JPH09252267A - Electronic controller for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent defect of communication capability and connection by selecting automatically half duplex communication or full duplex communication so as to obtain the proper communication system depending on the communication system of an electronic device connected externally. SOLUTION: An output port of an output interface is set to a low level and a full duplex communication reception buffer is connected to a receive status register RSR of a serial communication interface SCI to check whether or not a receive data register RDR has reception data. When the RDR has reception data, the full duplex communication mode is selected and when no reception data are stored in the RDR and data read from a half duplex communication reception buffer via an input port of an input interface represents initializing procedure of the half duplex communication, the output port of the output interface is set to a high level, the half duplex communication reception buffer is connected to the RSR to select the half duplex communication (S108). Thus, the half dulex communication or the full duplex communication is automatically selected depending on the communication system of an electronic device connected externally to obtain a proper communication system thereby preventing defect of the communication capability and connection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle electronic control device capable of exchanging data with an external electronic device by serial communication.

[0002]

2. Description of the Related Art In recent vehicles such as automobiles, it is no exaggeration to say that it is standard to equip a control system with a complicated electronic control system and to mount an electronic control device by a microcomputer. Is capable of exchanging data with an external electronic device via a serial communication interface.

As an external electronic device connected to an on-vehicle electronic control device, a development support device for creating various control programs, data setting, debugging, etc. at the time of developing the on-vehicle electronic control device, for completion inspection There are various electronic devices, a failure diagnosis device for failure diagnosis in the market, etc., and a technique relating to communication between this failure diagnosis device and an on-vehicle electronic control device is disclosed in Japanese Patent Publication No. 7-76737 by the applicant. There is.

[0004]

By the way, in a failure diagnosis device connected to an in-vehicle electronic control unit, an international system which considers the capabilities of various in-vehicle electronic control units in comparison with a general full-duplex communication system in an electronic device. Standards (eg ISO 9141-198
9 Road vehicles-Diagnostic systems-Requirements fo
In many cases, half-duplex communication is adopted along with the interchange of digital information.

Therefore, by making the communication system of the on-vehicle electronic control device half-duplex communication, it is possible to secure communication to the failure diagnosis device at the time of failure diagnosis in the market, but it is not possible to use a development support device or a limited device that handles a large amount of data. The half-duplex communication system must be used even for the completed inspection electronic device that must be inspected within a given time, and the communication capacity will be insufficient due to the large amount of data to be handled and the data transmission speed. On the contrary, if the communication system of the on-vehicle electronic control device is full-duplex communication, the communication capability at the time of development and completion inspection can be secured, but a problem occurs in communication with the failure diagnosis device in the market.

The present invention has been made in view of the above circumstances, and automatically switches between half-duplex communication and full-duplex communication in accordance with the communication system of an electronic device connected to the outside to provide an appropriate communication system. It is an object of the present invention to provide an electronic control device for a vehicle, which can prevent troubles in communication capability and connection.

[0007]

According to the first aspect of the present invention,
An electronic control device for a vehicle, which is mounted on a vehicle and is capable of exchanging data by serial communication with an externally connected electronic device, stores data from the electronic device as shown in the basic configuration diagram of FIG. Communication unit having a receiving unit for storing data to be transmitted to the electronic device independently of the receiving unit, a data transmission system from the electronic device to the receiving unit, and the electronic unit for transmitting data from the transmitting unit. A transmission system switching means for selectively switching a data transmission system to the device between two systems independent from each other and one system for both reception and transmission, and when the electronic device is connected, data is transmitted from the electronic device. On the basis of the full-duplex communication method or the half-duplex communication method, the transmission system switching means switches the data transmission systems to each other. The communication means enables bidirectional communication with the electronic device in a state where two independent systems are used, and when it is determined that the system is a half-duplex communication system, the transmission system switching means is used for both reception and transmission of the data transmission system. 1
And a communication setting unit that enables bidirectional communication by the communication unit in a systematic state.

According to a second aspect of the present invention, in the first aspect of the present invention, as shown in the basic configuration diagram of FIG. 1B, the transmission system switching means includes the transmission unit as a first data transmission system. Connected to the first receiver via the first switch means which is turned on and off by the communication setting means.
And a second data transmission system which is different from the first data transmission system via the second switch means which is turned on and off by the communication setting means.

According to a third aspect of the present invention, in the first aspect of the invention, as shown in the basic configuration diagram of FIG. 1C, the communication setting means sets the data transmission systems to each other by the transmission system switching means. When it is determined that the communication system of the electronic device is the full-duplex communication system based on the data stored in the receiving unit in a state where the two independent systems are provided, and it is determined that the communication system is not the full-duplex communication system, The communication system of the electronic device is half-duplex based on the data read from the electronic device without passing through the receiving section in a state in which the data transmission system is set to one system for both reception and transmission by the transmission system switching means. It is characterized by determining whether or not it is a communication method.

According to a fourth aspect of the present invention, in the second aspect of the invention, the first switch means is a first analog switch and the second switch means is a second analog switch. Is characterized by.

That is, according to the first aspect of the invention, when an external electronic device is connected, the communication system of the external electronic device is full-duplex communication or half-duplex communication based on the data from this electronic device. If it is determined to be a full-duplex communication method, the data transmission system is set to two independent systems to enable bidirectional communication with an external electronic device. The transmission system is set to one system for both reception and transmission to enable bidirectional communication with an external electronic device.

In this case, in the invention described in claim 2, the transmitter of the communication means is connected to the first data transmission system, and the receiver of the communication means is connected to the first data transmission system via the first switch means. And a second data transmission system, which is a system different from the first data transmission system, via the second switch means. Then, the first switch means is turned off,
By turning on the second switch means, the data transmission system is set to two systems in which reception and transmission are independent of each other, and
By turning on the switch means and turning off the second switch means, the data transmission system can be used for both reception and transmission.
System. According to the third aspect of the invention, the communication system of the external electronic device is the full-duplex communication system based on the data stored in the receiving section of the communication means in the state where the data transmission system is set to two independent systems. When it is determined that it is not the full-duplex communication method, the data transmission system is set to one system for both reception and transmission, and the data is read from the external electronic device without passing through the reception unit of the communication means. It is determined whether the communication method is the half-duplex communication method based on the data.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 2 to 4 show an embodiment of the present invention, FIG. 2 is a flow chart of a communication setting routine,
3 is a circuit block diagram of an in-vehicle electronic control device to which an electronic device is connected to the outside, and FIG. 4 is a circuit block diagram of the SCI and communication line switching circuit.

In FIG. 3, reference numeral 1 is mounted on a vehicle such as an automobile and is used for power train control such as an engine and an automatic transmission, body control such as an air conditioner and various information systems, vehicle control such as suspension and auto cruise. The electronic control unit according to the present embodiment, and in the present embodiment, an engine control unit (EC
U).

The ECU 1 is a CPU which is a main arithmetic unit.
2. ROM3 in which fixed data such as engine control programs and various maps are stored, RAM4 in which data after processing output signals of various sensors and switches and data processed by calculation are stored, various sensors and switches Input interface 5 for inputting signals from various types, an output interface 6 for outputting control signals for various actuators, etc., and a serial communication interface (SCI) as communication means for performing serial communication with the externally connected electronic device 100. ) 7 is mainly composed of a microcomputer connected to each other via a system bus 8. A constant voltage circuit 8 for supplying a predetermined constant voltage to each unit, and actuators driven by signals from the output interface 6 Drive circuit 6a and electronic device 10 connected to the outside Depending on whether the data communication method from the above is full-duplex communication or half-duplex communication, the data transmission system for communication is selectively switched between two systems in which reception and transmission are independent of each other and one system for both reception and transmission. Peripheral circuits such as a communication line switching circuit 7a as a system switching means are built in.

As the data input through the input interface 5, the cooling water temperature signal detected by the cooling water temperature sensor 10, the lean / rich signal of the air-fuel ratio detected by the O2 sensor 11, and the intake air amount sensor 12 are measured. Intake air amount signal, air conditioner SW (switch) 13 ON / OF
F signal, vehicle speed signal detected by vehicle speed sensor 14, ON / OFF signal of idle SW 15, throttle opening sensor 1
Throttle opening signal detected in 6, neutral SW1
7 is an ON / OFF signal, an engine speed signal detected by the engine speed sensor 18 and the like. Each input data of these is processed by the CPU 2 and temporarily stored in the RAM 4 to be used for calculation of the control amount. . That is, C
The PU 2 calculates various control amounts such as the fuel injection pulse width and the ignition timing based on each data stored in the RAM 4, and outputs a control signal corresponding to the control amount from the output interface 6 to the drive circuit 6a. To a predetermined timing.

The drive circuit 6a includes a canister controller 19 for controlling the canister purge amount, an EGR actuator 20 for controlling the EGR amount, an idle control actuator 21 for controlling the idle speed, and an ignition for applying a high voltage to the ignition plug. A coil 22, an injector 23 for injecting fuel, and the like are connected and driven by a control signal from the output interface 6 to control the engine to an optimum state for each operating region.

Further, in the drive circuit 6a, when an abnormality in the system is detected by the self-diagnosis function, the R
A self-diagnosis lamp 24 is connected to display a trouble code corresponding to the faulty part read from the OM 3 by, for example, appropriately lighting a plurality of lamps or blinking a predetermined number of times.

It should be noted that a part of the RAM 4 is a backup RAM that retains data by being supplied with power from the battery VB through the constant voltage circuit 9 even after the system is powered off. Learning value by control,
A trouble code or the like corresponding to the failed part detected by the self-diagnosis function is stored.

An external electronic device 100 can be connected to the ECU 1 via an external connection connector 2a, and data transmission to the external electronic device 100 via the output interface 6 and the above-mentioned are possible. External electronic device 10 by serial communication via the communication line switching circuit 7a
Data can be exchanged with 0.

As the electronic device 100 connected to the outside, a failure diagnosis device for reading data from a vehicle-mounted electronic control device to perform a failure diagnosis, or a vehicle-mounted electronic control device as a target, creating various control programs, data setting, and debugging. There is a development support device that performs such things as an electronic device for completion inspection, and while the communication method that is often used for failure diagnosis devices is the half-duplex communication method that conforms to international standards, the development support device and the completion In the inspection electronic device, it is desirable to adopt a general full-duplex communication method in consideration of a large amount of data to be handled and a data transmission rate.

Therefore, the ECU 1 determines whether the communication method of the external electronic device 100 is full-duplex communication or half-duplex communication based on the data from the electronic device 100 connected to the outside, and switches the communication line. Circuit 7a allows full duplex communication,
It has a function as a communication setting means capable of supporting any communication method of half-duplex communication.

The SCI 7 to which the communication line switching circuit 7a is connected is a communication interface having a module structure in which a receiving section and a transmitting section are independent, and as shown in FIG. 4, a receive data register for storing received data. (RD
R) 25, a transmit data register (TDR) 26 for storing transmission data, a transmission / reception controller 27 for controlling transmission / reception, a baud rate generator 28 for setting a communication baud rate, etc. are connected to each other via a module bus 29, and the RDR 25 A receive shift register (RSR) 30 for receiving data from the communication line switching circuit 7a and transferring the data to the RDR 25 upon completion of reception of 1-byte data is connected to the TDR 26 and the communication to the TDR 26. Transmit the data to the line switching circuit 7a, and when the 1-byte data transmission is completed, the data is transferred from the TDR 26.
The shift register TSR31 is connected, and the module bus 29 is connected to the system bus 8 via the bus interface 32.

Further, the transmission / reception controller 27 includes
Serial status register (SSR) that indicates the operation status such as write enable of transmission data, completion of data reception, occurrence of reception error, permission / prohibition of transmission operation or reception operation, permission / prohibition of transmission completion interrupt request TX1, Enable / disable reception completion interrupt request RX1, reception error interrupt request ER1
Serial control register (SC) for controlling operations such as enabling / disabling
R), a serial mode register (SMR) for selecting a start-stop synchronization type or a clock synchronization type, setting a transfer format such as parity generation and a parity check in the start-stop synchronization type, and the baud rate generator 28. Selects the system clocks Φ, Φ / 4, Φ / 16, Φ / 64 or the external clock SCK in combination with the SMR to set the bit rate (bit / bit).
s) bit rate register (BR
R) is provided.

The communication line switching circuit 7a includes one transmission buffer 3 connected to the external electronic device 100.
5 is provided with a reception buffer 36 for full-duplex communication and a reception buffer 37 for half-duplex communication, the connection of which is switched according to the communication system of the external electronic device 100, and a high-level signal. Is turned on, and analog switches 38 and 39 for switching the reception buffers 36 and 37 between full-duplex communication and half-duplex communication, and an inverter that inverts the analog switch control signal output from the output port Po of the output interface 6. 40 and 40.

The output terminal of the reception buffer 36 for full-duplex communication is connected to the RSR 30 of the SCI7 through an analog switch 38 as a second switch means.
The output terminal of the reception buffer 37 for half-duplex communication is connected to the input port PI of the input interface 5, and the analog switch 3 as the first switch means is provided.
It is connected to the RSR 30 via 9.

The input terminal of the reception buffer 37 for half-duplex communication and the output terminal of the transmission buffer 35 are connected to each other, and the input terminal of the transmission buffer 35 is T of the SCI7.
It is connected to SR31. Further, the control input terminal of the analog switch 39 is connected to the output port PO of the output interface 6, and the control input terminal of the analog switch 38 is connected to the output port PO of the output interface 6 via the inverter 40. .

That is, when the control signal from the output port P0 of the output interface 6 is at low level, the analog switch 39 to which this low-level control signal is input is turned off, and the control signal inverted by the inverter 40 is input. Since the analog switch 38 for ON is turned on, the reception buffer 37 for half-duplex communication is disconnected, the reception buffer 36 for full-duplex communication is connected to the RSR30 of SCI7, and the electronic device via the transmission buffer 35 from the TSR31 of SCI7. A two-wire system in which a first data transmission system (transmission system) reaching 100 and a second data transmission system (reception system) reaching the RSR 30 of SCI7 from the electronic device 100 via the reception buffer 36 are independent from each other. Duplex communication is possible.

On the other hand, when the control signal from the output port P0 of the output interface 6 is at high level, the analog switch 39 to which this high-level control signal is input is turned on, and the control signal inverted by the inverter 40 is input. Since the analog switch 38 for OFF is turned off, the reception buffer 36 for full-duplex communication is disconnected, the reception buffer 37 for half-duplex communication is connected to the RSR30 of SCI7, and the TSR31 of SCI7 is transmitted via the transmission buffer 35. A line in which a first data transmission system (transmission system) reaching the device 100 and a second data transmission system (reception system) reaching the RSR 30 of the SCI 7 from the electronic device 100 via the reception buffer 37 are combined in one system Half-duplex communication is possible.

The setting process of serial communication with the external electronic control unit 100 in the ECU 1 will be described below with reference to the flowchart of FIG.

First, when the power of the system is turned on, the system is initialized in step S101.
When the registers and the like inside the SCI7 are initially set in S102, the process proceeds to step S103, and the RSR30 of the SCI7 is activated so that data can be received from the external electronic device 100.

Next, in step S104, the output port P0 of the output interface 6 is set to low level, the analog switch 39 of the communication line switching circuit 7a is turned off and the analog switch 38 is turned on, and the reception buffer for full-duplex communication is obtained. When 36 is connected to the RSR30 of SCI7 and the reception buffer 37 for half-duplex communication is separated from the RSR30 of SCI7, it is checked in step S105 whether or not there is received data in the RDR25 of SCI7.

As a result, the reception buffer 3 for full-duplex communication
When data is input from the external electronic device 100 via 6 and the received data is stored in the RDR 25 of SCI7, the process jumps from step S105 to step S109, while there is no received data in the RDR 25 in step S105. Sometimes, the above steps S105 to S1
The flow advances to 06 to read the data from the reception buffer 37 for half-duplex communication via the input port PI of the input interface 5, and then the flow advances to step S107.

In step S107, it is checked whether or not the data read in step S106 is the half-duplex communication initialization procedure. This initialization procedure is, for example, address designation for identifying the ECU 1 from the external electronic device 100 side and waiting for a response, and for full-duplex communication in which data is transmitted at high speed, a code of 1 byte is used. 5 baud (= 5 bit
/ S) is sent at a low speed. Therefore, when the initialization procedure of 5 baud is not sent from the external electronic device 100, that is, when neither full-duplex communication nor half-duplex communication is performed, the process jumps to step S111, When initialized by 5 baud, the process proceeds to step S108.

In step S108, the output interface 6
Output port P0 is set to a high level, the analog switch 39 of the communication line switching circuit 7a is turned on and the analog switch 38 is turned off, and the reception buffer 3 for full-duplex communication is
6 is separated from the RSR30 of SCI7 and the reception buffer 37 for half-duplex communication is connected to the RSR30 of SCI7,
It proceeds to step S109.

Then, the above steps S108 to S1
When the process proceeds to 09, or when the process jumps from step S105 to step S109, at step S109, SC
Activates I7 TSR31. As a result, there is received data in the RDR 25 in step S105,
When jumping from S105 to step S109, the reception buffer 36 for full-duplex communication is connected to the RSR 30, and data can be transmitted from the TSR 31 to the transmission buffer 35 to enter the full-duplex communication mode. When the process proceeds to step S109 after passing through, the reception buffer 37 for half-duplex communication is connected to the RSR 30, and data can be transmitted from the TSR 31 to the transmission buffer 35, and the half-duplex communication mode is set.

Then, the above steps S109 to S1
At step 10, the communication active flag F indicating that communication with the external electronic device 100 is enabled is set (F
← 1), after executing the main control routine in step S111, the process proceeds to step S112 to refer to the communication active flag F.

When F = 1 and the communicable state continues, the process returns from step S112 to step S111 to repeat the execution of the main control routine, and when F = 0 and the communication is once completed. , The process returns from step S112 to step S105 to reset the communication.

As a result, whether the external electronic device 100 connected to the ECU 1 is a full-duplex communication system or a half-duplex communication system, the electronic device 100 is automatically operated.
The communication method will be carried out by the communication method of 1), and the development method will be completed by changing the communication method of the ECU 1 to the half-duplex communication method, with an emphasis on the communication connectivity with the failure diagnosis device of the half-duplex communication method in the market. Communication capacity will not be insufficient during inspection. On the contrary, when the communication system of the ECU 1 is set to the full-duplex communication system with emphasis on the communication capability at the time of development and completion inspection, no trouble occurs in communication with the failure diagnosis device in the market.

[0040]

As described above, according to the present invention, whether the electronic device connected to the outside is the full-duplex communication system or the half-duplex communication system, the external device is automatically connected to the external device. It is possible to communicate with the communication method of electronic devices, prevent shortage of communication capacity due to fixing to the half-duplex communication method, and do not cause connection problems due to fixing to the full-duplex communication method. In addition, it is possible to obtain excellent effects such as flexible support according to the external electronic device.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram of the present invention.

FIG. 2 is a flowchart of a communication setting routine.

FIG. 3 is a circuit block diagram of an in-vehicle electronic control device in which an electronic device is connected to the outside.

FIG. 4 is a circuit block diagram of an SCI and communication line switching circuit.

[Explanation of symbols]

 1 ... ECU (electronic control unit, communication setting means) 7 ... SCI (communication means) 7a ... communication line switching circuit (transmission system switching means)

Claims (4)

[Claims] 1. An electronic control device for a vehicle, which is mounted on a vehicle and is capable of exchanging data by serial communication with an electronic device connected to the outside, and a receiving unit for storing data from the electronic device, and the receiving unit. A communication unit having a transmission unit that stores data to be independently transmitted to the electronic device; a data transmission system from the electronic device to the reception unit; and a data transmission system from the transmission unit to the electronic device, When a transmission system switching means for selectively switching between two systems independent of each other and one system for both reception and transmission, and the electronic device are connected, the communication system of the electronic device is based on data from the electronic device. If the full-duplex communication method or the half-duplex communication method is discriminated, and if it is discriminated that the full-duplex communication method, the data transmission system is set to two independent systems by the transmission system switching means. In this state, the communication means enables bidirectional communication with the electronic device, and when the half-duplex communication method is determined, the transmission system switching means causes the data transmission system to be a single system for both reception and transmission. 2. A vehicle electronic control unit comprising: a communication setting unit that enables bidirectional communication by the communication unit. 2. The transmission system switching means connects the transmission section to a first data transmission system, and the reception section is connected to the first switching means which is turned on and off by the communication setting means. And a second data transmission system, which is a system different from the first data transmission system, via a second switch means that is turned on and off by the communication setting means. Item 2. The vehicle electronic control unit according to Item 1. 3. The communication setting means determines all communication methods of the electronic device based on the data stored in the receiving section in a state where the data transmission system is set to two independent systems by the transmission system switching means. When it is determined that the communication system is not the duplex communication system and the system is not the full-duplex communication system, the data transmission system is set to one system for both reception and transmission by the transmission system switching means and the reception is performed from the electronic device. 2. The vehicle electronic control device according to claim 1, wherein it is determined whether or not the communication system of the electronic device is a half-duplex communication system based on the data read without passing through the section. 4. The vehicle electronic control device according to claim 2, wherein the first switch means is a first analog switch, and the second switch means is a second analog switch. .