JPH0436048A - Electronic controller for vehicle - Google Patents

Abstract

PURPOSE:To apply one microcomputer to many kinds of vehicles and reduce control mandays to a large extent so as to reduce the cost by storing common specification data including a control program in first memory installed in an one-chip microcomputer, and storing different data for each kind of vehicle in second memory. CONSTITUTION:Common specification data including a control program are stored in first memory 7 installed in an one-chip microcomputer 2 and different data for each kind of vehicle are stored in second memory 10. The common specification data including the control program incapable of being changed and stored in the first memory 7 are used in common to each kind of vehicle and the control corresponding to each kind of vehicle is carried out by reloadable data for each kind of vehicle stored in the second memory 10. The first memory 7 is used as a mask ROM and the common specification data including the control program is stored by masking process in manufacturing processes and the second memory is used as a ROM in which data is electrically reloadable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicle electronic control device comprising a one-chip microcomputer.

[Background Art] In recent years, microcomputers have been installed in vehicles such as automobiles, and since then, various control functions including engine control have been dramatically improved.

The microcomputer installed in this car is CP
In contrast to general-purpose microcomputers that are composed of several chips such as U, ROM, RAM, and peripheral I10, many use one-chip microcomputers in which each element is integrated into one IC, and in this case, The built-in ROM usually uses a mask ROM.

Since programs and data are written to this mask ROM during the IC wafer manufacturing stage, it is suitable for mass production and has high reliability, but it has little cost advantage for small volume production.
In addition, if the system specifications change due to parallel development of other control components or specifications change due to improvements, the mask design will need to be changed in order to rewrite the previously written program or data. Not only does this require additional time (several months) and additional costs, but the one-chip microcomputers themselves in stock are wasted, leading to an increase in product costs.

To deal with this, Japanese Patent Application Laid-Open No. 60-159353 discloses a writable FR that retains data even when the power is turned off.
A first memory consisting of OM is externally attached to the one-chip microcomputer to store control programs for controlling various operating means governing the operation of the automobile, and a non-writable mask RO inside the one-chip microcomputer is used.
A technique for storing control data in a second memory consisting of M is disclosed.

[Problems to be Solved by the Invention] However, once the specifications are fixed and debugging is completed, the vehicle control program can be made to be common to vehicle models with similar specifications by changing control data that differs for each vehicle model. In this case, if the control data is stored in the mask ROM, it is not only impossible to change it, but also makes it difficult to quickly respond to small specification changes even in the same vehicle model.

In addition, when PROM is used to store the same control program that is common to many car models, it is significantly disadvantageous in terms of cost compared to mask ROM.Furthermore, attaching PROM externally to a one-chip microcomputer requires less assembly man-hours. In addition to this, it also requires a large number of man-hours in terms of parts management, leading to an increase in costs.

[Object of the Invention] The present invention has been made in view of the above circumstances, and allows one microcomputer to be commonly applied to many vehicle models, and can also be quickly applied to small-scale specification changes. The purpose of the present invention is to provide a vehicle electronic control device that is compatible with the above and can reduce costs.

[Means for Solving the Problems] In order to achieve the above object, an electronic control device for a vehicle according to the present invention includes a first memory in which data cannot be written, and a first memory that retains data even when the power is turned off and can rewrite this data. The second
In a vehicle electronic control device comprising a microcomputer, the microcomputer is connected to the first memory that stores common specification data including a control program, and the second memory that stores data that differs depending on the vehicle type. The first memory is composed of a mask ROM, and the second memory can be electrically rewritten as a one-time programmable ROM. It is constructed from ROM.

[Function] In the vehicle electronic control device configured as described above, common specification data including a control program is stored in the first memory built in the one-chip microcomputer, and data different for each vehicle type is stored in the second memory. let

The common specification data including the unchangeable control program stored in the first memory is commonly used for each vehicle model, and the rewritable data for each vehicle model stored in the second memory is used for each vehicle model. Execute the corresponding control.

Further, the first memory may be a mask ROM to store common specification data including the control program through a masking process at the manufacturing stage, and the second memory may be a ROM in which data can be electrically rewritten, for each vehicle model. Different data is stored by writing in a one-time program at the time of shipment.

[Embodiments of the invention] Hereinafter, the present invention will be described in detail with reference to the drawings.

The drawing is a configuration diagram of an electronic control device according to the present invention, and in the drawing, reference numeral 1 indicates an electronic control unit (ECU) mounted on a vehicle such as an automatic type.

This ECLJI performs, for example, engine air-fuel ratio control (fuel injection control), ignition timing control, etc., and has a one-chip microcomputer 2 as its core, and an input processing circuit 3 that processes input signals from various sensors, switches, etc.
, an A/D converter 4 that converts analog input signals from sensors into digital signals, an output processing circuit 5 that drives various actuators, a power supply circuit 6, and the like.

The one-chip microcomputer 2 has a CPU 6,
A mask RoM 7, a RAM 8, a timer 9, an electrically rewritable PROM (EEPROM) 10, a counter 11, an I10 port 12, etc. are integrated into one chip, and each of these elements is connected to a data bus 13. ,
They are connected to each other by an address bus 14.

Note that the A/D converter 4 may be built into the one-chip microcomputer 2.

The one-chip microcomputer 2 has a mask RO
The first memory such as M7 stores control programs such as fuel injection control and ignition timing control that are common to each vehicle model, as well as fixed data that is common to each vehicle model such as calculation constants. In the second memory,
For example, control data unique to each vehicle type, such as a basic fuel injection amount map, an ignition timing map, and control constants, are stored.

The data common to each vehicle model, including this control program, is
The one-chip microcomputer 2 is stored in the mask ROM 7 in advance at the manufacturing stage, and the one-chip microcomputer 2 stores only the control program and fixed data common to each vehicle type in the mask ROM 7 at the initial stage of the product. and the above EEPROMIO
No meaningful data is stored in the .

In other words, the one-chip microcomputer 2 used for control only has data that is common to each vehicle type before it is installed in a car and shipped to the market. By storing it in the mask ROM 7 at the manufacturing stage of No. 2, it can be advantageous in terms of cost.

On the other hand, data specific to each car model is subject to specification changes during the period from the development stage to actual production and shipment, and furthermore, for car models whose specifications have not been finalized,
It is impossible to store data in advance at the manufacturing stage of the one-chip microcomputer 2.

Therefore, such vehicle type-specific data is stored in the EEPR in the one-chip microcomputer 2 at the time of product shipment.
By being able to write to OMIO, it can be applied to many car models, and ultimately the one-chip microcomputer 2 can have different contents for each car model. This shortens the development period and also allows external FR
Since no OM is required, costs can be reduced, and since all the one-chip microcomputers 2 in stock are the same, the number of man-hours for managing parts can be reduced.

In this case, the data specific to the vehicle model only needs to be written once at the time of product shipment, and such FROMs include one-time program ROMs (OTPROMs) such as fuse-cutting type and diode-breaking type ROMs; , PROM (UVEPROM) + which can erase and rewrite data with ultraviolet rays, meaning that data will not be written again after the product is shipped, or electrically erase and rewrite data like EEPROM 10 above. A FROM that can be used can also be used as a one-time program compatible ROM.

The above-mentioned EEPROMIO does not require special equipment such as a large amount of ultraviolet light generation source, and can be more advantageous in terms of handling cost than the above-mentioned UVEPROM.

In the ECtJ 1 having such a configuration, signals from various sensors and switches are taken into the one-chip microcomputer 2 via the input processing circuit 3,
Further, the digital signal converted by the A/D converter 4 is taken into the microcomputer 2.

In the one-chip microcomputer 2, the CP
Control 70 stored in the mask ROM 7 at U6
According to the above-mentioned R
Store in AM8.

Next, using this engine speed, intake air amount, or intake pipe pressure as parameters, the above E is determined according to the vehicle type.
The basic fuel injection amount map stored in the EPROMIO is searched to set the basic fuel injection amount, and the basic fuel injection amount and engine speed are used as parameters to be stored in the EEPROMIO in accordance with the vehicle type. Search for the available ignition timing map and set the basic ignition timing.

Thereafter, the basic fuel injection amount and basic ignition timing are corrected using parameters related to the engine operating state from sensors and switches, and the injector is transmitted from the output boat of the I10 boat 12 via the output processing circuit 5 at a predetermined timing. , igniter, and other actuators to perform fuel injection control, ignition timing control, etc.

[Effects of the Invention] As explained above, according to the present invention, common specification data including a control program is stored in the first memory built in the one-chip microcomputer, and data different for each vehicle model is stored in the second memory. Because it memorizes information, one microcomputer can be applied to many vehicle models, which not only greatly reduces management man-hours and costs, but also flexibly supports high-mix, low-volume production. can achieve significant cost reductions.

Furthermore, excellent effects can be achieved, such as being able to quickly respond to small-scale specification changes, such as data content changes during development or data content changes for improvement.

[Brief explanation of drawings]

The drawing is a configuration diagram of an electronic control device included in the present invention. 1...Electronic control device 2...One-chip microcomputer 7...First
memory (mask ROM) 10, second memory (EEP
ROM)

Claims (2)

[Claims] (1) A first memory that cannot write data, and a second memory that retains data even when the power is turned off and that can rewrite this data.
In a vehicle electronic control device comprising a microcomputer, the microcomputer is connected to the first memory that stores common specification data including a control program, and the second memory that stores data that differs depending on the vehicle type. An electronic control device for a vehicle comprising a one-chip microcomputer having a built-in memory. (2) The vehicle according to claim 1, wherein the first memory is composed of a mask ROM, and the second memory is composed of an electrically rewritable ROM as a one-time program compatible ROM. electronic control unit.