JP2830302B2 - Automotive control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile control device.

[Conventional technology]

2. Description of the Related Art Conventionally, in an automobile, an amount of fuel supplied to an engine is adjusted by an electronic control unit. A ROM (read only memory) is externally attached to the processing device, and various data are stored in the ROM.

[Problems to be solved by the invention]

When writing data to a nonvolatile memory such as a ROM built in a microcomputer, the data can only be written by a program.

However, in the case of an external non-volatile memory, the non-volatile memory can be removed from the board and written with a ROM writer, or can be written by applying a probe to a predetermined terminal while the non-volatile memory is mounted on the board.

Therefore, even after shipment from an automobile manufacturer or after changing data at a dealer, the user rewrites the contents of the external non-volatile memory (program, fuel amount supplied to the engine, fuel cut speed, etc.). Thus, the control state of the vehicle may be changed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a control device for a vehicle, which can avoid a problem associated with data tampering of an external nonvolatile memory.

[Means for solving the problem]

A microcomputer having a rewritable first non-volatile memory and a memory storing a program for writing data to the first non-volatile memory, and data for controlling the control target by the microcomputer. And a rewritable second non-volatile memory provided outside the microcomputer, in which the check data based on the data stored in the second non-volatile memory is stored in the first non-volatile memory. Check data writing means for writing to the first nonvolatile memory by a program for writing data to the memory; and check data calculating means for calculating check data based on the data stored in the second nonvolatile memory during normal control. Comparing the calculated check data with the check data stored in the first nonvolatile memory, The automobile control system, characterized in that it comprises a data abnormality detecting means for detecting an atmospheric it is an gist.

The invention according to claim 2, wherein the check data writing means converts the check data based on the data stored in the second nonvolatile memory into the first nonvolatile memory only once based on a program for writing the data into the first nonvolatile memory. The gist is that the data is written into the nonvolatile memory.

[Action]

According to the configuration of the first aspect, the check data writing means writes the check data based on the data stored in the second nonvolatile memory to the first nonvolatile memory by the program stored in the memory.

During normal control, the check data calculation means calculates check data based on the data stored in the second nonvolatile memory.

The data abnormality detection means compares the calculated check data with the check data stored in the first non-volatile memory to detect data abnormality.

According to the configuration of the second aspect, the check data writing unit converts the check data based on the data stored in the second nonvolatile memory only once based on a program for writing the data into the first nonvolatile memory. Write to the first nonvolatile memory.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the electrical configuration of the vehicle control device of this embodiment.

The microcomputer 1 as a processing device of the engine control system includes a central processing unit (hereinafter referred to as a CP) as a check data calculating unit, a data abnormality detecting unit, and a check data writing unit.
U) 2, a random access memory (hereinafter referred to as RAM) 3, and an E ² PROM 4 as a first nonvolatile memory. The CPU ² , the RAM 3, and the E ² PROM 4 are formed on one chip. A battery 6 is connected to the microcomputer 1 via an ignition switch 5. Further, an external EPROM 7 as a second nonvolatile memory is connected to the microcomputer 1, and the external EPROM 7 stores the amount of fuel supplied to the engine and the number of revolutions of fuel cut.

The CPU 2 of the microcomputer 1 receives an engine speed signal, an engine cooling water temperature signal, and the like. A warning light 8 is connected to the CPU 2, and the warning light 8 is turned on when data in the external EPROM 7 is falsified. Further, an injector as an in-vehicle device is connected to the CPU 2 of the microcomputer 1 via the changeover switch 9.
10 would be connected. The CPU 2 of the microcomputer 1 drives the injector 10 based on the engine speed signal, the engine coolant temperature signal and the like to supply a predetermined amount of fuel to the engine.

A backup IC 11 is connected to the CPU 2 of the microcomputer 1 so that the backup IC 11 controls the changeover switch 9 in response to the input of an abnormal signal from the CPU 2 and controls the injector 10 based on the engine speed signal. Has become. Also, the CPU 2 has a check program storage area for checking whether the data in the external EPROM 7 has been tampered with.
2a is prepared, and data in this area 2a cannot be falsified by some users. The check program storage area 2a forms a memory for storing a program for writing data in the first nonvolatile memory of the present invention.

Next, the operation of the thus configured vehicle control device will be described with reference to the flowchart of FIG.

When the ignition switch 5 is turned on and the power is turned on during vehicle inspection at an automobile manufacturing plant, the CPU 2 starts the processing of FIG.

First, the CPU 2 calculates the total value of the data bits of the external EPROM 7 in step 100, and determines in step 101 whether or not the power is initially turned on (the operation of turning on the ignition switch 5). That is, at the time of inspection at the time of shipment at an automobile manufacturing factory, it is detected that the power has been turned on, and the total value of the data bits of the external EPROM 7 is written to the E ² PROM 4.

Then, the CPU 2 performs fuel control in step 103 for engine inspection at the time of shipment at an automobile manufacturing factory.

Also, after shipping the car from the car manufacturing plant,
When the ignition switch 5 is turned on, the CPU 2 calculates the sum of the data bits of the external EPROM 7 in step 100, and determines in step 101 that the power is not turned on for the first time.
Then, in step 104, the CPU ² compares the total value of the data bits of the external EPROM 7 with the total value of the data bits of the external EPROM 7 stored in the E ² PROM 4, and if they match, the data of the external EPROM 7 is not falsified. Assuming normal, step 103
Performs fuel control by the injector 10.

On the other hand, the CPU 2 determines in step 104 the total value of the data bits of the external EPROM 7 and the external EPROM stored in the E ² PROM 4.
If the sum of the 7 data bits does not match, step 1
At 05, the warning lamp 8 is turned on assuming that the data in the external EPROM 7 has been tampered with. Furthermore, CPU2 is a backup IC11
An abnormal signal is output to In response to this abnormality signal, the backup IC 11 drives the changeover switch 9 to connect the changeover backup IC 11 and the injector 10 as shown by a dashed line in FIG. Thereafter, the backup IC 11 drives and controls the injector 10 based on the engine speed signal to adjust the fuel amount.

As described above, according to the present embodiment, at the time of shipment from an automobile manufacturing plant, the external EPRO
M7 data bits of the sum value of (second nonvolatile memory) E ² PROM 4 storing (check data) in advance (first nonvolatile memory) provided, after shipment from an automobile manufacturing plant,
The microcomputer 1 calculates the total value of the data bits of the external EPROM 7 every time the power is turned on, and compares the total value with the total value of the data bits of the external EPROM 7 stored in the E ² PROM 4. 8 is turned on, and the changeover switch 9 is switched so that the backup IC 11
To adjust the fuel amount of the engine.

As a result, the user can store the contents of the external EPROM 7, for example,
Even if an attempt is made to change the control state of the vehicle by rewriting the amount of fuel supplied to the engine, the number of revolutions of the fuel cut, etc., tampering is found by the check processing in step 104, and the engine is controlled by the backup IC 11. In this manner, even if the data in the external ROM (external EPROM 7) is falsified, the engine control based on the data is not performed.

Note that the present invention is not limited to the above-described embodiment. For example, as data for falsification check,
The sum of the specific bits of the data bits of the external EPROM 7 or the sum of the data bits of the external EPROM 7 multiplied by the key code may be used.

〔The invention's effect〕

As described above in detail, according to the present invention, the check data based on the data stored in the second nonvolatile memory by the check data writing means is written to the first nonvolatile memory by the program for writing the data to the first nonvolatile memory. Since the data is written, if the data in the external nonvolatile memory is tampered with thereafter, the problem can be avoided.

The check data writing means writes the check data based on the data stored in the second nonvolatile memory to the first nonvolatile memory only once based on a program for writing data to the first nonvolatile memory. Then, if the data in the external nonvolatile memory is tampered with thereafter, it is possible to reliably avoid the problem.

[Brief description of the drawings]

FIG. 1 is a diagram showing an electrical configuration of a vehicle control device according to an embodiment, and FIG. 2 is a flowchart for explaining the operation. 1 is a microcomputer as a processing device, 2 is a CPU as check data calculation means, data abnormality detection means, and check data writing means, 4 is an E as a first nonvolatile memory.
² PROM, 7 is an external EPROM as the second nonvolatile memory, 10
Is an injector as an in-vehicle device.

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masao Ito 1-1-1, Showa-cho, Kariya-shi, Aichi Japan Inside Denso Co., Ltd. (56) References JP 1-2222356 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) G06F 12/14 G06F 12/16 F02D 45/00 376

Claims (2)

(57) [Claims] 1. A rewritable first nonvolatile memory and a first rewritable nonvolatile memory.
A microcomputer having a memory for storing a program for writing data to the nonvolatile memory; and a rewritable second memory provided outside the microcomputer for storing data for controlling the control target by the microcomputer.
A controller for writing check data based on data stored in the second nonvolatile memory to the first nonvolatile memory by a program for writing data to the first nonvolatile memory. Data writing means, check data calculation means for calculating check data based on data stored in the second nonvolatile memory during normal control, and check data stored in the first nonvolatile memory and the calculated check data. And a data abnormality detecting means for comparing the data with the data to detect a data abnormality. 2. The method according to claim 1, wherein the check data writing means converts the check data based on the data stored in the second nonvolatile memory into the first nonvolatile memory only once based on a program for writing the data into the first nonvolatile memory. The vehicle control device according to claim 12, wherein the control device writes the data in a memory.