JPH11312089A - Electronic control unit - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To enable a program having a memory capacity or more to be stored without additional memory. When a program to be stored exceeds the capacity of a ROM 22 (or a read-only memory) which is an electrically rewritable memory, a part of the program is compressed and stored in the ROM 22; After power is turned on, it is decompressed and expanded in the DRAM 23 for use. All of the compressed programs may be expanded on the DRAM 23 or may be expanded and used for each program to be used. Unnecessary programs are deleted from the DRAM 23 in order to secure a development area on the DRAM 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic control unit for controlling operation using a microcomputer, and more particularly to a program storage method for the electronic control unit.

[0002]

2. Description of the Related Art FIG. 9 is a schematic block diagram of a vehicle-mounted traveling position display device showing an example of a conventional electronic control device. FIG.
In the above, reference numeral 1 denotes a direction sensor, which uses a gyro for detecting a relative running direction of an automobile. Reference numeral 2 denotes a distance sensor that generates a pulse corresponding to the number of rotations of the wheels. Reference numeral 3 denotes various sensor signals such as an ON / OFF signal of a brake switch, a parking switch, and the like, and a power supply voltage monitoring signal. Reference numeral 4 denotes a sensor signal processing unit that processes sensor signals such as an azimuth sensor 1, a distance sensor 2, and various sensor signals 3, and 5 denotes a GPS (Gl).
obal Positioning System) is a receiver that receives and calculates radio waves transmitted from a plurality of satellites to determine the position (latitude and longitude) of a reception point. Reference numeral 6 denotes a CD-ROM drive, which is a CD-ROM 7 on which map data is recorded.
Read map data from. Reference numeral 8 denotes a display / operation unit installed in the vehicle compartment, which includes a map and a current traveling position of the car;
A touch panel 8B having a liquid crystal display 8A for displaying an azimuth and the like and a touch panel 8B disposed on the front surface thereof;
Is provided with a switch for instructing enlargement or reduction of the display map, a switch for instructing a route search, a switch for selecting a destination from the place names displayed on the liquid crystal display 8A, and the like. Reference numeral 9 denotes an apparatus main body, which is arranged in a trunk room or the like.

In the apparatus main body 9, reference numeral 10 denotes a CPU (central processing unit) for performing various calculations, 11 denotes a ROM which is an electrically rewritable memory storing various calculation programs to be executed by the CPU 10, and 12 denotes a direction sensor. 1, distance sensor 2, various sensor signals 3, GPS receiver 5, CD-
DR, which is a rewritable memory for storing data from the ROM drive 6 and the like and calculation results in the CPU 10, etc.
AM and 13 are SRAMs which are backup memories for holding necessary data even when power supply to the apparatus main body 9 is stopped, and 14 is a pattern for characters and symbols displayed on the liquid crystal display 8A. A kanji / font ROM, which is a read-only memory for storing, 15 is an image processor for forming a display image based on map data, current position data of the own vehicle, etc., 16 is map data, current position data output from the CPU 10. And a VRAM 17 which is an image memory for synthesizing kanji and fonts output from the kanji / font ROM 14 such as town names and road names and displaying them on the liquid crystal display 8A. A color signal is output from the RGB conversion circuit 17 to the liquid crystal display 8A. Reference numeral 18 denotes a communication interface, and 19 denotes a runaway monitoring circuit.

Next, the operation of the traveling position display device configured as described above will be described. The output of the azimuth sensor 1 and the output of the distance sensor 2 are transmitted through the sensor processing unit 4 to C
When sent to the PU 10, the CPU 10 calculates the current position of the vehicle, calculates the latitude and longitude of the current position, and corrects the current position based on data from the GPS receiver 5. The map data corresponding to the current position obtained in this manner is read from the CD-ROM 7 by the CD-ROM drive 6, and the map data is read via the communication interface 18 to the DRAM.
12 is stored. A part of the map data stored in the DRAM 12 is read by the CPU 10, converted into image data by the image processor 15, and
Is written to. The image data stored in the VRAM 16 is converted into a color signal by an RGB conversion circuit 17, sent to the liquid crystal display 8A, and a map of a predetermined range centering on the current position is displayed. If the map data read from the DRAM 12 contains character codes and symbol codes, patterns corresponding to these character codes and symbol codes are read from the kanji / font ROM 14 and displayed on the liquid crystal display 8A together with the map. , Etc., and symbols such as school are displayed. Further, the current position displayed on the liquid crystal display 8A is sequentially changed based on the traveling speed and the traveling azimuth sequentially obtained as the vehicle travels.

Next, the flow of processing after the power of the apparatus main body 9 is turned on will be described with reference to FIG. ROM that can be electrically rewritten by the CPU 10 after the device power is turned on.
The program is read from the memory 11, and the memories 12, 13,
Activation and initialization of 14, 16; communication interface 1
8. Initialize the sensor signal processing unit 4, set the runaway monitoring circuit 19, etc. (S21), and then determine whether the device is started up in the normal processing mode or in the upgrade mode (S22). . In the case of the normal mode, the settings necessary for activating the communication interface 18, the sensor signal processing unit 4, and each task are performed (S23). Next, the kernel processing of the installed OS is started (S2).
4) Then, the communication interface 1 according to the operation mode
8. Perform an initialization handler for the system such as the sensor signal processing unit 4 (S25), and finally generate an initial task.
It is activated (S26). Here, the start-up of each peripheral device connected to the communication interface 18 and the sensor signal processing unit 4 is confirmed, tasks that need to be started up at the beginning are generated and started up, and the CD-ROM drive 6 is The loading of resident data is performed via the. In addition, a task that needs to be started up is finally generated and started, and the started task performs a necessary process as the traveling position display device. After that, necessary processing is performed for each task. From this point on, it functions as a traveling position display device. If it is determined in step S22 that the version needs to be upgraded, initialization is performed in that mode (S27), and steps S24 to S26 in the normal mode are performed.
(S2) is performed with the settings for version upgrade.
8) After that, the program in the electrically rewritable ROM 11 is replaced with a new one by version upgrade processing. Thereafter, the processing is sequentially performed from step S21.

[0006]

However, in the above-mentioned conventional electronic control device, if the program to be stored in the ROM 11 exceeds the capacity of the ROM 11 due to the addition of a new function or the like, the ROM 11 is added as a solution. Therefore, there is no other choice but to increase the capacity, and there is a problem that the cost as a product cannot be avoided. The same applies to the read-only ROM 14.

The present invention solves the above-mentioned conventional problems, and provides an electronic control unit capable of storing a program required for processing without increasing the memory even when the program exceeds the capacity of the memory. The purpose is to:

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method for compressing a program even if the program to be stored exceeds the capacity of a read-only memory or an electrically rewritable memory. Then, the program is stored in a memory, and after the power is turned on, the program is decompressed and expanded in a rewritable memory as needed, so that a necessary program can be stored without adding a memory.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention provides an electronic device for controlling the operation using a microcomputer having a rewritable memory and a read-only memory or an electrically rewritable memory. A control unit for storing a compressed program in the read-only memory or the electrically rewritable memory, and decompressing the compressed program when power is turned on to expand the program on the rewritable memory at any time; It is a control device, and by storing a compressed program,
This has the effect of reducing the amount of use of a read-only memory or an electrically rewritable memory.

According to a second aspect of the present invention, a read-only memory or an electrically rewritable memory includes:
2. The electronic control device according to claim 1, wherein both an uncompressed program and a compressed program are arranged, and has an effect that compression or non-compression can be selected according to a program to be executed.

According to a third aspect of the present invention, a program requiring processing at power-on is arranged as an uncompressed program stored in a read-only memory or an electrically rewritable memory. 3. The electronic control device according to claim 2, which has an effect that a necessary program can be instantaneously activated when the power is turned on.

According to a fourth aspect of the present invention, during the processing of the non-compressed program to be executed when the power is turned on, the decompression processing of the compressed program is performed in parallel. An electronic control unit that decompresses a compressed program and expands it to a rewritable memory as needed before processing of the compressed program is required, so that the program can be processed immediately when it becomes necessary. Having.

According to a fifth aspect of the present invention, when a compressed program is used, a necessary program is decompressed and expanded in a rewritable memory, and an unnecessary program can be rewritten as needed. 5. The electronic control device according to claim 1, wherein a development area of the memory which can be rewritten at any time is shared between programs, and a shortage of the development area is compensated. It has the effect of being able to.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. (Embodiment 1) FIG. 1 is a schematic block diagram of an in-vehicle traveling position display device according to an embodiment of the present invention. Elements similar to those of the conventional device shown in FIG. It is. This embodiment is different from the conventional example described above in that
The CPU 20 controls a method of storing a program in a ROM 22 that is an electrically rewritable memory and a DRAM 23 that is a rewritable memory as needed through a compression / decompression unit 21. In the ROM 22,
As shown in FIG. 2, in the conventional example, the ROM
The program A stored in No. 1 is stored in the ROM 22 by compressing the remaining part A-2 by the compression / decompression unit 21 while leaving part A-1 of the program A uncompressed. . As a result, in the present embodiment, even a program that would otherwise be inaccessible unless a memory is additionally provided can be stored without adding a ROM 22 in the present embodiment. When executing the program, as shown in FIG. 3, the compression / decompression unit 21 decompresses (decompresses) the program of the compressed part A-2 stored in the ROM 22 to D
Since the program is developed in the RAM 23, the program can be executed without delay. The CPU 20 can execute the same processing on the kanji / font ROM 14 which is a read-only memory.

In FIG. 2, a non-compressed portion A-1 in which a non-compressed program is arranged includes a hardware initialization program that needs to be processed immediately after power-on, a program for generating and starting a task, and a CD-ROM. A program for loading data from the RAM 7 is provided.
In the compressed part A-2 in which the compression program is arranged, a program as a traveling position display device such as a program for performing a route search to search for a point, an index search program, and a vehicle position display program is arranged in a compressed state. Keep it. By arranging in this way, programs that need to be processed and tasks that need to be processed immediately when the power is turned on can be started with the conventional startup time, and the required programs are decompressed and used after startup. As a result, it is possible to realize the same function as before.

FIG. 4 shows a process after the power is turned on in the present embodiment. In FIG. 3, first, a minimum pre-initialization process required for starting the system is performed (S1). Next, it is determined whether the mode is the upgrade mode or the normal mode (S
2) In the case of the normal mode, initialization and settings required for the processing are performed for each device (S3), and then a kernel boot process is performed (S4). When the kernel is started, an initialization handler depending on the system is performed (S5), and then an initial task, which is a task that needs to be started first, such as a data loading task from the CD-ROM 7, is generated and started. (S6). Next, the loading of the CD, which is the initial task, is performed (S7), and at the same time, the compressed portion A- of the ROM 22 shown in FIG.
2 is executed to decompress and expand the program arranged in the DRAM 23 (S8). Process S8 is a process S
7, the data is read from the CD-ROM 7 at the same time, and the decompression and expansion are completed by the time the data is read out. Finally, display your vehicle position, search for routes,
A task that finally needs to be started, such as an index search, is generated and started (S9). If it is determined in step S2 that version upgrade is required, initialization is performed in that mode (S10), and the same processes as those in steps S4 to S6 in the normal mode are performed with settings for version upgrade (S10).
A) After that, a version upgrade process is performed to replace the program in the ROM 22 with a new one.

In a process S9 in FIG. 4, processes necessary for the actual travel position display device are performed. For example, in the display of the traveling position, the vehicle signal input from the direction sensor 1 and the distance sensor 2 in FIG.
Based on the vehicle position information received by the S receiver 5, a vehicle position display program for displaying the current vehicle position on the liquid crystal display 8A is executed. Further, when the user calls another function, for example, calls the route search function by pressing the touch panel 8B, the DRAM 2
By executing the route search program developed on 3, processing necessary for the route search is performed.

As described above, according to the first embodiment,
A part of the program is compressed and stored in the ROM 22, and when the program is needed, it is decompressed to
23, so that even if the number of programs increases due to the addition of new functions, the capacity of R
It can be stored on the OM 22 and can have functions equivalent to or higher than the conventional one at a lower cost than the conventional electronic control unit.

(Embodiment 2) Next, Embodiment 2 of the present invention will be described. The second embodiment has the same device configuration as the first embodiment, but the processing of the CPU 20 is slightly different, so that only the processing will be described below with reference to FIG. In FIG. 5, the processing from S11 to S
Steps up to 15 are substantially the same as steps S1 to S7 in FIG. 4, and are different from step S16. Processing S16
In, the program to be decompressed is not limited to all of the compressed programs, but is limited to only those which need to be expanded in the DRAM 23 in order to perform processing in the initial stage. FIG. 6 shows this state. The programs arranged in the ROM 22 are a vehicle position display program A, an index search program B, a route search program C, and a voice recognition program D. The display of the own vehicle position is an indispensable function in the traveling position display device, and it is necessary to display the map and the current position of the own vehicle on the map on the liquid crystal display 8A from an early stage. So first, ROM
DR of the vehicle position display program A stored in
The program is developed on the AM 23, and the vehicle position is displayed prior to another program. The developed vehicle position display program A is generated and started as a task in the processing S17 after the development, and in the processing S20, the azimuth sensor 1 and the distance input through the sensor signal processing unit 4 in FIG. Based on the signal from the sensor 2 and the vehicle position information received by the GPS receiver 5, the current position of the vehicle is continuously displayed together with the map on the liquid crystal display 8A.

On the other hand, while the running position display processing is being performed, if another function is read from the user, for example, an index search function by pressing the touch panel 8B, the index search program B is stored in the DRAM 23 at this stage. In step S19, the index search program B stored in the ROM 22 as shown in FIG.
Is decompressed and expanded on the DRAM 23, and an index search is executed in step S20. If the user calls the same function again after this index search process is completed,
Since the index search program has already been developed on the DRAM 23, the process proceeds from the process S18 to the process S20.

If the area to be developed on the DRAM 23 is insufficient at the stage where the processing S19 is executed by calling some function, the program developed on the DRAM 23 that is not required to be processed is loaded into the development area. Remove from. For example, in the above case, when the index search function is terminated and the user next calls the route search function, the index search program B developed on the DRAM 23 is deleted as shown in FIG. The stored route search program C is decompressed and expanded on the DRAM 23. Thereafter, similarly, when a program not expanded on the expansion area becomes necessary, the compressed part A
-2, the program is expanded on the DRAM 23. If the capacity of the expansion area becomes insufficient at the time of expansion, the unprocessed programs in the expansion area are deleted from the expansion area, and the compressed program is deleted. Continue deployment.

As described above, according to the second embodiment,
When a compressed program is used, necessary programs are decompressed and expanded in the DRAM 23, and unnecessary programs are deleted from the DRAM 23. Therefore, the expanded area of the DRAM 23 can be shared between programs. In addition, the capacity of the development area on the DRAM 23 can be reduced.

[0023]

According to the present invention, as is apparent from the above description, even if the program to be stored exceeds the capacity of the read-only memory or the electrically rewritable memory, the program is compressed. The program is stored in a memory, and after power is turned on, it is decompressed and expanded into a rewritable memory as needed, so that a necessary program can be stored without increasing the memory.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing a configuration of a vehicle-mounted traveling position display device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a data storage structure in an electrically rewritable ROM according to the embodiment of the present invention.

FIG. 3 is a schematic diagram showing a data storage structure from an electrically rewritable ROM to a rewritable DRAM according to the embodiment of the present invention;

FIG. 4 is a flowchart showing a program expansion process according to the first embodiment of the present invention;

FIG. 5 is a flowchart showing a program expansion process according to the second embodiment of the present invention.

FIG. 6 is a schematic diagram showing a program partial expansion process according to the second embodiment of the present invention;

FIG. 7 is a schematic diagram showing a program partial expansion process according to the second embodiment of the present invention (continued)

FIG. 8 is a schematic diagram showing a program partial expansion process according to the second embodiment of the present invention (continued)

FIG. 9 is a schematic block diagram showing a configuration of a vehicle-mounted traveling position display device in a conventional example.

FIG. 10 is a flowchart showing processing after power-on in a conventional apparatus.

[Explanation of symbols]

 Reference Signs List 1 direction sensor 2 distance sensor 3 sensor signal 4 sensor signal processing unit 5 GPS receiver 6 CD-ROM drive 7 CD-ROM 8 display / operation unit 9 main body 13 SRAM 14 kanji / font ROM (read-only memory) 15 image processor 16 VRAM 17 RGB conversion circuit 18 Communication interface 19 Runaway monitoring circuit 20 CPU 21 Compression / decompression unit 22 ROM (electrically rewritable memory) 23 DRAM (memory rewritable at any time)

Claims (5)

[Claims] 1. An electronic control device for controlling operation using a microcomputer having a memory that can be rewritten at any time and a read-only memory or an electrically rewritable memory, wherein the read-only memory or the electrically rewritable memory An electronic control device, comprising: means for storing a compressed program in a suitable memory, decompressing the compressed program when the power is turned on, and expanding the program on the rewritable memory as needed. 2. The electronic control device according to claim 1, wherein both the non-compressed program and the compressed program are arranged in a read-only memory or an electrically rewritable memory. 3. An uncompressed program stored in a read-only memory or an electrically rewritable memory,
3. The electronic control device according to claim 2, wherein a program that requires processing when the power is turned on is arranged. 4. The electronic control device according to claim 2, wherein the decompression processing of the compressed program is performed in parallel during the processing of the non-compressed program to be executed when the power is turned on. 5. When using a compressed program, a required program is decompressed and expanded in a rewritable memory as needed, and an unnecessary program is deleted from the rewritable memory as needed. The electronic control device according to claim 1.