JP3174354B2 - Vehicle control system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle control system using a plurality of microcomputers.

[0002]

2. Description of the Related Art In recent years, in many vehicles such as automobiles, a plurality of computers are mounted and controlled, and for example, Japanese Patent Application Laid-Open No. 61-49154 discloses first and second computers.
A technology is disclosed that includes a microcomputer of the type described above and performs a sharing process on a plurality of types of control items.

A microcomputer mounted on an automobile includes a CPU, a ROM, a RAM, and peripheral I / O.
In general, there are many one-chip microcomputers in which each element is integrated in one LSI, compared to a general-purpose microcomputer constituted by several chips such as a single chip. In this case, a built-in ROM usually includes a mask. ROM is adopted.

[0004] The mask ROM, since the program and data are written in the wafer manufacturing stage of the LSI of the one-chip microcomputer, suitable for mass production, although reliable, low cost advantage in small production, system specifications It takes several months for the lead time from the decision of the product to the completion of the product, and there is little freedom for specification changes during the development period. On the other hand, one-time program R
OM has a slightly lower cost advantage in mass production
On the other hand, the lead time until the product is completed is short.

To cope with this, Japanese Patent Laid-Open Publication No. 61-6455
In Japanese Patent Application Publication No. 6-205, an electronic control unit is provided with an internal ROM in which information indicating a general-purpose control program resides, and an external ROM in which information representing a control sequence for executing predetermined control is expressed in an intermediate language format. Accordingly, a technique for improving the followability of a specification change has been disclosed.

[0006]

However, usually,
In the specification of the one-chip microcomputer, the last one to be determined is the control data. Even if the control program specification is fixed and debugging is completed, if the control data is not determined, the manufacturing of the one-chip microcomputer Regardless, the period from development to commercialization is prolonged.

[0007] The present invention has been made in view of the above circumstances, and a mask ROM from determination of control specifications of a vehicle to commercialization.
It is an object of the present invention to provide a vehicle control system capable of reducing the influence of a lead time required for manufacturing a vehicle and shortening a development period.

[0008]

Means for Solving the Problems To achieve the above object,
Therefore, the invention according to claim 1 is a control device mounted on a vehicle.
In addition, a first microcomputer and a second microcomputer
And a computer, and the data between the two microcomputers.
In the control system of a vehicle that executes data transfer,
The mask ROM in the microcomputer 1
Microcomputer with one-time programmable R
OM respectively, above the first microcomputer
The fixed data represented by the control program is stored in the mask ROM.
Data on the second microcomputer
One-time programmable ROM controls specific to each model
Writes the data, and the second microcomputer
Write to the above one-time programmable ROM at startup
Control data transferred to the first microcomputer.
The first microcomputer sends control data
Is transferred to normal control after the completion of reception .

[0009] The invention according to claim 2 provides the invention according to claim 1.
In the description, the second microcomputer is
Transmission of control data to the first microcomputer is completed.
When completed, calculate the sum check number of the transmitted data
The sum check number and the first microcomputer
Compare the checksum sent from the
If the number of checksums and the checksum do not match, the control data
The checksum and the checksum are
If it does, the control start command is sent to the first microcomputer.
And the second microcomputer sends a command
Calculate the sum check of the received data, and
To the computer and from the first microcomputer
To the normal control after receiving the above control start command
Characterized in that it.

[0010]

According to the first aspect of the present invention, a control program is provided at a manufacturing stage.
The fixed data represented by the RAM
Data stored in the mask ROM of the
The time of completion of the first microcomputer
One-time programmer for the second microcomputer
Write to the ROM. And the second microcomputer
Data is written to the one-time programmable ROM at startup.
Control data stored in a first microcomputer
And the first microcomputer transmits the control data
After the reception of is completed, the process shifts to the normal control.

According to the invention described in claim 2, the second mask is provided.
Microcomputer goes to the first microcomputer
When the transmission of the control data of
Check number and the number sent from the first microcomputer.
Compare with the incoming checksum and they do not match
In such a case, the control data is transmitted to the second computer again.
If the number of checksums matches the checksum
Control start command to the first microcomputer
Send. Then, the second microcomputer receives the
The first microcontroller calculates the sum check of the
To the computer and from the first microcomputer.
After receiving the control start command, the control shifts to the normal control.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. The drawings show one embodiment of the present invention, and FIG.
FIG. 2 is a flowchart showing a startup processing procedure on the U side, FIG. 2 is a flowchart showing a startup processing procedure on the main CPU side,
FIG. 3 is a circuit configuration diagram of the control device.

In FIG. 3, reference numeral 1 denotes an electronic control unit (ECU) mounted on a vehicle such as an automobile.
The CU 1 includes two one-chip microcomputers, that is, a first microcomputer 2 that performs, for example, engine air-fuel ratio control (fuel injection control), ignition timing control, and the like, and a second microcomputer 3 that performs, for example, knock detection processing. And the center,
An input processing circuit that processes input signals from various sensors and switches (not shown), an A / D converter that converts analog input signals from the sensors into digital signals, an output processing circuit that drives various actuators, and A power supply circuit and the like are added.

The first microcomputer 2 comprises a main CPU 4, a mask ROM 5, a RAM 6, a timer 7,
An input / output (I / O) interface 8 and a serial interface (SCI) 9 are integrated in one chip, and these elements are connected to each other by a bus line 10.

Further, the second microcomputer 3
Is a sub CPU 11, one-time programmable ROM
(OTPROM) 12, RAM 13, timer 14, I / O
The O interface 15 and the SCI 16 are integrated in one chip, and these elements are connected to a bus line 17.
The one-time programmable ROM 12 includes, for example, UVEPROM, EE
A PROM or the like is employed.

The first microcomputer 2 and the second microcomputer 3 are connected to each other via a serial line for transmitting and receiving a clock signal CLOCK, a transmission signal TX, and a reception signal RX via SCIs 9 and 16. In synchronization with the clock signal CLK supplied from the first microcomputer 2, a clock synchronous bidirectional communication is performed between the first microcomputer 2 and the second microcomputer 3.

In the first microcomputer 2, fixed data such as control programs such as fuel injection control and ignition timing control are stored in a mask ROM 5 in a manufacturing stage.
On the other hand, the second microcomputer 3 is, for example,
Vehicle-specific control data such as a basic fuel injection amount map, an ignition timing map, and control constants are stored in the OTPROM 12 in accordance with the product completion time of the first microcomputer 2.
Is written to.

The first microcomputer 2 having the mask ROM 5 requires several months for the manufacturing period,
The second microcomputer 3 having the OTPROM 12 can be manufactured in a fraction of the period of the first microcomputer 2.

Therefore, after the specification of the control program is determined and the debugging is completed, the first microcomputer 2 can be immediately manufactured. During the manufacturing of the first microcomputer 2, the second microcomputer 2 is manufactured. The control data to be written into the OTPROM 12 of No. 3 can be determined by experiments or the like.

This shortens the overall development period,
In addition, the cost can be significantly reduced by reducing the total man-hours.

Next, in the ECU 1 having such a configuration, the second microcomputer 3 sends the first
The control data is transferred to the microcomputer 2, and then the control is shifted to the normal control. Hereinafter, the startup process will be described.

The flowchart shown in FIG. 1 is a startup process executed by the sub CPU 11 of the second microcomputer 3. First, in step S101, the OTPRO is executed.
The control data in M12 is transmitted to the first microcomputer 2 via the SCI16.

Next, the process proceeds to step S102, where it is checked whether or not the transmission of all control data has been completed. If the transmission has not been completed, the process returns to step S101 to continue the transmission of the control data. If finished, step
Proceed to S103.

In step S103, the checksum of the transmitted data is calculated, and in step S104, the checksum transmitted from the main CPU 4 of the first microcomputer 2 is received.

In step S105, the checksum of the main CPU is compared with the checksum of the transmission data.
It is checked whether or not these checksums match, and if they do not match, the process returns to step S101, where O
The control data in the TPROM 11 is transmitted again.

In step S105, the main CPU
When the checksum of the transmission data and the checksum of the transmission data match, the process proceeds to step S106, where a control start command is transmitted to the main CPU 4 and the process shifts to normal control.

On the other hand, on the first microcomputer 2 side, the processing at the time of startup shown in FIG. 2 is executed by the main CPU 4, and in step S 201, the sub CPU 1
The control data from the first side is received and stored in the RAM 6.

Next, in step S202, it is checked whether or not all the control data has been received. If the reception has not been completed, the flow returns to step S201 to continue receiving the control data. If the processing has been completed, the process proceeds to step S203.

In step S203, the checksum of the received data is calculated. In step S204, the calculated checksum is transmitted to the sub CPU 11, and then, in step S205
Then, the control waits for a control start command transmitted from the sub CPU 11, and after receiving the control start command, shifts to the normal control.

It should be noted that the present invention is not limited to the embodiment, and the first microcomputer 2 and the second microcomputer 3 may be separate ECUs. It may be independent.

[0031]

As described above, according to the first aspect of the present invention, the mask RO is provided in the first microcomputer.
M is provided with a one-time programmable ROM in the second microcomputer, so that the fixed data represented by the control program is stored in the mask ROM of the first microcomputer at the manufacturing stage, and the control data unique to each vehicle model is stored in the first microcomputer. The data can be written to the one-time programmable ROM of the second microcomputer at the time of completion of the product of the first microcomputer. In other words, the
Control by mask ROM provided in one microcomputer
Since storing fixed data represented in the program, a first microcomputer requiring production period is after the end of the usage decision and debugging of the control program, Ru can immediately take the production. And the second microcompilation
One-time programmable ROM for each car
Since the type-specific control data is written, the control data to be written to the one-time programmable ROM of the second microcomputer during the manufacturing period of the first microcomputer can be determined by experiments or the like. Therefore, the influence of the lead time required for manufacturing the mask ROM from the determination of the control specifications of the vehicle to the commercialization can be reduced, the entire development period can be shortened, and the cost can be significantly reduced by reducing the total man-hour. Then, the second microcomputer transfers the control data written in the one-time programmable ROM to the first microcomputer at the time of startup, and the first microcomputer normally executes control data reception after completing the reception of the control data. Since the control is shifted to the control, even if the fixed data represented by the control program and the control data specific to each vehicle type are individually stored in the first microcomputer and the second microcomputer respectively, the control can be reliably performed without any trouble. Can be performed. According to the second aspect of the present invention, when the transmission of the control data to the first microcomputer is completed, the second microcomputer receives the sum check number of the transmitted data and the number of transmitted checksums from the first microcomputer. The checksum is compared with the incoming checksum, and if they do not match, the control data is
When the number of checksums matches the checksum, a control start command is transmitted to the first microcomputer. Then, the second microcomputer calculates the sum check of the received data, transmits the sum check to the first microcomputer, and receives the control start command from the first microcomputer,
Since the control is shifted to the normal control, in addition to the effect of the first aspect of the invention, when the control is executed by the first microcomputer, essential control data is surely transferred from the second microcomputer to the first microcomputer. The control can be started after being incorporated in the control, and the reliability of the control can be significantly improved.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a startup procedure of a sub CPU.

FIG. 2 is a flowchart showing a startup processing procedure on the main CPU side;

FIG. 3 is a circuit configuration diagram of a control device.

[Explanation of symbols]

 2 First microcomputer 3 Second microcomputer 5 Mask ROM 12 One-time programmable ROM

Claims (2)

(57) [Claims] A first microcomputer is provided to a control device mounted on a vehicle.
A microcomputer and a second microcomputer
To transfer data between both microcomputers.
In a vehicle control system, a mask ROM is stored in the first microcomputer.
One-time programmer for the second microcomputer
Each of which is equipped with a controllable ROM, and is controlled by the mask ROM of the first microcomputer.
In addition to storing fixed data represented by programs,
The one-time program of the second microcomputer
The control data unique to each vehicle type is written into the mable ROM, and the second microcomputer starts up the
The control data written in the time programmable ROM
Data to the first microcomputer and the first microcomputer
The microcomputer has completed receiving the control data
After control of the vehicle, characterized in that the transition to the normal controls
Stem . 2. The second microcomputer according to claim 1 , wherein
Transmission of control data to the first microcomputer is completed.
When completed, calculate the sum check number of the transmitted data
The sum check number and the first microcomputer
Compare the checksum sent from the
If the number of checksums and the checksum do not match, the control data
The checksum and the checksum are
If it does, the control start command is sent to the first microcomputer.
And the second microcomputer transmits a sum of the received data.
Calculate check and send to first microcomputer
And the control start command from the first microcomputer.
2. The vehicle control system according to claim 1 , wherein, after receiving the command, the control shifts to normal control .