of differential reprogramming executed for product software owned by the second controller A first schematic diagram for explaining the flow of differential reprocessing executed for product software owned by the second controller. A second schematic diagram for explaining the flow of difference repro that is executed for product software owned by the second controller. A third schematic diagram for explaining the flow of difference repro that is executed for product software owned by the second controller.

Exemplary embodiments of the invention are described in detail below with reference to the drawings. In this specification, rewriting of a program may be expressed as reprogramming. Also, reprogramming is sometimes abbreviated as repro.

<1. Data rewrite system>
FIG. 1 is a block diagram showing the configuration of a data rewriting system 100 according to an embodiment of the invention. As shown in FIG. 1 , the data rewriting system 100 includes a control device 1 and a rewriting device 2 .

In this embodiment, the control device 1 is an electronic control unit (ECU) mounted on the vehicle. However, the control device 1 may be a control device other than the electronic control device mounted on the vehicle. For example, the control device 1 may be an electronic control device mounted on a moving object other than a vehicle, such as a ship or an aircraft. The rewriting device 2 is provided outside the control device 1 . The rewriting device 2 is configured by a personal computer, for example, and has a function as a reprogramming tool that rewrites the program of the control device 1 .

The control device 1 and the rewriting device 2 are communicably connected. In this embodiment, CAN (Controller Area Network) communication is used for communication between the control device 1 and the rewriting device 2 . The rewriting device 2 is used, for example, when rewriting the program held by the control device 1 at a vehicle factory, dealer, or the like. That is, the rewriting device 2 is not always connected to the control device 1, but is connected to the control device 1 when reprogramming is required.

The program rewritten by the rewriting device 2 is, for example, a control program used by the control device 1 to execute various controls. The control program corresponds to the product software described above. Further, when updating a program (product software) using the rewriting device 2, the program is included in a type of data defined as information to be processed by a computer.

<2. Control device>
(2-1. Configuration)
As shown in FIG. 1 , the control device 1 has a first controller 11 and a second controller 12 . In this embodiment, both the first controller 11 and the second controller 12 are microcomputers (microcontrollers). Specifically, the first controller 11 is a main microcomputer, and the second controller 12 is a sub-microcomputer. The main microcomputer has higher specs than the sub microcomputer.

The first controller 11 has a first arithmetic processing unit 111 , a first RAM 112 and a first nonvolatile memory 113 . These components are appropriately connected within the first controller 11 via a bus (not shown). In this embodiment, the first arithmetic processing unit 111 is configured by a CPU (Central Processing Unit). The first RAM 112 has a capacity larger than that required to perform differential repro which will be detailed later. That is, the first controller 11 can execute differential repro.

The first nonvolatile memory 113 is an electrically rewritable memory. In this embodiment, the first non-volatile memory 113 is composed of a flash memory. Specifically, the first nonvolatile memory 113 is configured by a NAND flash memory. The first non-volatile memory 113 stores product software 113 a and repro software 113 b for the first controller 11 .

In the first controller 11, the first arithmetic processing unit 111 uses the first RAM 112 as a work area and executes arithmetic processing according to a control program (product software 113a) pre-stored in the first non-volatile memory 113. By doing so, various functions are realized. When the rewriting device 2 is connected to the control device 1, the first controller 11 can communicate with the rewriting device 2 using CAN.

The second controller 12 has a second arithmetic processing section 121 , a second RAM 122 and a second non-volatile memory 123 . These components are appropriately connected within the second controller 12 via a bus (not shown). In this embodiment, the second arithmetic processing unit 121 is configured by a CPU (Central Processing Unit). The second RAM 122 has a smaller capacity than the first RAM 112 . Specifically, the capacity of the second RAM 122 is smaller than the capacity required for the second controller 12 to independently perform differential repro. That is, the second controller 12 cannot perform differential repro on its own.

The second nonvolatile memory 123 is an electrically rewritable memory. That is, the second controller 12 has an electrically rewritable nonvolatile memory 123 . In this embodiment, the second non-volatile memory 123 is composed of a flash memory. Specifically, the second non-volatile memory 123 is composed of a NAND flash memory. The second non-volatile memory 123 stores product software 123 a and repro software 123 b for the second controller 12 .

In the second controller 12, the second arithmetic processing unit 121 uses the second RAM 122 as a work area and executes arithmetic processing according to a control program (product software 123a) pre-stored in the second non-volatile memory 123. By doing so, various functions are realized.

The second controller 12 is provided so as to communicate with the first controller 11 . Specifically, the first arithmetic processing unit 111 and the second arithmetic processing unit 121 are provided so as to be able to communicate with each other. Communication (inter-CPU communication) between the first arithmetic processing unit 111 and the second arithmetic processing unit 121 is, for example, serial communication. Serial communication may be, for example, SPI (Serial Peripheral Interface) communication.

In this embodiment, the communication speed between the first controller 11 and the second controller 12 is faster than the communication speed between the rewriting device 2 (external) and the first controller 11 . The communication speed between the first controller 11 and the second controller 12 is preferably twice or more the communication speed between the rewriting device 2 (external) and the first controller 11 . The speed of communication (SPI communication) between the first controller 11 and the second controller 12 is, for example, 2 Mbps. The speed of communication (CAN communication) between the rewriting device 2 and the first controller 11 is, for example, 500 kbps.

In this embodiment, when the rewriting device 2 is connected to the control device 1, the second controller 12 communicates with the rewriting device 2 via the first controller 11 capable of performing CAN communication with the rewriting device 2. I do. In other words, the rewriting device 2 performs CAN communication only with the first controller 11 and does not perform CAN communication with the second controller 12 .

(2-2. Difference Repro of Product Software Owned by First Controller)
Next, reprogramming of the product software 113a of the first controller 11 will be described. Differential reprogramming is used for the reprogramming. The differential reprocessing is performed by connecting the control device 1 and the rewriting device 2 and using the reprocessing software 113b stored in the first non-volatile memory 113. FIG.

In addition, in this embodiment, the control device 1 includes a first controller 11 and a second controller 12 . For this reason, the rewriting device 2 sends a signal to the control device 1 in advance as to which of the controllers 11 and 12 is targeted for the reprogramming process. In other words, the control device 1 can recognize which of the controllers 11 and 12 is targeted for the reprogramming process. Hereinafter, the difference reprocessing of the product software 113a of the first controller 11 will be described on the assumption that the control device 1 recognizes that the reprocessing is for the product software 113a of the first controller 11. FIG.

2A, 2B, and 2C are schematic diagrams for explaining the flow of differential reprogramming executed for the product software 113a of the first controller 11. FIG. As shown in FIGS. 2A, 2B, and 2C, in the differential repro, rewriting of the product software 113a proceeds in units of blocks (one chunk of data). The size of the block is appropriately determined according to the specifications of the control device 1 . For example, the size of one block is 32 kBytes.

2A, 2B, and 2C, for the sake of convenience, each block is shown as The blocks are named 1st block, 2nd block, . . . , nth block. The number of blocks is n, where n is any integer greater than or equal to 1. Further, each block (a block of data) that constitutes the existing product software 113a is represented by, for example, "existing data (nth block)" using the previous block name.

As shown in FIG. 2A, difference data is first transmitted from the rewriting device 2 . Here, the difference data is a program newly prepared for rewriting the existing product software 113a (existing program) possessed by the first controller 11 and the existing product software 113a (existing program) possessed by the first controller 11. is the differential data of In this embodiment, the difference data is also in block units. Information indicating which block the difference data belongs to may be included in the difference data as, for example, header information.

Note that the differential data may be transmitted from the rewriting device 2 block by block. However, a plurality of blocks of difference data may be collectively transmitted from the rewriting device 2 . In addition, there may be blocks that do not need to be rewritten among the blocks that constitute the existing product software 113a. It is preferable that the rewriting device 2 does not transmit differential data to such blocks. As a result, the repro time can be shortened.

When a plurality of blocks of differential data for rewriting with existing data exist, the processing shown in FIGS. 2A, 2B, and 2C is performed for each block. Each block is processed in the order of FIGS. 2A, 2B, and 2C. The processes shown in FIGS. 2A to 2C are repeated until all blocks that need to be rewritten have been processed.

In FIG. 2A, more specifically, the difference data for the first block (difference data (first block)) is received in the first controller 11, and the existing data (first block) is to be rewritten. The existing data (first block) stored in the first nonvolatile memory 113 is read, and the first RAM 112 is used as a generation area based on the existing data (first block) and the differential data (first block). New data (first block) is generated. The new data (first block) is data obtained by rewriting the existing data (first block) using the differential data (first block).

As shown in FIG. 2B, when new data (first block) is generated, existing data (first block) stored in first non-volatile memory 113 is erased. Note that erasing existing data (first block) requires generation of new data (first block), and cannot be erased until the generation of new data is completed. After erasing the existing data (first block) is completed, the new data (first block) generated on the first RAM 112 is written to the first non-volatile memory 113 as shown in FIG. 2C. This completes the rewriting of data for one block. The above process is repeated for all blocks that require rewriting, and the reprogramming process is completed.

(2-3. Difference Repro of Product Software Owned by Second Controller)
Next, reprogramming of the product software 123a possessed by the second controller 12 will be described. For this reprogramming, differential reprogramming is used as in the case of the first controller 11 . The differential reprocessing is performed by connecting the control device 1 and the rewriting device 2 and using the reprocessing software 123 b stored in the second non-volatile memory 123 while using the functions of the first controller 11 .

As described above, in this embodiment, the capacity of the second RAM 122 is small, and the second controller 12 cannot independently perform differential reprogramming for reprogramming the product software 123a that it owns. For this reason, the first RAM 112 of the first controller 11 is used for difference repro of the product software 123a of the second controller 12. FIG. Hereinafter, the difference reprocessing of the product software 123a of the second controller 12 will be described on the assumption that the control device 1 recognizes that the reprocessing is targeted to the product software 123a of the second controller 12. .

FIG. 3 is a flow chart showing the flow of differential repro that is executed for the product software 123a that the second controller 12 has. In the difference reprocessing, the rewriting of the product software 123a proceeds in units of blocks (one chunk of data) as in the case of the difference reprocessing of the product software 113a possessed by the first controller 11. FIG. FIG. 3 is a flowchart specifically showing the flow of rewriting processing for one block.

4A, 4B, and 4C are schematic diagrams for explaining the flow of differential reprogramming executed for the product software 123a of the second controller 12. FIG. In FIGS. 4A, 4B, and 4C, for the sake of convenience, each block has a Names such as 1st block, 2nd block, . . . , nth block are given. The number of blocks is n, where n is any integer greater than or equal to 1. Further, each block (a block of data) that constitutes the existing product software 123a is represented by, for example, "existing data (nth block)" using the previous block name.

As shown in FIG. 3, first, the first controller 11 receives difference data necessary for rewriting existing data from the rewriting device 2 (external) (step S1). Here, the difference data is a program newly prepared for rewriting the existing product software 123a (existing program) possessed by the second controller 12 and the existing product software 123a (existing program) possessed by the second controller 12. is the differential data of Specifically, the differential data in step S1 is differential data for one block. As in the case of differential repro in the first controller 11, the first controller 11 may collectively receive differential data for a plurality of blocks. However, even in this case, the processing shown in FIG. 3 is performed for each block.

Note that, in the example shown in FIG. 4A, the first controller 11 creates the first block necessary for rewriting the existing data (first block) constituting the product software 123a already stored in the second nonvolatile memory 123. Difference data (difference data (first block)) is received.

Upon receiving the difference data, the first controller 11 requests the second controller 12 to transmit the existing data stored in the second nonvolatile memory 123 (step S2). Specifically, the first controller 11 requests transmission of existing data of a block (one block worth) corresponding to the block of the received difference data, among the plurality of blocks constituting the existing product software 123a.

Existing data stored in the second non-volatile memory 123 is transmitted from the second controller 12 to the first controller 11 at the request of the first controller 11 (step S3). Specifically, from the second controller 12 to the first controller 11, among the plurality of blocks constituting the existing product software 123a, existing blocks (for one block) corresponding to the block of difference data received by the first controller 11 are transferred. Data is sent.

In the example shown in FIG. 4A, the block corresponding to the block of differential data received by the first controller 11 is the first block, and the existing data (first block) is transferred from the second controller 12 to the first controller 11. has been sent.

When the existing data is received from the second controller 12, the first controller 11 issues to the second controller 12 an instruction to erase the previously transmitted one block of existing data (step S4). A specific example of the erase command is shown in FIG. 4B. In the example shown in FIG. 4B, a command to erase existing data (first block) is issued from the first controller 11 to the second controller 12 .

When the existing data is received from the second controller 12 in the first controller 11, new data is generated based on the existing data and the difference data using the first RAM 112 as a generation area (step S5). The new data is data obtained by rewriting the existing data (one block) by using the difference data (one block). Note that the existing data is the data transmitted from the second controller 12 in step S3. Also, the difference data is the data received in step S1. In this embodiment, the new data generation start process is configured to be started after the erasing process in step S4, but may be started at the same time as step S4 or before step S4.

Upon receiving the erase command from the first controller 11, the second controller 12 stores the same existing data as the existing data transmitted to the first controller 11 in step S3) in the second nonvolatile memory 123. A process of erasing the existing data is performed (step S6). In the example shown in FIG. 4B, a process of erasing the existing data (first block) stored in the second nonvolatile memory 123 is performed.

Note that, in the present embodiment, the process of generating new data using the first RAM 112 (step S5) and the process of erasing existing data in the second nonvolatile memory 123 (step S6) are performed in parallel. By performing the two processes in parallel in this way, it is possible to shorten the time required for the repro process. Differential data may be compressed or encrypted. For this reason, processing for generating new data using differential data requires decompression processing, compounding processing, and the like. As a result, it takes a certain amount of time to generate new data. Also, the erasing process takes a certain amount of time to erase data in units of blocks. Therefore, by performing these two processes in parallel, it is possible to effectively shorten the processing time of the repro process.

Further, in the present embodiment, the second controller 12 is configured to wait for an instruction from the first controller 11 to perform the process of erasing the existing data, but the present invention is not limited to this. For example, when the second controller 12 transmits the existing data for generating new data to the first controller 11 (when the process of step S3 is completed), the process of erasing the existing data may be started. .

When new data is generated in the first controller 11, the new data is transmitted from the first controller 11 to the second controller 12 (step S7). The new data transmitted from the first controller 11 to the second controller 12 is written in the second nonvolatile memory 123 after erasing the existing data in the second nonvolatile memory 123 (after the process of step S6) (step S8). . This completes the rewriting of data for one block. The processing from step S1 to step S8 described above is repeated for all blocks that need to be rewritten, and the reprogramming processing is completed.

Note that in the example shown in FIG. 4C, new data (first block) generated by the first controller 11 is written to the second nonvolatile memory 123 as data to replace the existing data (first block).

As can be seen from the above description, in the control device 1, the difference data necessary for rewriting the existing data stored in the second nonvolatile memory 123 is sent to the first controller 11 from the outside of the device 1 (rewriting device 2). When transmitted, the first RAM 112 is used as a generation area for new data generated using the existing data and the difference data. By configuring in this way, it is possible to reduce the capacity of the second RAM 122 of the second controller 12 and perform differential reprocessing on the product software 123a of the second controller 12 as well. That is, while the second controller 12 is inexpensive, both the product software 113a of the first controller 11 and the product software 123a of the second controller 12 can be differentially reprocessed.

Specifically, when the first controller 11 receives difference data from the outside (rewriting device 2 ), it requests the second controller 12 to transmit the existing data, and transmits the generated new data to the second controller 12 . . The second controller 12 writes new data to the second nonvolatile memory 123 after erasing the existing data in the second nonvolatile memory 123 . With such a configuration, it is possible to efficiently perform difference reprocessing using the first controller 11 for the product software 123a that the second controller 12 has.

Further, as described above, in the present embodiment, the communication speed between the first controller 11 and the second controller 12 is faster than the communication speed between the outside (rewriting device 2) and the first controller 11. is. For this reason, although the product software 123a possessed by the second controller 12 is reprogrammed using the first RAM 112 of the first controller 11 to perform differential reprogramming, new data is reprogrammed after erasing all data. The repro process can be completed in a short time compared to the case where all repros for writing are performed.

<4. Notes, etc.>
Various modifications can be made to the various technical features disclosed in this specification without departing from the gist of the technical creation in addition to the above-described embodiments. That is, the above embodiments should be considered as examples in all respects and not restrictive, and the technical scope of the present invention is not defined by the description of the above embodiments, but by the scope of claims. All changes that come within the meaning and range of equivalency of the claims are to be understood. In addition, the multiple embodiments and modifications shown in this specification may be implemented in appropriate combinations within a possible range.

In the above description, only one second controller 12 is communicably connected to the first controller 11, but this is an example. The present invention can also be applied to a configuration in which a plurality of second controllers 12 are communicably connected to the first controller 11 . Even with such a configuration, differential reprocessing using the first RAM 112 can be performed when performing reprocessing of an existing program possessed by each second controller 12 .

The present invention can also be applied to a configuration in which a third controller is communicably connected to the second controller 12 communicably connected to the first controller 11 . In this configuration, a configuration using the first RAM 112 or a configuration using the second RAM 122 may be used when performing repro processing of an existing program possessed by the third controller. In the latter case, the second RAM 122 needs to have a capacity that allows differential reprocessing.

1... Control device 2... Rewriting device (external)
11... First controller 12... Second controller 112... First RAM
122 Second RAM
123 Second nonvolatile memory (nonvolatile memory)

Claims (5)

a first controller having a first RAM;
a second controller provided to communicate with the first controller;
A control device comprising
The second controller is
a second RAM having a capacity smaller than that of the first RAM;
a non-volatile memory in which data can be electrically rewritten;
has
When difference data necessary for rewriting existing data stored in the nonvolatile memory is transmitted from the outside of the device to the first controller, new data is generated using the existing data and the difference data. A control device using the first RAM for a generation area. the first controller requests the second controller to transmit the existing data when receiving the difference data from the outside, and transmits the generated new data to the second controller;
2. The control device according to claim 1, wherein said second controller writes said new data into said non-volatile memory after erasing said existing data in said non-volatile memory. 3. The control device according to claim 1, wherein a process of generating said new data using said first RAM and a process of erasing said existing data in said nonvolatile memory are performed in parallel. 4. The communication speed between the first controller and the second controller is faster than the communication speed between the outside and the first controller, according to any one of claims 1 to 3. Control device. A method for rewriting existing data stored in a non-volatile memory of the second controller in a control device comprising a first controller having a first RAM and a second controller having a second RAM having a capacity smaller than that of the first RAM, comprising:
a step in which the first controller receives difference data necessary for rewriting the existing data from the outside;
transmitting the existing data from the second controller to the first controller;
a step of generating new data based on the existing data and the difference data using the first RAM as a generation area;
writing the new data sent from the first controller to the second controller into the non-volatile memory after erasing the existing data in the non-volatile memory;
A data rewriting method comprising:

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