JP5821788B2 - Electronic control unit - Google Patents

Description

  The present invention relates to a nonvolatile memory in which a control program and an embedded code are written, a storage unit for storing a control program sent from an external device, and a control program written in the nonvolatile memory in accordance with the rewriting program. The present invention relates to an electronic control device including a CPU that rewrites a control program stored in a storage unit.

  Conventionally, for example, as shown in Patent Document 1, a predetermined control target is controlled by executing a control process based on a built-in program and built-in data in a normal state, and when there is a rewrite command from an external device, There has been proposed an electronic control device that executes a rewriting process for rewriting a program or built-in data with a new program or data transmitted from an external device.

JP-A-9-128229

  In the electronic control device disclosed in Patent Document 1, the above-described built-in program and built-in data are written in the memory area. Usually, the size of the memory area is larger than the sum of the sizes of the built-in program and the built-in data, and an embedded code for notifying an error is written in the empty area.

  On the other hand, the electronic control device disclosed in Patent Document 1 does not have information on the size of the built-in program and the built-in data, and the size of the newly rewritten program and data. Therefore, when executing rewrite processing, not only the built-in program and built-in data written to the memory area but also all embedded codes must be erased in order to reliably write the newly written program and data to the memory area. I didn't.

  The embedded code is a code for notifying an error, and the embedded code written in each address is the same. Thus, the embedded code does not depend on the address to be written. Therefore, in the rewriting process, it is only necessary to delete the embedded code as much as the size of the newly rewritten program or data is secured. However, as described above, the electronic control device disclosed in Patent Document 1 does not have information regarding the size of a newly rewritten program or data. Therefore, in order to reliably write a newly written program or data to the memory area, all of the embedded code must be erased, and the embedded code is erased extra. As a result, it took extra time to erase. In addition, when a new program or data is written, it is necessary to write an embedded code at a surplus address, but the writing time is excessive. As described above, there is a problem that rewriting takes time for erasing and writing of an extra embedded code.

  On the other hand, a method of increasing / decreasing the number of embedded codes as necessary after scanning information on the size of the built-in program or built-in data and the size of the newly rewritten program or data can be considered. However, there is a problem that rewriting takes time for the scanning time.

  In view of the above problems, an object of the present invention is to provide an electronic control device with a shortened rewrite time.

  In order to achieve the above object, the present invention provides a nonvolatile memory (50) in which a first control program and an embedded code are written, and a storage unit (30) for storing a second control program sent from an external device. ) And a CPU (70) for rewriting the first control program written in the nonvolatile memory into the second control program stored in the storage unit according to the rewriting program, In addition to the first control program and the embedded code, first end information indicating the end address of the first control program is written in the memory, and in addition to the second control program, the second control program is stored in the storage unit. Second end information indicating the end address is stored, and the rewrite program is stored in the non-volatile memory or storage unit. The information address where each of the first termination information and the second termination information is stored, and the first address of each of the first control program and the second control program are fixed, and the rewrite program includes the first control program, and Based on the erase program for erasing the first termination information, the first termination information, and the second termination information, it is determined whether the termination address of the second control program is the same as the termination address of the first control program. If the end address of both is the same in the determination program and the determination program, the second control program and the second end information are written to the nonvolatile memory. If the end addresses are different, the embedded code is increased or decreased. And a writing program for writing the second control program and the second termination information into the nonvolatile memory. And wherein the door.

  As described above, according to the present invention, the number of embedded codes is increased or decreased by an amount necessary for writing the second control program based on the first termination information and the second termination information. According to this, at the time of rewriting, the rewriting time is shortened compared to the configuration in which all of the embedded code is erased and the configuration in which the size of data to be rewritten is scanned.

  In the present invention, an increase in the number of embedded codes is also described as expressing that the number of embedded codes is increased or decreased. This is not an operation caused by erasing an extra embedded code to rewrite the second control program, but depends on the processing of the CPU (70). If the data stored at a plurality of addresses is a block, the CPU (70) erases the data written in the nonvolatile memory (50) with this block as one unit (hereinafter referred to as a block unit). When the size of a newly written control program is not expressed in units of blocks, a part of the control program is written in one block. In this case, since an address in which the control program is not written in that block becomes empty, it becomes necessary to write an embedded code in this empty address. In order to fill this vacant address, an operation of increasing the embed code is necessary. Incidentally, an empty address is generated even when the data size of the second control program is smaller than that of the first control program. Therefore, even in this case, it is necessary to write an embedded code at a vacant address, and an operation of increasing the embedded code is required.

  Incidentally, the first end information is the end address of the first control program or the data size of the first control program, and the second end information is the end address of the second control program or the data of the second control program. Size.

It is a block diagram showing a schematic structure of an electronic control unit concerning a 1st embodiment. It is a conceptual diagram which shows the data memorize | stored in memory. It is a flowchart which shows a rewriting process. It is a flowchart which shows a rewriting process. It is a conceptual diagram which shows the data memorize | stored in the non-volatile memory before the rewriting process start. FIG. 6 is a conceptual diagram showing a state where a first control program is erased from the nonvolatile memory shown in FIG. 5. FIG. 7 is a conceptual diagram illustrating a state where an embedded code is erased from the nonvolatile memory illustrated in FIG. 6. FIG. 8 is a conceptual diagram illustrating a state in which second termination information and a second control program are written in the nonvolatile memory illustrated in FIG. 7. FIG. 9 is a conceptual diagram illustrating a state in which an embedded code is written in the nonvolatile memory illustrated in FIG. 8. FIG. 6 is a conceptual diagram showing a modified example in a state where the first control program is erased from the nonvolatile memory shown in FIG. 5. It is a conceptual diagram which shows the state by which the 2nd termination | terminus information and the 2nd control program were written in the non-volatile memory shown in FIG. FIG. 12 is a conceptual diagram illustrating a state where an embedded code is written in the nonvolatile memory illustrated in FIG. 11. It is a flowchart which shows the modification of a rewriting process.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
The electronic control device according to the present embodiment will be described based on FIGS. As shown in FIG. 1, the electronic control device 100 includes a transmission / reception controller 10, a volatile memory 30, a nonvolatile memory 50, and a CPU 70 as main parts.

  The transmission / reception controller 10 performs data transmission / reception with the external device 90. Data transmitted from the external device 90 via the transmission / reception controller 10 is received by the CPU 70 and temporarily stored (saved) in the volatile memory 30.

  The volatile memory 30 temporarily stores a control program and termination information sent from the external device 90 via the transmission / reception controller 10. Specifically, the volatile memory 30 is a RAM and corresponds to a storage unit described in the claims. In the present embodiment, the rewriting program sent from the external device 90 is also stored in the volatile memory 30.

  The nonvolatile memory 50 stores a control program, an embedded code, and termination information. Specifically, the nonvolatile memory 50 is a flash memory. In the nonvolatile memory 50, the information address where the termination information is stored and the head address of the control program are fixed.

  The end information is data indicating the end address of the control program, and is the end address of the control program or the data size of the control program. When the termination information is the data size of the control program, the CPU 70 reads the termination information to determine the data size of the control program. On the other hand, when the end information is the end address of the control program, the start address of the control program is fixed as described above, so the CPU 70 reads the start address and the end address, thereby controlling the control program. Determine the data size. The embedded code notifies an error when the CPU 70 reads the code.

  The CPU 70 operates in accordance with the control program written in the nonvolatile memory 50 during normal operation, and rewrites data (control program, embedded code, termination information) written in the nonvolatile memory 50 during rewrite operation. It is.

  The external device 90 transmits a rewrite program, a control program, and termination information to the electronic control device 100. The external device 90 first transmits a rewrite program to the electronic control device 100, then transmits termination information to the electronic control device 100, and finally transmits a control program to the electronic control device 100. Therefore, the volatile memory 50 stores a rewrite program, termination information, and a control program.

  Next, a rewriting process that is a rewriting of data written in the nonvolatile memory 50 will be described with reference to FIGS. In order to simplify the description, in the following, the control program stored in the non-volatile memory 50 is the first control program, and the control program sent from the external device 90 for rewriting is the second control program. It shows. Further, the end information of the first control program is referred to as first end information, and the end information of the second control program is referred to as second end information. In FIGS. 6 to 8, empty areas (addresses where no data is written) are indicated by dot hatching.

  As shown in FIGS. 2 and 5, the first termination information, the first control program, and the embedded code are written in the nonvolatile memory 50 before the rewriting process is performed. On the other hand, the volatile memory 30 does not store data related to the rewrite process, and the CPU 70 is in a normal operation state. When the rewrite program is transmitted from the external device 90, the rewrite program is stored in the volatile memory 30, and is read by the CPU 70, the CPU 70 shifts from the normal operation state to the rewrite operation state.

  The rewrite program includes an erase program, a determination program, and a write program, and the CPU 70 performs a rewrite process according to these programs. The erasing program includes a first control program and a command for erasing the first termination information. The determination program includes a command for determining whether the end address of the second control program is the same as the end address of the first control program based on the first end information and the second end information. The write program writes the second control program and the second end information to the non-volatile memory 50 when both end addresses are the same in the determination program, and increases or decreases the embedded code when both end addresses are different. And a command to write the second control program and the second termination information into the nonvolatile memory 50. The determination program also includes a command for determining whether or not there is a free area in the nonvolatile memory 50 after the second control program is written to the nonvolatile memory 50.

  Incidentally, the memory size of the volatile memory 30 is smaller than the size of data necessary for the rewriting process. Therefore, it is necessary to sequentially store data necessary for the rewriting process in the volatile memory 30 when the data is used. However, regarding this point, it is sufficient that the second termination information is stored in the volatile memory 30 together with the rewriting program at the timing when the second termination information is necessary (first read processing S20 described later). In describing the electronic control device 100 according to the present invention, there is no particular problem. Therefore, in order to simplify the description, it is assumed that all data necessary for the rewriting process is stored in the volatile memory 30 in the rewriting process (see FIG. 2).

  In the rewriting process, the CPU 70 performs the processes shown in FIGS. 3 and 4 and rewrites the data stored in the nonvolatile memory 50 as shown in FIGS.

  As shown in FIG. 6, the CPU 70 first erases the first control program at the beginning of the rewriting process. The above is the first erasing process S10.

  After the first erasing process S <b> 10, the CPU 70 reads the first termination information stored in the information address of the nonvolatile memory 50 and reads the second termination information from the volatile memory 30. The above is the first reading process S20.

  After the first read process S20, the CPU 70 determines whether or not the end address of the second control program is the same as the end address of the first control program based on the first end information and the second end information. Specifically, the second control program determines whether or not the data size is larger than that of the first control program. The above is the first determination process S30.

  When it is determined in the first determination process S30 that the second control program has a data size larger than that of the first control program, the CPU 70 writes the embedded control code as shown in FIG. Erase as much as necessary. The above is the second erasing process S40. After the second erasing process S40, the CPU 70 proceeds to the process S50 shown in FIG.

  On the contrary, if it is determined in the first determination process S30 that the second control program has a smaller data size than the first control program, the CPU 70 does not perform the second erasure process S40, The process proceeds to process S50 shown in FIG.

  After the process S30 or the process S40, the CPU 70 erases the first termination information stored in the information address of the nonvolatile memory 50. The above is the third erasing process S50.

  After the third erasing process S50, the CPU 70 reads the second termination information stored in the volatile memory 30 and writes it to the information address. The above is the first writing process S60.

  After the first write process S60, the CPU 70 reads the second control program stored in the volatile memory 30 and writes it in the nonvolatile memory 50 as shown in FIG. The above is the second writing process S70.

  After the second write process S70, the CPU 70 determines whether or not there is a free area in the nonvolatile memory 50. The above is the second determination process S80.

  In the second determination process S80, when it is determined that there is a free area in the nonvolatile memory 50 as shown in FIG. 8, the CPU 70 writes an embedded code in the free area as shown in FIG. The above is the third writing process S90. After the third write process S90, the CPU 70 ends the rewrite process.

  On the other hand, if it is determined in the second determination process S80 that there is no free space in the nonvolatile memory 50, the CPU 70 ends the rewrite process without performing the third write process S90.

  Through the above processing, rewriting of the nonvolatile memory 50 is completed. The processes S10 and S50 are performed according to the erase program, the processes S20, S30, and S80 are performed according to the determination program, and the processes S40, S60, S70, and S90 are performed according to the write program.

  Next, functions and effects of the electronic control apparatus 100 according to the present embodiment will be described. As described above, the number of embedded codes is increased or decreased by an amount necessary for writing the second control program based on the first termination information and the second termination information. According to this, at the time of rewriting, the rewriting time is shortened compared to the configuration in which all of the embedded code is erased and the configuration in which the size of data to be rewritten is scanned.

  In the present embodiment, it is determined in steps S80 and S90 whether or not there is an empty area in the nonvolatile memory 50. If there is, an embedded code is written in the empty area. This depends on the processing of the CPU 70 as well as the operation that occurs because the extra embedded code is erased to rewrite the second control program in the second erasure processing S40. If the data stored at a plurality of addresses is a block, the CPU 70 erases the data written in the nonvolatile memory 50 with this block as one unit (hereinafter referred to as a block unit). When the size of the second control program to be newly written is not expressed in units of blocks, a part of the second control program is written in one block. In this case, since an address in which the second control program is not written in the block becomes empty, it is necessary to write an embedded code in the empty address. In order to fill in this vacant address, it is necessary to determine whether or not there is an empty area in the nonvolatile memory 50 in steps S80 and S90. If there is, an operation of writing an embedded code in the empty area is required. It is. Incidentally, even when the data size of the second control program is smaller than that of the first control program, an empty area is generated. Therefore, even in this case, the embedded code must be written in the empty area, and an operation of increasing the embedded code is required.

  Further, in the present embodiment, FIG. 7 shows the state of the nonvolatile memory 50 in a state in which a part of the embedded code originally stored in the nonvolatile memory 50 is erased through the second erasing process S40. . On the other hand, FIG. 10 shows the nonvolatile memory 50 in a state where the embedded code originally stored in the nonvolatile memory 50 is not erased without passing through the second erasing process S40. When the data size of the second control program is smaller than that of the first control program, the CPU 70 writes the second termination information and the second control program into the nonvolatile memory 50 as shown in FIG. It is determined whether or not there is a free area in the memory 50. If the CPU 70 determines that there is a free area in the nonvolatile memory 50, the CPU 70 writes an embedded code in the free area as shown in FIG. This free space is caused by the difference in data size between the first control program and the second control program, and is not dependent on the processing of the CPU 70 described above. For convenience of explanation, FIG. 6 and FIG. 10 are distinguished from each other, but FIG. 6 and FIG. 10 are substantially the same drawings. 6 shows data written in the nonvolatile memory 50 immediately after the first erasing process S10, and FIG. 10 shows a nonvolatile memory immediately before the third erasing process S50 is performed without performing the second erasing process S40. 50 shows the data written to 50.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In the present embodiment, an example is shown in which the control program and the termination information are independent. However, a configuration in which termination information is included in the control program can also be adopted. In this case, as shown in FIG. 13, the CPU 70 performs a second reading process S100 for reading the first termination information before performing the process S10. And after process S10, CPU70 performs process S110, S120 instead of process S20. That is, the CPU 70 performs a third read process S110 for reading the second termination information included in the second control program of the volatile memory 30, and during the reading, a part of the second control program is transferred to the nonvolatile memory 50. A fourth writing process S120 is performed to perform the process of writing to the. When the second termination information is acquired, the CPU 70 proceeds to the process S30, and performs the rewriting process to the nonvolatile memory 50 by performing the processes S30 to S90 shown in the first embodiment. As described above, when reading the second termination information, a part of the second control program is written to the nonvolatile memory 50, so that the nonvolatile memory 50 is nonvolatile at the same speed as the rewrite processing shown in the first embodiment. Rewriting of the memory 50 is performed. In the second write process S70, the remainder of the second control program that could not be written in the fourth write process S120 is written to the nonvolatile memory 50. Further, termination information included in the control program is written in the information address of the nonvolatile memory 50.

  In the present embodiment, an example in which the rewriting program sent from the external device 90 is stored in the volatile memory 30 is shown. However, a configuration in which the rewriting program stored in the nonvolatile memory 50 is stored in the volatile memory 30 can be adopted.

30 ... Volatile memory 50 ... Nonvolatile memory 70 ... CPU
100 ... Electronic control device

Claims (2)

A non-volatile memory (50) in which the first control program and the embedded code are written;
A storage unit (30) for storing the second control program sent from the external device;
A CPU (70) for rewriting a first control program written in the nonvolatile memory according to a rewrite program into a second control program stored in the storage unit;
In the nonvolatile memory, in addition to the first control program and the embedded code, first termination information indicating a termination address of the first control program is written,
The storage unit stores second termination information indicating a termination address of the second control program in addition to the second control program,
The rewrite program is stored in the nonvolatile memory or the storage unit,
In the non-volatile memory, information addresses where the first termination information and the second termination information are stored, respectively, and the first addresses of the first control program and the second control program are fixed,
The rewriting program includes
An erasing program for erasing the first control program and the first termination information;
A determination program for determining whether a termination address of the second control program is the same as a termination address of the first control program based on each of the first termination information and the second termination information;
In the determination program, when both end addresses are the same, the second control program and the second end information are written to the nonvolatile memory, and when the end addresses are different, the embedded code is increased or decreased. And a writing program for writing the second control program and the second termination information into the nonvolatile memory. The first termination information is a termination address of the first control program or a data size of the first control program.
The electronic control device according to claim 1, wherein the second termination information is a termination address of the second control program or a data size of the second control program.

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