JPH07239777A - Electronic controller with one-chip microcomputer, and its control data storing method - Google Patents

Abstract

PURPOSE:To prevent the productivity from deteriorating and data from being misset without spoiling the flexibility of one-chip microcomputer by providing a mask ROM with a storage area wherein 1st control data transferred to a 1st storage area of an EEPROM are previously registered. CONSTITUTION:A ROM 12 is formed as a mask ROM, and common data which are set in its common data area are automatically transferred to the EEPROM 14 at the time of the 1st execution of an initialization routine. The EEPROM 14 is a rewritable nonvolatile memory, and its common data area is an area wherein the common data automatically transferred from the ROM 12 or common data 6 transferred to a microcomputer 10 through an external device 5 at need are stored. Further, a machine-kind distinctive data area is an area where machine-kind distinctive data 7 transferred to the microcomputer 10 through the external device 5 at the time of shipping are stored.

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 electronically controlling the fuel injection amount and ignition timing of an engine and a control data storing method for the unit, for example, in an automobile, and more particularly to the electronic control unit. The present invention relates to a configuration suitable for application to a device including a one-chip microcomputer as well as an implementation of a control data storage method thereof.

[0002]

2. Description of the Related Art In recent years, most of electronic control devices used for engine control of automobiles include one-chip microcomputers, that is, CPUs, ROMs and RAs.
A microcomputer in which M, an input / output control unit, etc. are integrated in one IC (LSI) chip is used.

By the way, in such a one-chip microcomputer, as its internal ROM,
A so-called mask RO in which programs and data are fixedly written by a mask used in an IC (LSI) manufacturing process.
M is used. Therefore, although the mass productivity and the economical efficiency of the one-chip microcomputer are improved, it is impossible to change the programs and data described (stored) therein, and the versatility of the microcomputer is adversely affected. It is supposed to be done.

Therefore, in recent years, EEPROM (Electrical), which is a non-volatile memory that is electrically rewritable
ly Erasable and Programmable ROM: Electrical
Erasable and programmable ROM) IC
One-chip microcomputers that are also mounted on the chip have been developed.

By mounting such an EEPROM, for example: -By writing various data required for the engine control or the like into the EEPROM, one microcomputer can be shared by many models. become.・ Even if there is a small specification change, it will be possible to quickly respond to this. And so on, the versatility as a one-chip microcomputer can be greatly improved.

[0006]

By the way, in recent years, the memory capacity of the above-mentioned one-chip microcomputer, the operation speed, etc. have been remarkably improved, and accordingly, the control program is provided with more functions and is more complicated. It is becoming a thing. For this reason, the above EEPRO
The number of control data to be written and stored in M is inevitably increasing.

Therefore, although the versatility of the one-chip microcomputer has been improved by mounting the above-mentioned EEPROM, on the contrary, this time: It takes a long time to write the control data in the same EEPROM. However, the writing time deteriorates productivity. -There is also a high possibility that the control data to be written in the EEPROM will be set by mistake. And so on, the problem of will come to the surface.

However, in order to reduce the number of control data to be written in this EEPROM, it is necessary to change the control data (A) that can be commonly used for each model (B) for each model. It is classified into two types of data, and the data that does not need to be changed in (A) is set in advance in the mask ROM.
Such a method is not inconceivable.

However, such control data is usually required to be changed unexpectedly at the development stage when trying to standardize the electronic control device in the future. Therefore, it is dangerous to easily set the control data in the mask ROM, which may be commonly used for each model, regardless of the classification of the control data. When it becomes necessary, it cannot be dealt with. Eventually, the control data setting in the mask ROM hinders the versatility of the one-chip microcomputer, and the stock microcomputer chip itself is wasted.

Incidentally, not only the above-mentioned electronic control device used for controlling the engine of an automobile, but also an electronic control device including a one-chip microcomputer for controlling a plurality of different types of equipment, such a situation is generally present. It is common.

The present invention has been made in view of these circumstances, and does not impair the versatility as a one-chip microcomputer, and further, the productivity is deteriorated and the data setting is deteriorated with the increase in the number of data to be written in the EEPROM. An electronic control device capable of satisfactorily preventing errors and the like,
And a control data storage method thereof.

[0012]

In order to achieve these objects, an electronic control unit including a one-chip microcomputer according to the present invention includes a rewritable nonvolatile memory (EEPROM), and the EEPROM includes:
The mask ROM is provided with a first storage area for storing first control data that can be commonly used for each model and a second storage area for storing second control data different for each model. Is provided with a storage area in which the first control data transferred to the first storage area of the EEPROM is preregistered.

Further, in the control data storing method of the electronic control device including the one-chip microcomputer according to the present invention, the control data of each device can be commonly used for each model and the first control data and the model. The second control data is classified into the second control data which is different for each, and the storage area of the rewritable nonvolatile memory (EEPROM) is divided into the first area in which the first control data is stored and the second control data. The second area to be stored is divided into the first area and the first area.
The control data stored in the mask ROM is transferred to the first area of the EEPROM, and the second control data and the first control data that need to be changed are separately prepared as needed. E through the external device of
The data is transferred to the corresponding area of the EPROM.

In the electronic control device and the control data storage method thereof, the rewritable non-volatile memory (EEPROM) may be built in a one-chip microcomputer together with a CPU, a mask ROM and the like. Alternatively, it may be separately provided outside the microcomputer.

[0015]

According to the above configuration as an electronic control device including a one-chip microcomputer or the above control data storage method, at least the first control data is stored in the mask ROM at the mask stage. Then, for example, when the microcomputer is first turned on and the initialization procedure is executed, the first control data in the mask ROM is automatically written in the EEPROM, and then, for example, at the shipping stage, the second control data is written. The control data, which is different for each model, is externally written in the EEPROM.

Therefore, as for at least the first control data described above, it takes a long time to write the control data in the EEPROM, which deteriorates the productivity. -There is a high possibility that the control data to be written in the EEPROM will be set incorrectly. Problems such as the above will be resolved by themselves.

Further, since the writing of the first control data is simplified and its accuracy is guaranteed, the burden of writing the second control data, which is the remaining control data, in the EEPROM is also large. Will be reduced to. Therefore, there is almost no concern that the above-mentioned problem will be brought to the surface regarding the second control data.

In this one-chip microcomputer, when executing various control programs, the above E
The control data stored in the first and second areas (storage areas) of the EPROM is used.

On the other hand, the first control data, which can be commonly used for each model, may have a change request in the future due to a specification change or the like depending on the model. In such a case, the first area (storage area) of the EEPROM
This is dealt with by externally updating the first control data stored in, for example, at the shipping stage.

Therefore, the versatility of the one-chip microcomputer is not impaired. In view of the fact that the EEPROM itself is a non-volatile memory, the rewritable non-volatile memory (EEPROM) is:
When the first control data is transferred from the mask ROM, it has a third storage area in which a check code indicating that the same data has been transferred is written, and the initialization procedure is stored in the third storage area. The transfer of the first control data from the mask ROM is executed on condition that the check code does not exist. Alternatively, in the above control data storage method, when transferring the first control data stored in advance in the mask ROM to the first area of the rewritable nonvolatile memory (EEPROM), Check code indicating that the control data of the above has been transferred to the EEPROM
This check code is written to the predetermined address of E, for example, when the control data is transferred from the mask ROM when the microcomputer is powered on.
It is executed on condition that it does not exist in the predetermined address of the EPROM. In that case, E from the mask ROM that should be executed only once
The transfer of the first control data to the EPROM can be performed stably and reliably. Also, the first
Even if the control data of is updated as above,
This will not be overwritten by the old control data set in the mask ROM.

The electronic control unit basically comprises: a rewritable non-volatile memory (EEPROM), in which the first control data which can be commonly used for each model is stored. And a second storage area for storing second control data that is different for each model.
And a storage area of. In the control data storage method, the rewritable nonvolatile memory (EEPROM) storage area is divided into two areas, a first area and a first area. Stores the first control data that can be commonly used for each model, and stores the second control data that is different for each model in the second area. Even if such a method is adopted, the versatility as a one-chip microcomputer is preferably maintained. Moreover, by classifying the control data into the above-mentioned first and second control data and storing them in the corresponding areas of the EEPROM,
The maintainability of those data will also be greatly improved.

[0022]

FIG. 1 shows an embodiment of an electronic control unit having a one-chip microcomputer according to the present invention.

In the apparatus of this embodiment, the electronic control unit body 1 is an apparatus for electronically controlling the fuel injection amount and ignition timing of the engine in, for example, an automobile, and the one-chip microcomputer 10 is provided therein. Is provided.

The electronic control unit body 1 is also provided with an input / output interface (I / O) 2 and an external device connection interface (I / F) 4. Through these interfaces 2 and 4, The data transfer between the various sensors / actuators 3 and the one-chip microcomputer 10 and the data transfer between the external device 5 and the one-chip microcomputer 10 are realized. .

Here, the external device 5 is a device such as a personal computer having a data communication function. Here, in particular, regarding the control data of the model to be controlled by the device of the embodiment, (a) ) Data that can be commonly used for each model, that is, common data 6, and (b) Data that needs to be changed for each model, that is, model-specific data 7, are classified into two types of data. It is used as a device for transferring the classified control data to the one-chip microcomputer 10 as needed.

The common data 6 is, for example, the energization time determined by the characteristics of the ignition coil of the ignition device, the characteristics of the injector used in the fuel injection device, or the characteristics of the sensor for detecting the water temperature or oil pressure of the engine. and so on. In general, these actuators and sensors are commonly used regardless of the model, and even if the model is different, the control data indicating their characteristics need not be changed. However, in the future, some of these actuators and sensors are often changed due to cost reduction and the like. In such a case, the common data 6 is created according to the characteristics of those actuators and sensors and transferred to the one-chip microcomputer 10 through the external device 5.

On the other hand, the model-specific data 7 includes data such as engine ignition timing and fuel injection amount.
For each of these data, it is necessary to set different values according to the model to be controlled. Therefore, these model-specific data 7 are created as data according to the model to be controlled at the time of shipping, for example, and transferred to the one-chip microcomputer 10 through the external device 5.

Now, as shown in FIG. 1, the one-chip microcomputer 10 to which these control data are transferred has a CPU 11, a ROM 12, a RAM 13 and an E.
The EPROM 14 and the address data bus 15 for electrically connecting these elements and the interfaces 2 and 4 are integrated in one IC (LSI) chip.

Here, the ROM 12 is formed as the mask ROM described above, and its memory structure is shown in FIG.
The mode is shown schematically in (a). That is, in the memory structure of the ROM 12 shown in FIG. 2A, the initialization routine area 121 is an area in which the initialization routine to be executed first when the microcomputer 10 is powered on is set and registered, and the control program area 122 is An area in which various control programs as the electronic control device are set and registered.

Further, in the ROM 12, the common data area 123 is used as control data corresponding to the above-mentioned common data 6 at the time of development of the electronic control device which can be commonly used for each model to be controlled. This is an area where data is set and registered. The common data set in the area 123 will be automatically transferred to the EEPROM 14 at the first execution of the initialization routine, as described later.

The EEPROM 14 is a rewritable non-volatile memory as described above, and particularly has a memory structure as shown in FIG. 2B.

That is, as shown in FIG. 2B, the EEPROM 14 has two control data storage areas, a common data area 141 and a model-specific data area 142. Of these, the common data area 141 is
This is an area for storing common data automatically transferred from the ROM 12 or common data 6 transferred to the microcomputer 10 through the external device 5 when necessary. The model-specific data area 142 is used for the microcomputer 10 via the external device 5 at the time of shipment.
This is an area for storing the model-specific data 7 transferred to.

In the apparatus of this embodiment, the EEP is set according to the number of each of the common data and the model-specific data.
Address "Hx0000 (Hx indicates hexadecimal number)" of ROM 14 ~
The common data area 141 is allocated to the address "Hx1000", and the same EEPROM1
4. The model-specific data area 142 is allocated to the addresses “Hx1001” to “Hx2FFF”. Further, in particular, regarding the address “Hx1000”, this is set in the check code area 143, and the R is added to the address “Hx1000”.
A check code indicating that the common data from the OM 12 has been transferred is written.

FIGS. 3 and 4 show an example of the processing procedure of the above initialization routine executed when the power of the apparatus of the embodiment is turned on. Next, please refer to FIGS. 3 and 4 together. The operation mode of the apparatus of the embodiment, particularly when the power is turned on, will be described in more detail.

That is, if the electronic control unit of this embodiment is powered on, the CPU 11 in the one-chip microcomputer 10 first reads the initialization routine 100 stored in the area 121 of the ROM 12, and The routine 100 is executed in the procedure listed in.

In step 101, peripheral devices such as registers provided inside the microcomputer 10 and each input / output port of the microcomputer 10 are defined in a predetermined state.

Then, in step 102, the ROM
The checksum data set in the specific address in the same ROM 12 is used to check whether or not 12 is abnormal. Further, in step 103, it is checked whether or not the RAM 13 can be normally written or read, and in the next step 104, all the data in the RAM 13 is cleared in order to use the RAM 13 for subsequent control.

If it is determined in step 102 or step 103 that the ROM 12 or RAM 13 is abnormal, the process proceeds to step 105. This step 105 is an infinite loop, and when there is an abnormality in the ROM 12 or the RAM 13, it is determined that the microcomputer 10 itself cannot be used and the subsequent processing is stopped.

In step 106, the EEPROM
It is confirmed whether data is already stored in the common data area 141 of 14. This EEPROM 14 stores data HxF in all the areas before the data is stored.
F or Hx00 has been written.

Here, whether or not the common data is stored in the EEPROM 14 depends on whether the EEPROM 14 is the same or not.
It is determined whether or not a predetermined check code is registered in the above check code area 143 (address “Hx1000”).

Incidentally, in the apparatus of the embodiment, a code such as HxA5 is adopted as this check code,
If the code HxA5 is stored in the check code area 143, it is determined that the common data has already been written, and the process proceeds to step 110 (FIG. 4).

On the other hand, if this code HxA5 is not stored in the check code area 143, it is judged that the common data has not been written yet, and step 10
The common data automatic transfer process from 7 to step 109 is executed.

That is, in this common data automatic transfer processing, first, in step 107, the EEPROM 14 is used.
Clear all once. That is, the EEPROM 14
Bulk erase is performed by writing the data HxFF or Hx00 in all the storage areas. And then step 1
08, the common data set and stored in the ROM 12 at the mask stage is stored in the common data area 1 of the EEPROM 14.
41 to 41. At the end of the common data automatic transfer processing, the check code HxA
5 is the check code area 143 of the EEPROM 14
Write in (address "Hx1000"). The check code HxA5 once written in this way is not erased or overwritten unless bulk erase is performed again.

Now, the microcomputer 10 (CPU 11) that has completed the automatic common data transfer process or determined in step 106 that the common data has already been written, then proceeds to step 110.
(FIG. 4) The subsequent verification check processing is executed.

In this process, first, at step 110, it is checked whether or not there is any abnormality in the common data stored in the common data area 141 of the EEPROM 14 by the checksum data set in the specific address.

If it is determined that there is an abnormality in the check in step 110, the checksum error flag is set in step 113. On the other hand, when it is determined that there is no abnormality in the check in the same step 110, next, in step 111 and step 112, the above common condition is provided on the condition that the model-specific data exists in the model-specific data area 142 of the EEPROM 14. Perform a verify check similar to the data.

In the verify check in step 112 also, if it is determined that the model-specific data is abnormal, the checksum error flag is set in step 113.

If it is determined in step 110 that the common data is normal and that the model-specific data does not exist (step 111), or if the model-specific data exists, the same model-specific data exists. When it is determined that there is no abnormality in the data (step 112), the process proceeds to step 114.

At step 114, initial values required for various controls to be performed later are set in the RAM 13, and then at step 115, a timer inside the microcomputer 10 used for the control, a flag at the time of interruption, an input / output level. Etc. are set.

Then, in step 116, it is checked whether or not the checksum error flag is set. If the checksum error flag is set, that is, if the EEPROM 14 is abnormal, the process proceeds to step 117. Then, the subsequent interrupt request is prohibited.

Note that the processing prohibited here is only interrupt processing by a rotation signal or the like generated as a signal synchronized with the rotation of the engine, for example, and other various data processing is normally executed. That is, the above-mentioned EEPROM
Even if there is an abnormality in 14, it is due to an abnormality in the control data stored therein, and if the abnormality in the control data is avoided, the checksum error flag is set through the above step 113. Things will disappear. Therefore, by prohibiting only the interrupt processing and activating the other processing, the stored control data can be corrected.

On the other hand, if it is determined in step 116 that the checksum error flag is not set, that is, if the EEPROM 14 has no abnormality, the condition for generating an interrupt is set in step 118. By setting these conditions, the subsequent control based on the interrupt will be normally executed.

It should be noted that, when executing the above control, it is assumed that only the control data stored in the EEPROM 14 is used in the apparatus of the embodiment. Ie ROM
Although common data is stored in 12 as well,
It is never used directly.

As described above, according to the apparatus of this embodiment, the ROM is previously stored through the initialization routine.
Common data stored in 12 is automatically EEP only once
It is transferred and stored in the ROM 14.

Moreover, the data stored in the EEPROM 14, whether it is common data or model-specific data, can be changed through the external device 5 when necessary.

Further, especially regarding the common data, since the necessity of the transfer from the ROM 12 is judged by the check code (HxA5), the contents thereof are determined by the external device 5.
Even if it has been updated through, the updated contents will not be overwritten by the contents of the old common data set in the ROM 12.

For this reason, in the apparatus of the embodiment, for example, in the (1) development stage of the one-chip microcomputer 10, the control program and the common data required for the electronic control apparatus including the initialization routine are stored. Are stored in the ROM (mask ROM) 12. (2) The specifications of the model-specific data 7 are fixed by the shipping stage of the product, and the fixed data is stored in the EEPROM 14 through the external device 5. That is, at this stage, the control characteristic specified for the model to be controlled is set. (3) Even when the specification is changed in the data determined to be common data at the development stage, like the model-specific data 7, the data is stored in the EEPROM 14 as the common data 6 through the external device 5 at the shipping stage, for example. That is, the ROM 1
The old common data automatically transferred from 2 is updated by this common data 6. Of course, in this case, it is not necessary to change the data itself stored in the ROM 12. It becomes possible to achieve flexible and versatile use such as.

According to the apparatus of the same embodiment, the EEP
The control data to be stored in the ROM 14 is classified into the common data and the model-specific data, and basically, only the model-specific data among these is the data to be actually written at the time of shipping. Therefore, the number of data to be written is greatly reduced, and as described above: It takes a long time to write the control data in the EEPROM, which deteriorates the productivity. -There is a high possibility that the control data to be written in the EEPROM will be set incorrectly. Problems such as the above will be resolved by themselves.

In the apparatus of this embodiment, the EEP
The ROM 14 is said to be built in the one-chip microcomputer 10, but this EEPROM does not necessarily have to be in the same microcomputer 10.
It may be separately provided outside thereof.

As described above, even when the EEPROM 14 is provided outside the one-chip microcomputer 10, the configuration shown in FIG. 1 is electrically satisfied, and the equivalent initialization routine is executed. In that case, the same effect as above can be naturally obtained.

Further, in the apparatus of the embodiment, the ROM 12 to the EEPROM is passed through the initialization routine.
Although the transfer of the common data to 14 is automatically executed, such a data transfer procedure does not necessarily have to be defined in the initialization routine.

That is, the processing procedure corresponding to the automatic transfer processing of common data in steps 107 to 109 of FIG. 3 is executed at least once at any stage before the common data is updated from the outside. Just do it.

If the automatic transfer processing of the common data is executed only once, EEPRO
It is not necessary to provide the check code area 143 in M and to write the check code in the area 143.

Even in those cases where the common data automatic transfer process is not performed in the initialization routine, the above-described operation and effect of the electronic control unit can be achieved similarly.

Further, in the apparatus of the embodiment, the EEPROM is
The common data stored in the 14 common data areas 141 is R
It is supposed that the data is transferred from the OM 12 or through the external device 5, but the electronic control device basically has: -A common data area in which the common data is stored and a model-specific data area in which the model-specific data is stored. The versatility of the one-chip microcomputer 10 can be preferably maintained even by providing the EEPROM having the respective and. Moreover, by classifying the control data into the common data and the model-specific data and storing them in the corresponding areas of the EEPROM, the maintainability of these data can be greatly improved.

Further, in the above embodiment, for the sake of convenience, when the electronic control device and the control data storing method according to the present invention are applied to a device for electronically controlling the fuel injection amount and ignition timing of an engine in, for example, an automobile, etc. However, the present invention can be similarly applied to any other electronic control device as long as the electronic control device includes a one-chip microcomputer and controls a plurality of types of different devices.

In this specification, the EEPROM means all electrically rewritable non-volatile memories, specifically, EAROM (Electrically Alterab).
le ROM: Electrically Alterable ROM) or F
EEPROM (Flash Electrical Erasable and Progra
mmable ROM: Flash, electrical, erasable, and programmable ROM) are all included.

[0068]

As described above, according to the present invention, the productivity is deteriorated due to the increase in the number of data to be written in the EEPROM, the data setting error, etc., without impairing the versatility of the one-chip microcomputer. Can be effectively prevented.

Further, according to the present invention, the maintainability of the data is also greatly improved, and it becomes possible to promptly deal with the change of the control specifications.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an electronic control device including a one-chip microcomputer according to the present invention.

FIG. 2 is a mask R used in the electronic control unit of the embodiment.
3 is a schematic diagram schematically showing each memory structure of an OM and an EEPROM.

FIG. 3 is a flowchart illustrating a main routine of an initialization routine executed when the power is turned on in the electronic control unit of the embodiment.
6 is a flowchart showing a processing procedure for checking a check code of the EPROM and transferring control data from the mask ROM to the EEPROM.

FIG. 4 is a flowchart showing a main routine of an initialization routine executed when the power is turned on in the electronic control unit of the embodiment.
6 is a flowchart showing a processing procedure for a verify check of an EPROM.

[Explanation of symbols]

1 ... Electronic control unit main body, 2 ... Input / output interface,
3 ... Sensor / actuator, etc., 4 ... External device connection interface, 5 ... External device, 6 ... Common data, 7 ... Model-specific data, 10 ... One-chip microcomputer,
11 ... CPU, 12 ... ROM (mask ROM), 13 ...
RAM, 14 ... EEPROM, 15 ... Address data bus, 121 ... Initialization routine area, 122 ... Control program area, 123 ... Common data area, 141 ...
Common data area, 142 ... Model-specific data area, 143 ...
Check code area.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location F02D 45/00 376 B G11C 16/06

Claims (6)

[Claims] 1. An electronic control unit for controlling a plurality of types of different devices, comprising a one-chip microcomputer in which a microcomputer having a CPU and a mask ROM is mounted on one chip, and comprising a rewritable nonvolatile memory. The rewritable nonvolatile memory has a first storage area for storing first control data that can be commonly used for each model and a second storage area for storing second control data that is different for each model. 2 storage areas, and the mask ROM has a storage area in which the first control data transferred to the first storage area of the rewritable nonvolatile memory is preregistered. An electronic control unit with a one-chip microcomputer. 2. The electronic control device according to claim 1, wherein the mask ROM is rewritable only once, the first control data being pre-registered by being executed when power is supplied to the microcomputer. First non-volatile memory
Of the mask RO, the rewritable non-volatile memory has a storage area in which an initialization procedure to be transferred to the storage area is written.
At the time of transferring the first control data from M, it has a third storage area in which a check code indicating that the same data has been transferred is written, and the initialization procedure described in the mask ROM is An electronic control device comprising a one-chip microcomputer, wherein the transfer of the first control data is executed on condition that a check code does not exist in the storage area. 3. An electronic control device for controlling a plurality of types of different devices, comprising a one-chip microcomputer in which a microcomputer having a CPU and a mask ROM is mounted on one chip, and comprising a rewritable nonvolatile memory. The rewritable nonvolatile memory has a first storage area for storing first control data that can be commonly used for each model and a second storage area for storing second control data that is different for each model. An electronic control unit comprising a one-chip microcomputer having two storage areas. 4. A one-chip microcomputer in which a microcomputer having a CPU and a mask ROM is mounted on one chip, and a rewritable nonvolatile memory mounted inside or outside the one-chip microcomputer. In addition, in an electronic control device for controlling a plurality of types of different devices, the control data of each of the devices can be commonly used for each model, and the second control data can be used for each model. And the storage area of the rewritable nonvolatile memory is divided into a first area in which the first control data is stored and a second area in which the second control data is stored. Then, the first control data stored in the mask ROM in advance is transferred to the first area of the rewritable nonvolatile memory, The second control data and the first control data that need to be changed are separately prepared and transferred to corresponding areas of the rewritable nonvolatile memory through an appropriate external device when necessary. A method for storing control data of an electronic control device comprising a one-chip microcomputer. 5. A check indicating that the first control data has been transferred when the first control data stored in advance in the mask ROM is transferred to the first area of the rewritable nonvolatile memory. The code is written together with a predetermined address of the non-volatile memory, and the transfer of the first control data from the mask ROM is such that the check code does not exist at the predetermined address of the rewritable non-volatile memory. 5. A control data storage method for an electronic control device comprising the one-chip microcomputer according to claim 4, which is executed under the condition of. 6. A one-chip microcomputer in which a microcomputer having a CPU and a mask ROM is mounted on one chip, and a rewritable nonvolatile memory mounted inside or outside the one-chip microcomputer. In an electronic control device for controlling a plurality of different devices, the rewritable non-volatile memory storage area is divided into two areas, a first area and a second area. A one-chip microcomputer characterized by storing first control data that can be commonly used for each model and storing second control data that is different for each model in the second area. Control data storage method for electronic control unit.