JP2001073864A - Control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a delay in starting the control processing and perform storage and restoration of the data certainly. SOLUTION: An engine control device performs a control processing using a standby RAM (SRAM hereinafter) and a storing processing for copying the specific data in SRAM in an EEPROM, and if the first processing executed at starting the operation passes a judgement that the data in SRAM is in failure (S110: YES), only the initiation is conducted in which the initiation value data is written in the SRAM so that the data is normalized, and the hysteresis data in the SRAM to exhibit data complete/non-complete of the data restoration from the EEPROM to the SRAM is turned into 'non-complete' (S140 and S150). If then the second processing executed in parallel with the control processing passes a judgement that initialization has been conducted (S210 and 220: YES), the specific data in the EEPROM is copied in the SRAM and the data is restored, and the hysteresis data is turned into 'complete' (S240 and S250). In the storing processing, the data in SRAM is copied in the EEPROM (S330) only in the case the hysteresis data is in 'complete' (S320: YES).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular control device for controlling a control object in a vehicle, and more particularly to a specific control data which needs to be permanently updated and stored among data used for control processing. Transfer data to EEPROM or flash RO
The present invention relates to a vehicular control device that is stored in an electrically rewritable nonvolatile rewritable ROM such as M.

[0002]

2. Description of the Related Art Conventionally, as a vehicle control device of this type, for example, as disclosed in Japanese Patent Application Laid-Open Nos. 10-252546, 10-25247 and 4-336351, Japanese Patent Application Laid-Open No. 4-336351. Using a standby RAM (also called a backup RAM) constantly supplied with power from a battery mounted on a vehicle, a control process for controlling a control target in the vehicle is performed, and data in the standby RAM calculated by the control process Of these, specific data that needs to be permanently updated and stored, such as learning values and vehicle cumulative mileage data, are copied to a non-volatile electrically rewritable ROM. Performs a save process, and detects that the data in the standby RAM has become abnormal due to battery disconnection or the like. Case, copy the specific data in the rewritable ROM to the standby RAM, there is that so as to restore the particular data.

In the above-described conventional vehicle control device,
The above-mentioned storage processing (processing of copying specific data in the standby RAM to the rewritable ROM) is performed in parallel with the control processing, and processing that is first executed prior to the control processing after the apparatus starts operation. Then, the quality of the data in the standby RAM is checked by a method such as parity check or mirroring, and when it is determined that the data in the standby RAM is abnormal, the specific data in the rewritable ROM is transferred to the standby RAM. After copying, the control process using the standby RAM is started. Note that mirroring is to store the same data in different areas of the storage medium and determine that the data is normal if the data in each area has the same value.

For this reason, even if the data in the standby RAM is destroyed due to a drop in battery voltage or the battery is disconnected, the specific data (backup data) that has been backed up in the rewritable ROM by the above-described storage processing is stored in the standby RAM. To perform a control process that inherits the process up to that point.

[0005]

However, the above-described conventional vehicle control device has the following problems. First, in this type of device, generally, an EEPROM in which data is read and written through a serial data line is used as a rewritable ROM, but such a rewritable ROM has a RAM and a data rewritable. Reading and writing data takes time compared to a normal ROM (non-rewritable ROM) that cannot be used.

[0006] In the above-mentioned conventional apparatus, the processing executed first after the operation is started prior to the control processing is as follows.
The data in the rewritable ROM is copied to the standby RAM, and thereafter, the control process is started. For this reason, in the above-mentioned conventional device, when the operation is started in a state where the data in the standby RAM is destroyed due to the battery being disconnected or the like, the delay time until the control processing is started becomes longer, and as a result, The time until the controlled object can be operated becomes longer than usual.

[0007] Therefore, the present inventor, if it is determined in the process A, which is executed first before the control process after the operation is started, that the data in the standby RAM is abnormal, for the first time, Write only fixed initial value data that does not hinder the control of the control target from the non-rewritable ROM to the standby RAM, and perform only initialization to normalize the data in the standby RAM. It is determined whether or not the initialization of the standby RAM has been performed by the above-described process A in the process B which is executed in a random manner. If the determination is affirmative, the specific data in the rewritable ROM is copied to the standby RAM. I thought about a program configuration such as

In other words, if the data in the standby RAM is abnormal, the control processing is started by writing the initial value data minimum necessary for the control of the control object into the standby RAM. The original backup data in the ROM is copied to the standby RAM, so that the delay time from the start of the operation to the start of the control processing and the time from the start of the operation of the control target can be reduced. Minimize.

[0009] However, the present inventor has noticed that even if the above configuration is adopted, the following problem still arises.
That is, in order to ensure that the data backed up in the rewritable ROM is copied to the standby RAM and reflected in the control processing, the rewritable RO in the processing B is used.
When the data in M is to be copied to the standby RAM, first, it is determined whether or not the voltage supplied to the standby RAM is a voltage value at which data can be normally written. Only when the determination is affirmative, the data in the rewritable ROM is
It is necessary to take steps such as copying to M.

However, in this type of apparatus, the saving process of copying specific data in the standby RAM to the rewritable ROM is performed in parallel with the control process. If the voltage determination in the process B continues to be negative after the process is performed, the standby process is performed by the storage process before the data copy (copy of the original backup data) from the rewritable ROM to the standby RAM is completed. Data in the RAM may be copied to the rewritable ROM.

When such a situation occurs, the data in the standby RAM, which does not inherit the background, is copied to the rewritable ROM. As a result, the last data for restoring the data is restored. Thus, the original backup data in the rewritable ROM, which is the fortress, is lost.

The present invention has been made in view of such a problem, and can minimize a delay time from the start of an operation to the start of a control process. It is an object of the present invention to provide a vehicle control device capable of reliably performing restoration.

[0013]

SUMMARY OF THE INVENTION In order to achieve the above object, a vehicle control apparatus according to the present invention uses a standby RAM which is always supplied with power from a battery mounted on the vehicle. A nonvolatile rewritable ROM capable of performing a control process for controlling a control target in the RAM and electrically rewriting specific data in the standby RAM calculated by the control process.
Is performed, and if it is determined that the data in the standby RAM is abnormal,
The specific data in the rewritable ROM is stored in a standby RA.
The specific data is restored by copying to the M.

Here, in particular, in the vehicle control device of the present invention, the first processing and the second processing described below are performed, and the storage processing is performed as follows. First, the first process is executed at least before the device starts operating and before starting the control process. In the first process, it is determined whether or not the data in the standby RAM is abnormal. If it is determined that the data is abnormal, a nonvolatile non-rewritable ROM (normal ROM) in which data cannot be rewritten is determined. From the rewritable ROM to the standby RAM, indicating whether or not data copying from the rewritable ROM to the standby RAM has been completed. The history data in the predetermined area is set to contents indicating incomplete.

The second process is periodically executed in parallel with the control process. Then, in the second process, it is determined whether or not the data in the standby RAM is normal and the history data has contents indicating incomplete, and if the determination is affirmative, the standby process is performed by the first process. Judging that the above initialization of the RAM has been performed,
It is determined whether or not the voltage supplied to the standby RAM is a voltage value at which data can be normally written. If the voltage determination is affirmative, the specific data in the rewritable ROM is determined. Is copied to the standby RAM, and the history data is copied to the rewritable RO.
The content is reset to indicate that data copying from M to the standby RAM has been completed.

In the storing process, the standby RAM is used.
RO in which the data in is normal and the history data is rewritable
A determination is made as to whether or not the content is set to indicate that data copying from M to the standby RAM has been completed, and only when the determination is affirmative, the specific data in the standby RAM is copied to the rewritable ROM. I do.

That is, in the vehicle control device of the present invention, at least in the first processing executed prior to the control processing immediately after the start of the operation, if it is determined that the data in the standby RAM is abnormal, For the time being, write only the initial value data necessary for the control of the control target from the normal non-rewritable ROM to the standby RAM, and perform only the initialization for normalizing the data in the standby RAM. Data copy (that is, the specific data in the rewritable ROM is
M is copied to M, that is, restoration of specific data), and the history data in the standby RAM indicating whether or not the data has been completed is set to the content indicating incomplete.

After that, in a second process which is periodically executed in parallel with the control process, when it is determined that the data in the standby RAM is normal and the history data has a content indicating incompleteness, the affirmative determination is made. After determining that the initialization of the standby RAM has been performed by the first processing, and confirming that the voltage supplied to the standby RAM is a voltage value at which data can be normally written. , Specific data in the rewritable ROM is transferred to the standby RA.
M, and the history data in the standby RAM is reset to a content indicating that the data copy from the rewritable ROM to the standby RAM is completed.

Therefore, according to the vehicular control apparatus of the present invention, when the data in the standby RAM is abnormal, the control processing is started by writing the initial value data in the non-rewritable ROM to the standby RAM for the time being. Then, the original backup data in the rewritable ROM is copied to the standby RAM. Therefore, even when the operation is started in a state in which the data in the standby RAM is destroyed due to a missing battery or the like, the delay time before the control processing is started is not long, and the time until the control target is activated is minimized. Can be

Further, in the vehicle control device of the present invention, when the data in the standby RAM is determined to be abnormal in the first processing and the initialization is performed, the history data in the standby RAM is not completed. In the second processing, the specific data in the rewritable ROM is set to the standby RA.
When copying to M (when data restoration is completed)
Reset the history data to the content indicating completion, and further,
In the saving process, specific data in the standby RAM is copied to the rewritable ROM only when the data in the standby RAM is normal and the history data is set to a content indicating completion.

For this reason, if the initialization of the standby RAM is performed in the first processing, a negative determination is made in the voltage determination in the second processing, and the data copy from the rewritable ROM to the standby RAM is completed. Even if a situation where the data is not written is generated, it is possible to reliably prevent the data in the standby RAM from being copied to the rewritable ROM by the saving process in the situation.

In other words, if the data in the standby RAM becomes abnormal due to the battery being disconnected, etc., "initialization of the standby RAM by the first processing" → "rewriting from the rewritable ROM to the standby RAM by the second processing" The data transfer order of "data copy" → "data copy from standby RAM to rewritable ROM by storage processing" is reliably maintained, and loss of the original backup data in rewritable ROM is reliably prevented. Because

Therefore, according to the vehicle control apparatus of the present invention, all the problems described in “Problems to be Solved by the Invention” are solved, and the delay from the start of the operation to the start of the control processing is solved. The time can be minimized, and the data used in the control processing can be reliably saved and restored.

Further, according to the vehicle control device of the present invention, since the history data is stored in the standby RAM, for example, after the initialization is performed in the first process, the second data is stored in the standby RAM. From the rewritable ROM to standby R
Even if the operating voltage to the device is cut off before the data is copied to the AM, the rewriting is performed by the second process when the operating voltage is supplied next time and the device starts operating. The data copy from the possible ROM to the standby RAM can be reliably performed, and the data may be copied from the standby RAM to the rewritable ROM by the storage process until the data copy by the second process is completed. There is no.

Therefore, even if the operating voltage to the device is interrupted, the data transfer order can always be reliably maintained, and data can be saved and restored reliably.
In the vehicle control device of the present invention, the data in the standby RAM is normal at normal times, and the history data in the standby RAM is set to the content indicating completion. No initialization is performed, and in the second process, data is not copied from the rewritable ROM to the standby RAM. Then, by the storage processing performed in parallel with the control processing, specific data in the standby RAM is copied to the rewritable ROM, so that the data in the standby RAM is destroyed.

According to a second aspect of the present invention, in the vehicle control apparatus according to the first aspect, in the control processing, the copying of the history data from the rewritable ROM to the standby RAM is completed. The specific data in the standby RAM is updated only when the content is set to indicate that the operation has been performed.

That is, when the history data is not set to the content indicating the completion, the original data inheriting the process up to that time has not yet been copied from the rewritable ROM to the standby RAM. Standby R
This is because there is no point in updating specific data in the AM by control processing. According to the vehicle control device of the second aspect, the control process can be efficiently advanced, which is advantageous.

[0028]

Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 1 is a block diagram illustrating a configuration of a vehicle control device (hereinafter, referred to as an ECU) 1 of an embodiment that controls an engine mounted on a vehicle.

As shown in FIG. 1, the ECU 1 of this embodiment
Executes various processes for controlling the engine.
PU3, ROM storing a program executed by CPU3 and data referred to when the program is executed
5, a microcomputer (hereinafter, referred to as a microcomputer) 11 including a RAM 6 for storing a calculation result by the CPU 3, a standby RAM (hereinafter, referred to as an S-RAM) 7, an input / output interface (I / O) 9, and the like; Nonvolatile rewritable RO that can rewrite data
And an EEPROM 13 as M. And
The microcomputer 11 and the EEPROM 13 are connected via a serial data line 15 so that data can be transferred.

Note that, of the RAM 6 and the S-RAM 7,
-Power is always supplied to the RAM 7 from the battery 27 mounted on the vehicle. The ROM 5 is a nonvolatile read-only memory in which data cannot be rewritten. Further, the ECU 1 causes the microcomputer 11 to input signals from various sensors such as a vehicle speed sensor 17 for detecting a traveling speed (vehicle speed) of the vehicle and a rotation sensor 19 for detecting the number of revolutions of the engine. The microcomputer 1 receives an input / output circuit 25 for driving actuators such as the injector 21 and the igniter 23 and an ignition voltage VIG supplied from a battery 27 via an ignition switch 29 of the vehicle in response to the output control signal.
1, a main power supply circuit 31 for supplying the operating voltage VD to the EEPROM 13 and the like, and a battery voltage VBB directly supplied from the battery 27 without passing through the ignition switch 29.
And a sub-power supply circuit 33 for supplying a standby voltage VS for holding data to the S-RAM 7 in the microcomputer 11 upon receipt of the signal.

In such an ECU 1, when the ignition switch 29 is turned on, the main power supply circuit 3
1 to the microcomputer 11, the EEPROM 13, etc.
D is supplied. Then, the CPU 3 of the microcomputer 11
A control process for controlling the engine is executed in accordance with a program stored in the ROM 5, and the actuator is operated based on sensor signals from various sensors to control the engine.

Here, the CPU 3 of the microcomputer 11 executes S-
The control process is performed using the RAM 7, and among the various control data in the S-RAM 7 calculated by the control process,
Specific data that needs to be permanently updated and stored (hereinafter, referred to as storage target data), such as learning value data for control and accumulated mileage data of the vehicle, is referred to as EE.
The data is also copied and stored in the PROM 13.
When it is determined that the data in the S-RAM 7 is abnormal, the storage target data in the
-By copying the data to the RAM 7, even if the data in the S-RAM 7 is destroyed due to the battery 27 being removed from the vehicle or the like, the data to be saved is not lost. The ROM 5 stores in advance initial values (corresponding to fixed initial value data) of various control data including the storage target data.

Next, the processing executed by the microcomputer 11 of the ECU 1 will be described with reference to the flowcharts of FIGS. First, C of the microcomputer 11
When the operation starts (initial start) when the ignition switch 29 is turned on, the PU 3 executes the first processing shown in FIG. 2A before starting the control processing.
In the present embodiment, the first process is not only executed at the time of the initial state (that is, at the time of starting the operation of the ECU 1), but thereafter, is repeated at regular intervals (every 65 ms in the present embodiment). Be executed.

Then, as shown in FIG. 2A, when the execution of the first process is started, first, in step (hereinafter referred to as "S") 110, the data in the S-RAM 7 is abnormal. It is checked whether or not the data in the S-RAM 7 is abnormal (that is, normal) by a method such as parity check or mirroring.
The first process is terminated as it is, and the control process using the S-RAM 7 is started.

On the other hand, in S110, S-RA
If it is determined that the data in M7 is abnormal, S1
Proceeding to 20, the S-RAM 7 indicates the data state in the S-RAM 7.
The RAM state variable is set to a content indicating “abnormal”.
The S-RAM state variable is data stored in a predetermined area of the RAM 6, and its initial value is
"Normal" by initial processing (not shown) for
Is set to

Next, at S130, the sub power supply circuit 3
3 to the standby voltage V supplied to the S-RAM 7
It is determined whether or not S is a normal voltage value at which data writing to the S-RAM 7 can be normally performed. If S is a normal voltage value, it is determined that the writing to the S-RAM 7 is not in a prohibited state. Then, the process proceeds to S140.

Then, in S140, initialization for writing various control data initial values (initial value data) from the ROM 5 to the S-RAM 7 to normalize the data in the S-RAM 7 is performed, and then in S150. , EEPROM 13
The history data DR indicating whether or not the copying of the data to be saved from the to the S-RAM 7 has been completed is set to the content indicating “incomplete”. Note that this history data DR is SR-R
This is data stored in a predetermined area of AM7.

Further, at S160, the S-
Reset the RAM status variable to indicate "normal",
After that, the first process ends. In addition, S13
At 0, if it is determined that the write to the S-RAM 7 is prohibited (that is, if it is determined that the standby voltage VS is not a normal voltage value), the first process is temporarily terminated. Then, in this case, when the first process is next executed, it is again determined in S110 that the data in the S-RAM 7 is abnormal, and the processes after S120 are performed again. .

Next, the CPU 3 of the microcomputer 11 starts executing the control processing after performing the first processing at the time of initializing. In parallel with the control processing, the CPU 3 in FIG.
The second process shown in FIG. 2B and the storage process shown in FIG. 2C are repeatedly executed at regular intervals (in this embodiment, every 16 ms). The saving process is a process for copying the data to be saved in the S-RAM 7 to the EEPROM 13 and saving the data. The substantial saving process is performed only when a later-described saving condition is satisfied. Will be

First, as shown in FIG.
Starts the execution of the second process, at first S210, it is determined whether or not the data in the S-RAM 7 is normal by referring to the S-RAM state variable in the RAM 6. If the S-RAM state variable is set to a content indicating "normal", it is determined that the data in the S-RAM 7 is normal, and the process proceeds to S220.
It is determined whether or not the history data DR in the AM 7 is set to a content indicating “incomplete”.

If it is determined in step S220 that the history data DR is set to indicate "incomplete",
It is determined that the S-RAM 7 has been initialized by the first process described above, and the process proceeds to S230. In S230, as in S130 in the first process, the standby voltage V
It is determined whether or not S is a normal voltage value at which data writing to the S-RAM 7 can be normally performed. If S is a normal voltage value, it is determined that the writing to the S-RAM 7 is not in a prohibited state. Then, the process proceeds to S240. And in this S240,
The data to be stored in the EEPROM 13 is copied to the S-RAM 7, and in S250, the history data DR in the S-RAM 7 is replaced with a content indicating "completion" (ie, EEPROM
(Indicating that the data copy from the OM 13 to the S-RAM 7 has been completed). Then, thereafter, the second process ends.

If it is determined in S210 that the data in the S-RAM 7 is not normal (that is,
When the state variable is set to the content indicating “abnormal”), or when it is determined in S220 that the history data DR is not set to the content indicating “incomplete”, or in S230 , When it is determined that the writing to the S-RAM 7 is prohibited (that is, the standby voltage VS
Is not a normal voltage value), the second process is temporarily terminated.

Next, as shown in FIG.
Starts the execution of the saving process, first, in S305, it is determined whether or not the saving condition is satisfied. This storage condition is a condition provided to reduce the number of times of writing data to the EEPROM 13. In the present embodiment, for example, when both of the following conditions are satisfied, it is determined that the storage condition is satisfied. judge.

During the period in which the ECU 1 is continuously operating, there was an operation state in which the vehicle speed was 20 km / h or more and the engine speed was 2000 rpm or more. : During the period when the ECU 1 is continuously operating, the data to be stored in the S-RAM 7 has not been copied to the EEPROM 13 even once by the processing of S 330 described later.

That is, in this embodiment, if the above condition is satisfied during the period when the ECU 1 is continuously operating, the data to be saved in the S-RAM 7 is stored in the S-RAM 7 only once.
The data is copied to the PROM 13 so that the number of times of writing data to the EEPROM 13 is minimized.

If it is determined in S305 that the storage condition is not satisfied, the storage process is terminated. If the storage condition is satisfied, the process proceeds to S3.
Proceeding to 10, it is determined whether or not the data in the S-RAM 7 is normal by referring to the S-RAM state variable in the RAM 6.

Here, if the S-RAM state variable is set to a content indicating "normal", it is determined that the data in the S-RAM 7 is normal, and the process proceeds to S320.
It is determined whether or not the history data DR in the RAM 7 is set to a content indicating “completed”.

If it is determined in step S320 that the history data DR is set to indicate "complete", the flow advances to step S330 to copy the data to be stored in the S-RAM 7 to the EEPROM 13, and thereafter, Then, the storage process ends. When it is determined in S310 that the data in the S-RAM 7 is not normal (that is, when the
If the M state variable is set to the content indicating “abnormal”), or if it is determined in S320 that the history data DR is not set to the content indicating “complete”, the storage is performed as it is. The process ends.

A main relay controlled by the microcomputer 11 is provided between the plus terminal of the battery 27 and the main power supply circuit 31. The microcomputer 11 turns on the main relay even after the ignition switch 29 is turned off. If you are configured to continue operation,
As the above-mentioned storage condition, a condition that the ignition switch 29 is turned off from the on state may be added. That is, in this case, normally, the ignition switch 29 is turned off from the on state, and the ECU 1
The data to be stored in the S-RAM 7 is copied to the EEPROM 13 only once before the operation stops.

On the other hand, the CPU 3 of the microcomputer 11 sequentially updates the storage target data in the S-RAM 7 to the latest contents by the control processing.
With reference to the history data DR in the AM 7, the storage target data in the S-RAM 7 is updated only when the history data DR is set to a content indicating "complete".

For example, FIG. 3 is a flowchart showing a mileage calculating process executed at regular time intervals T to accumulate and calculate the mileage of the vehicle in the control process. In S410, the travel distance Δ within the fixed time T is calculated from the vehicle speed at that time, and in S420, it is determined whether or not the history data DR in the S-RAM 7 is set to indicate “completed”. I do. And
Only when the history data DR is set to the content indicating “completed”, the process proceeds to the next S430, where the traveling distance Δ calculated in S410 is added to the accumulated traveling distance data in the S-RAM 7, and Update the accumulated mileage data.

As described above, the ECU 1 of this embodiment determines whether or not the data in the S-RAM 7 is abnormal at least in the first processing executed immediately before the start of the operation and prior to the control processing. Then (S110), when it is determined that there is an abnormality (S110: YES), the normal RO
Only the initialization for writing the initial values of various control data from M5 to the S-RAM 7 to normalize the data in the S-RAM 7 is performed (S140), and the copy of the data to be saved from the EEPROM 13 to the S-RAM 7 is performed. The history data DR in the S-RAM 7 indicating whether or not the process has been completed is
The content indicating “incomplete” is set (S1
50).

Then, in a second process which is periodically executed in parallel with the control process, the data in the S-RAM 7 is normal and the history data DR has a content indicating "incomplete". (S210 and S220:
YES), it is determined that the initialization of the S-RAM 7 has been performed by the first processing, and after confirming that the standby voltage VS supplied to the S-RAM 7 is a normal voltage value (S230: NO) ), And copy the data to be stored in the EEPROM 13 to the S-RAM 7 (S2).
40), the history data DR in the S-RAM 7 is reset to the content indicating "complete" (S25).
0).

Therefore, according to the ECU 1 of this embodiment, if the data in the S-RAM 7 is abnormal,
For the time being, fixed initial value data is written into the S-RAM 7 to start the control processing.
Is copied to the S-RAM 7. Therefore, S-
Even when the operation is started in a state where the data in the RAM 7 has been destroyed, the delay time before the control processing is started is not long, and the time until the controlled object is activated can be minimized.

Further, in the ECU 1 of the present embodiment, the first
In the process (1), when the data in the S-RAM 7 is determined to be abnormal and the initialization is performed, the history data DR in the S-RAM 7 is set to a content indicating "incomplete" (S150). In the processing of step 2, the data to be stored in the EEPROM is
When the data is copied to the RAM 7 (when the data restoration is completed), the history data DR is reset to the content indicating “completed” (S250). Only when the data in the file is normal and the history data DR is set to the content indicating “completed” (S310 and S320: YES), the S-RAM
7 is copied to the EEPROM 13 (S330).

Therefore, suppose that S1 in the first processing is
After the initialization of the S-RAM 7 is performed in 40, it is determined that the standby voltage VS is not a normal voltage value in the voltage determination in S230 in the second process (negative determination is made in the write-protected state). , EEPROM 13 to S-RAM
Even if a situation occurs in which the data copy to the S-RAM 7 has not been completed, the S-RAM 7
Copying of data in the EEPROM 13 to the EEPROM 13 is reliably prevented.

That is, when the battery is disconnected, the S-RA
If the data in M7 becomes abnormal, “initialization of S-RAM 7 by first processing” → “E-RAM by second processing”
Data Copy from EPROM 13 to S-RAM 7 "→
The data transfer order of "copying data from the S-RAM 7 to the EEPROM 13 by the preservation process" is reliably maintained, and loss of the original backup data in the EEPROM 13 is reliably prevented.

Therefore, according to the ECU 1 of the present embodiment,
The delay time from the start of the operation to the start of the control processing can be minimized, and the data used in the control processing can be reliably stored and restored. Further, according to the ECU 1 of the present embodiment, since the history data DR is stored in the S-RAM 7, if the initialization of the S-RAM 7 is performed in the first process, the second
In S240 in the process of S-R from the EEPROM 13
By the time the data is copied to the AM 7, the ignition switch 29 is turned off and the main power supply circuit 31 is turned off.
Even if the operating voltage VD is interrupted, when the operating voltage VD is supplied the next time and the ECU 1 starts operating, the S-RA
The data copy to the M7 can be reliably performed, and the data is not copied from the S-RAM 7 to the EEPROM 13 by the storage process until the data copy from the EEPROM 13 to the S-RAM 7 is completed. Therefore, even if the operating voltage VD is intermittent, the data transfer order can always be reliably maintained, and data can be saved and restored reliably.

In the ECU 1 of this embodiment, in the control processing, the history data DR in the S-RAM 7 is referred to, and the history data DR is read from the EEPROM 13 by the S
-The storage target data in the S-RAM 7 is updated only when the content indicating that the data copy to the RAM 7 is completed is set. Therefore, the control process can proceed efficiently. That is, the history data D
If R is set to indicate "incomplete",
Since the original data to be saved, which inherits the process up to that point, has not yet been copied from the EEPROM 13 to the S-RAM 7, it is meaningless to update the data to be saved in the S-RAM 7 at that time by control processing. It is.

In the ECU 1 of this embodiment, the data in the S-RAM 7 is normal at normal times,
Since the history data DR in the S-RAM 7 is set to indicate “completed”, the first process uses the S-RAM
7 is not initialized, and in the second process, the EEPR
Data copy from the OM 13 to the S-RAM 7 is not performed. The data to be stored in the S-RAM 7 is stored in the EEPROM 1 by the storage processing performed in parallel with the control processing.
3 and the data in the S-RAM 7 is destroyed.

The embodiment of the present invention has been described above, but it goes without saying that the present invention can take various forms. For example, in the above embodiment, S2 of the second processing
10 and S310 of the storage process,
S-RAM7 by referring to RAM state variables
It is determined whether or not the data inside is normal. In S210 and S310, similar to S110,
Whether the data in the S-RAM 7 is normal may be checked by a method such as parity check or mirroring.

Further, in the above-described embodiment, the second processing and the storage processing are separately performed as shown in FIG. 2, but the second processing in FIG. Even if the storage process of C) is performed, exactly the same effect can be obtained. On the other hand, the ECU 1 of the above-described embodiment controls the engine of the vehicle. However, a device that controls another control target, such as an automatic transmission, may be configured in exactly the same manner.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a vehicle control device (ECU) according to an embodiment.

FIG. 2 is a flowchart illustrating a first process, a second process, and a storage process executed by a microcomputer of the ECU according to the embodiment.

FIG. 3 is a flowchart illustrating a part of a control process executed by a microcomputer of an ECU according to the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... ECU (Vehicle control device) 3 ... CPU 5 ...
ROM 7: S-RAM (standby RAM) 11: microcomputer 13: EEPROM 15: serial data line
Reference Signs List 17 vehicle speed sensor 19 rotation sensor 21 injector 23 igniter 25 input / output circuit 27 battery 29 ignition switch 31 main power supply circuit 33 sub power supply circuit

Claims (2)

[Claims] A control process for controlling a control target in the vehicle is performed by using a standby RAM constantly supplied with power from a battery mounted on the vehicle, and the standby RAM calculated by the control process is controlled by the control process. Performing a save process of copying and storing the specific data in a nonvolatile rewritable ROM in which data can be electrically rewritten, and further, when it is determined that the data in the standby RAM is abnormal, By copying the specific data in the rewritable ROM to the standby RAM,
In the vehicle control device configured to restore the specific data, at least a process that is executed before the device starts operating and starts the control process, wherein the standby R
It is determined whether or not the data in the AM is abnormal. If it is determined that the data is abnormal, the initial value data is written from the nonvolatile non-rewritable ROM in which data cannot be rewritten to the standby RAM, and Initialization for normalizing the data of the standby RAM is further performed, and the history data in a predetermined area of the standby RAM, which indicates whether data copying from the rewritable ROM to the standby RAM has been completed, is indicated as incomplete. A first process for setting the content, and a process periodically executed in parallel with the control process, wherein the data in the standby RAM is normal and the history data is content indicating incomplete. Judge whether or not
If the determination is affirmative, the standby R
It is determined whether or not the voltage supplied to the AM is a voltage value at which data can be normally written. If the voltage determination is affirmative, the rewritable ROM is used.
And copying the specific data in the standby RAM to the standby RAM, and resetting the history data to contents indicating that the data copy from the rewritable ROM to the standby RAM is completed. Further, in the storing process, the data in the standby RAM is normal and the history data is stored in the rewritable ROM.
It is determined whether or not the content is set to indicate that the data copy to the standby RAM has been completed. Only when the determination is affirmative, the standby RA
M. The specific data in M is copied to the rewritable ROM. 2. The vehicle control device according to claim 1, wherein in the control processing, the history data is the rewritable RO.
A control device for a vehicle, characterized in that the specific data in the standby RAM is updated only when the content indicating that data copying from the M to the standby RAM is completed is set.