JP2012022432A - Embedded control device, developing method for embedded control device, and embedded control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an embedded control device which can easily adjust fixed-value data stored in a read-only memory by using a processing unit having general structure.SOLUTION: An embedded control device read-outs fixed-value data stored in a read-only memory to expand the fixed-value data into a random access memory, refers to the fixed-value data on the random access memory to execute control action.

Description

  The present invention relates to an embedded control device that controls an electronic device.

  A control program describing the control operation of the embedded control device is stored in the nonvolatile storage device. Further, fixed value data such as a threshold value used in the control program is also stored in a storage area separate from the control program. Since these programs and fixed value data are considered to normally not change after the embedded controller is shipped to the market, it is stored in a read-only memory such as a ROM (Read Only Memory). There is.

  In the process of developing the embedded control device, it may be necessary to adjust the fixed value data in accordance with the characteristics of the electronic device to be controlled separately from the control program itself. At this time, if the fixed value data is stored in the read-only memory, the process of correcting the source file defining the fixed value data and rewriting all the storage areas storing the fixed value data is performed from the beginning. There must be. This is because the data stored in the read-only memory cannot be individually rewritten as in units of files, and must be rewritten in a batch to a certain extent. Therefore, even if it is an operation that only requires correction of fixed value data, it takes a considerable amount of time and hinders a rapid development operation.

  As a technique for solving the above problem, there is a ROM emulation. In this method, fixed value data in the ROM is developed on a RAM (Random Access Memory) so that the fixed value data can be corrected on the RAM. Since fixed value data is developed on the RAM, it is possible to search for an optimum value while changing the value as needed, and it is not necessary to write to the ROM one by one, so that it is expected to improve development efficiency. .

  Japanese Patent Application Laid-Open No. 2004-228561 describes one method related to ROM emulation. In this document, the microcomputer has a ROM emulation function, and the address on the ROM to be emulated can be automatically replaced with the address on the RAM.

  In the following Patent Document 2, a method using a task table is described. In this document, the changed constant value data is arranged in a non-volatile RAM area, and the task table is changed so as to refer to the newly arranged non-volatile RAM area. Thereby, the same effect as rewriting constant value data can be acquired.

JP 2000-181744 A JP-A-4-259046

  In the technique described in Patent Document 1, it is necessary for the microcomputer to have a ROM emulation function for replacing the address on the ROM with the address on the RAM, and a configuration different from that of a general microcomputer is required.

  In the technique described in Patent Document 2, it is necessary to provide a software structure for managing the reference order using a task table. Further, it is necessary to employ a microcomputer having a nonvolatile RAM area. Therefore, similarly to Patent Document 1, a configuration different from a general embedded control program and a microcomputer is required.

  The present invention has been made to solve the above-described problems, and easily adjusts fixed value data stored in a read-only memory using an arithmetic device having a general configuration. It is an object to obtain an embedded control device capable of performing the above.

  The embedded control device according to the present invention reads fixed value data stored in a read-only memory, develops it in a reading memory, and executes a control operation with reference to the fixed value data in the reading memory.

  The embedded control device according to the present invention executes the control operation with reference to the fixed value data in the reading / reading memory, so that it is not necessary to rewrite values to the read-only memory in order to adjust the fixed value data. Thereby, the work burden of adjusting the fixed value data can be reduced. Further, each memory and the arithmetic unit do not need to have special functions as in the above-mentioned Patent Documents 1 and 2, and thus the above functions can be realized using a general microcomputer.

3 is a functional block diagram of the embedded control device 100 according to Embodiment 1. FIG. It is a figure which shows the mode of each memory when the embedded control apparatus 100 is working. It is a flowchart explaining the initial process when the control program 132 starts operation | movement. FIG. 10 is a functional block diagram of an embedded control device 100 according to a third embodiment. It is a figure which shows the mode of each memory when the embedded control apparatus 100 is working. It is a figure which shows the mode of each memory when the microcomputer 110 receives the power OFF instruction | indication. It is a figure which shows the mode of each memory after the operation | movement of the completion | finish process program 134 is complete | finished.

<Embodiment 1>
FIG. 1 is a functional block diagram of the embedded control device 100 according to Embodiment 1 of the present invention. The embedded control device 100 is a device that controls an electronic device such as an electronic control system of a vehicle, and includes a microcomputer 110, a RAM 120, and a ROM 130. In FIG. 1, the microcomputer 120 is described so as to include the RAM 120 and the ROM 130, but the present invention is not limited to this. For example, the microcomputer 110 may be configured individually.

  The microcomputer 110 is an arithmetic device that controls a control target by executing a control program 132 described later. The RAM 120 is a volatile memory for reading and reading that temporarily stores data and the like necessary in the process of operating the control program 132. The ROM 130 is a read-only nonvolatile memory that stores fixed value data 131 and a control program 132.

  The fixed value data 131 is data that holds a fixed value necessary for the operation of the control program 132 such as threshold data. When the embedded control device 100 is shipped to the market, the value of the fixed value data 131 has already been determined and is not normally changed thereafter, so it is stored in the ROM 130 which is a read-only memory.

  The control program 132 is a software program describing a control operation executed by the embedded control device 100. The control program 132 is described so as to refer to the fixed value data 131 in the course of the control operation. However, the reference address is devised to be described later with reference to FIG.

  In the following, for convenience of explanation, each program such as the control program 132 may be described as an operation subject. However, it is added that the program is actually executed by an arithmetic unit such as the microcomputer 110.

  FIG. 2 is a diagram illustrating a state of each memory when the embedded control device 100 is operating. When the built-in control device 100 is turned on, the microcomputer 110 reads the control program 132 and executes it. The control program 132 reads the fixed value data 131 stored on the ROM 130 and expands it as the fixed value data 121 on the RAM 120 (copy and write the value). Thereafter, the control program 132 refers to the fixed value data 121 on the RAM 120 and executes a control operation.

  In the above description, the control program 132 reads the fixed value data 131 and develops it on the RAM 120. However, an initialization program for performing a process for initializing the microcomputer 110 is provided separately. It can also be configured to perform similar processing. The same applies to the following embodiments.

FIG. 3 is a flowchart for explaining an initial process when the control program 132 starts to operate. Hereinafter, each step of FIG. 3 will be described.
(FIG. 3: Steps S300 to S301)
When the power supply of the embedded control device 100 is turned on, this operation flow is started. The embedded control device 100 resets and initializes the microcomputer 110.

(FIG. 3: Steps S302 to S303)
The embedded control device 100 sets a register (not shown) necessary for the control program 132 to operate. Also, the entire storage area of the RAM 120 is initialized.
(FIG. 3: Step S304)
The microcomputer 110 executes the control program 132. The control program 132 acquires the start address and the end address at which the fixed value data 121 is to be written on the RAM 120.

(FIG. 3: Step S305)
The control program 132 acquires a head address for reading the fixed value data 131 from the ROM 130.
(FIG. 3: Steps S304 to S305: Supplement)
The start address value and the end address value acquired in steps S304 to S305 may be incorporated as part of the control program 132, for example, or may be fixedly stored in an appropriate storage area on the ROM 130. Good.

(FIG. 3: Step S306)
The control program 132 accesses the address obtained in step S305 (or step S308 described later), and sequentially reads the fixed value data 131 stored in the ROM 130. Next, the control program 132 accesses the address obtained in step S304 (or step S309 described later), and writes the fixed value data 131 read from the ROM 130 into the RAM 120 as the fixed value data 121.
(FIG. 3: Step S306: Supplement)
In this step, it is not always necessary to write the entire fixed value data 131 to the RAM 120 at a time, and it may be written in a plurality of times. In this case, steps S306 to S309 are repeated a plurality of times.

(FIG. 3: Step S307)
The control program 132 determines whether or not the address to which the fixed value data 121 is written in the RAM 120 has reached the end address acquired in step S304. If the end address has been reached, this operation flow is terminated, and thereafter the control operation is executed. If the end address has not been reached, the process proceeds to step S308.
(FIG. 3: Steps S308 to S309)
The control program 132 increases the read source address for reading the fixed value data 131 from the ROM 130 by a specified amount. Further, the control program 132 increases the write destination address for writing the fixed value data 121 in the RAM 120 by a specified amount. After incrementing each address, the process returns to step S306 and the same processing is repeated.

  The initial process when the control program 132 starts operation has been described above. When the initial processing is completed, the control program 132 performs a control operation while referring to the fixed value data 121 on the RAM 120 instead of the fixed value data 131 on the ROM 130.

<Embodiment 1: Summary>
As described above, the embedded control apparatus 100 according to the first embodiment expands the fixed value data 131 stored in the ROM 130 as the fixed value data 121 on the RAM 120, and performs a control operation while referring to the fixed value data 121. To implement. As a result, the control program 132 can be executed while changing the fixed value data 121 on the RAM 120. Therefore, it is not necessary to rewrite the ROM 130 every time the value of the fixed value data 131 is adjusted, greatly increasing the burden of development work. Can be reduced.

  In the first embodiment, when the fixed value data 121 on the RAM 120 is to be changed, the fixed value data 121 is connected to the microcomputer 110 and the RAM 120 via a RAM rewriting program or the like different from the control program 132, and the fixed value data 121 is set to a desired value. Can be rewritten. This RAM rewriting program can be executed, for example, on a development work computer outside the embedded control apparatus 100.

  When the ROM 130 is rewritten, the operation of the ROM 130 must be completely terminated. However, when the data in the RAM 120 is rewritten, the RAM 120 may be in operation. That is, since the fixed value data 121 can be rewritten to an arbitrary value even while the control program 132 is being executed, the method according to the present invention is advantageous from this viewpoint.

<Embodiment 2>
In the second embodiment of the present invention, a process of developing the embedded control device 100 described in the first embodiment will be described. A description of the matters already described in the first embodiment will be omitted as appropriate.
(Development process 1: Processing to expand fixed value data)
The control program 132 needs to expand the fixed value data 131 on the RAM 120 by executing the initial operation described with reference to FIG. 3 of the first embodiment before starting the control operation. When the developer develops the embedded control device 100, the developer needs to develop the operation flow of FIG. 3 as a part of the function of the control program 132.

(Development process 2: Control action using expanded fixed value data)
The developer develops a control process so that the control operation is performed using the fixed value data 131. Specifically, work such as associating fixed value data referred in the control program 132 with the control program 132 on the development support tool of the embedded control program is performed. In general, in this step, the development support tool generates address table data describing the storage destination address of the fixed value data 131 on the ROM 130.
(Development process 2: Control action using expanded fixed value data: supplement)
The built-in control program development support tool seems to assume that fixed value data is arranged on the ROM 130 in which the control program 132 is stored. For this reason, the storage address on the ROM 130 is described in the address table data generated in this step. The control program 132 reads the fixed value data from the address described in the address table data.

(Development process 3: Rewrite the address table)
The address table generated in the development process 2 describes addresses on the ROM 130. This address is required when the fixed value data 131 is read and written to the RAM 120. On the other hand, when the control program 132 performs a control operation, it is necessary to specify an address on the RAM 120. Therefore, while the address table used for implementing the operation flow of FIG. 3 is left as it is, the address table describing the address indicating the fixed value data 131 on the ROM 130 is rewritten to the address indicating the fixed value data 121 on the RAM 120. There is a need.
(Development process 4: Write to ROM 130)
The developer writes the control program 132, fixed value data 131, and address table developed in the above process in the ROM 130.

(Development process 5: Adjust fixed value data 121)
The developer executes the RAM rewriting program on the development work computer outside the embedded control apparatus 100, and causes the microcomputer 110 to execute the control program 132 while rewriting the fixed value data 121 developed on the RAM 120. . The developer searches the value of the fixed value data 121 most suitable for the control target while repeating this operation.
(Development process 6: Write to ROM 130)
The developer writes the adjusted fixed value data 121 in the ROM 130 again. Through the above steps, the development of the embedded control device 100 is completed.

<Embodiment 2: Summary>
As described above, in the second embodiment, the process of developing the embedded control device 100 has been described. In the development process 5, the developer can modify the fixed value data 121 on the RAM 120, so that it is not necessary to perform the development process 4 or 6 every time the fixed value data is modified. Thereby, the efficiency of development work can be improved.

<Embodiment 3>
In the third embodiment of the present invention, a method of further developing the method described in the first and second embodiments and automatically reflecting the fixed value data 121 corrected on the RAM 120 onto the ROM 130 will be described. Except for the configuration relating to automatic reflection, the configuration is the same as in the first and second embodiments.

  FIG. 4 is a functional block diagram of the embedded control device 100 according to the third embodiment. In the third embodiment, in addition to the configurations described in the first and second embodiments, the ROM 130 newly stores an end processing program 134 and a fixed value data update program 133. Other configurations are the same as those in the first and second embodiments.

  The termination processing program 134 is a program that describes termination processing to be performed when the microcomputer 110 is terminated. The microcomputer 110 is configured to execute the end processing program 134 when receiving an instruction to turn off the power.

  The fixed value data 133 is a program describing a process for writing back the fixed value data 121 developed on the RAM 120 to the ROM 130. Details will be described later with reference to FIGS.

  FIG. 5 is a diagram illustrating a state of each memory when the embedded control device 100 is operating. When the built-in control device 100 is turned on, the microcomputer 110 reads the control program 132 and executes it. The control program 132 expands the fixed value data 131 on the RAM 120 as in FIG. 2 of the first embodiment.

  FIG. 6 is a diagram showing the state of each memory when the microcomputer 110 receives a power-off instruction. When the microcomputer 110 receives an instruction to turn off the power, the microcomputer 110 executes a termination processing program 134 stored in the ROM 130. The end processing program 134 copies the fixed value data update program 133 that is also stored in the ROM 130 onto the RAM 120. For convenience, the fixed value data update program copied onto the RAM 120 is referred to by reference numeral 123. The termination processing program 134 executes other termination processing as appropriate.

  FIG. 7 is a diagram illustrating the state of each memory after the operation of the termination processing program 134 is terminated. The end processing program 134 activates the fixed value data update program 123 stored on the RAM 120 when the end processing ends.

  The fixed value data update program 123 completes the operation of the ROM 130 and then writes back the fixed value data 121 on the RAM 120 as the fixed value data 131 on the ROM 130. As a result, the value of the fixed value data 121 corrected on the RAM 120 can be reflected in the fixed value data 131 on the ROM 130.

  The reason why the ROM 130 is first terminated before the fixed value data update program 123 writes back the fixed value data 121 is that data cannot be written when the ROM 130 is operating.

  In the third embodiment, the end processing program 134 and the fixed value data update program 133 have been described as programs different from the control program 132. However, any two or more of these programs may be configured integrally. it can.

<Embodiment 3: Summary>
As described above, according to the embedded control apparatus 100 according to the third embodiment, the fixed value data 121 is automatically written to the ROM 130 by the fixed value data update program 123 on the RAM 120 when the microcomputer 110 is terminated. Returned. As a result, the work of rewriting the fixed value data 121 corrected on the RAM 120 into the ROM 130 can be omitted, so that the development work can be made more efficient.

  Further, according to the third embodiment, the process of writing the fixed value data 121 back to the ROM 130 is automatically performed, so that the possibility of making an error such as writing an incorrect value to the ROM 130 is reduced, and as a result The quality and performance of the embedded control device 100 can be improved.

  When the configuration described in the third embodiment is adopted, in the process of developing the embedded control device 100, the process of developing the end processing program 134 and the fixed value data update program 133 is newly increased. However, this development process only needs to be performed once. On the other hand, the development process 6 described in the second embodiment can be omitted. Since the development process 6 occurs every time the fixed value data 131 is adjusted for a new control target, it seems that the effect of omitting this is great.

<Embodiment 4>
In the above first to third embodiments, the control program 132 is configured to execute the control operation with reference to the fixed value data 121 on the RAM 120 in consideration of the efficiency of the development process. However, it is not necessary to use the fixed value data 121 after adjusting the fixed value data 131.

  Therefore, when the embedded control device 100 is shipped to the market, the process of expanding the fixed value data 131 into the RAM 120 is deleted, and the control program 132 refers to the fixed value data 131 and executes the control operation again. The control program 132 may be reconfigured.

  100: Embedded control device, 110: Microcomputer, 120: RAM, 130: ROM, 131: Fixed value data, 132: Control program, 133: Fixed value data update program, 134: End processing program.

Claims (8)

An embedded control device for controlling an electronic device,
A control program describing an operation for controlling the electronic device;
A read-only memory that stores the control program and fixed value data used in the control program in a read-only manner;
Reading memory that stores data for both reading and writing;
An arithmetic unit that executes the control program to control the electronic device;
With
The control program is
A process of reading the fixed value data from the read-only memory and expanding it into the reading memory;
Processing to execute the operation using the fixed value data developed in the reading memory;
Is described,
The computing unit is
The embedded control apparatus, wherein the fixed value data is read from the read-only memory according to a description of the control program, developed in the reading memory, and the operation is executed using the fixed value data. The read-only memory is
An end processing program describing an end processing to be executed when the operation of the arithmetic unit is ended;
A fixed value data update program describing a process of writing the fixed value data developed on the reading memory to the read-only memory;
Remember
The termination processing program further includes
A process for copying the fixed value data update program to the reading memory, a process for terminating the operation of the read-only memory, and a process for starting the fixed value data update program;
The computing unit is
When receiving a signal to terminate the operation of the arithmetic unit,
After the execution of the termination processing program and copying the fixed value data update program to the reading memory, the read-only memory is terminated.
The embedded control device according to claim 1, wherein the fixed value data update program copied to the reading memory is executed to write the fixed value data developed on the reading memory to the read-only memory. . A control program describing the operation of controlling the electronic device;
A read-only memory that stores the control program and fixed value data used in the control program in a read-only manner;
Reading memory that stores data for both reading and writing;
An arithmetic unit that executes the control program to control the electronic device;
A method for developing an embedded control device comprising:
In the control program,
A process of reading the fixed value data from the read-only memory and expanding it into the reading memory;
Processing to execute the operation using the fixed value data developed in the reading memory;
Steps to describe
Writing the control program and fixed value data used in the control program to the read-only memory;
An embedded control device development method characterized by comprising: In the step of describing the process of executing the operation using the fixed value data in the control program,
The read source address of the fixed value data set as an address on the read only memory is replaced with a write destination address where the control program develops the fixed value data on the read memory. Item 4. A method for developing an embedded control device according to Item 3. Adjusting the fixed value data developed in the reading memory using a reading memory rewriting program different from the control program;
Executing the control program using the adjusted fixed value data;
Searching the fixed value data suitable for controlling the electronic device;
The embedded control device development method according to claim 3, wherein the embedded control device is developed. An end processing program describing an end processing to be executed when the operation of the arithmetic unit is ended;
A fixed value data update program for writing the fixed value data developed on the reading memory into the read-only memory;
Has the steps to develop and
In this step, in the end processing program,
A process for copying the fixed value data update program to the reading memory, a process for terminating the operation of the read-only memory, and a process for starting the fixed value data update program are described, and when the operation unit finishes the operation, 6. The end value processing program and the fixed value data update program are executed by the arithmetic unit so that the fixed value data developed on the reading memory is written to the read-only memory. A method for developing an embedded control device according to any one of the preceding claims. A control program describing an operation for controlling an electronic device,
A read-only memory that stores the control program and fixed value data used in the control program in a read-only manner;
Reading memory that stores data for both reading and writing;
An arithmetic unit that executes the control program to control the electronic device;
Configured to be executed on an embedded control device with
The control program is stored in the calculation unit.
A process of reading the fixed value data from the read-only memory and expanding it into the reading memory;
Processing to execute the operation using the fixed value data developed in the reading memory;
A built-in control program characterized in that it describes a process for executing An end processing program describing an end processing to be executed when the operation of the arithmetic unit is ended;
A fixed value data update program describing a process of writing the fixed value data developed on the reading memory to the read-only memory;
Have
The termination processing program is stored in the calculation unit.
It describes a process for copying the fixed value data update program to the reading memory, a process for ending the operation of the read only memory, and a process for starting the fixed value data update program. The embedded control program according to claim 7.

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