JP3246302B2 - Automotive electronic control unit - Google Patents

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 a vehicle, and more particularly, to an electronic control unit for a vehicle that performs data communication by serial communication.

[0002]

2. Description of the Related Art FIG. 1 is a block diagram showing a configuration of a serial communication system of an electronic control unit for a vehicle, and FIG.
It shows the configuration of an address table set in a program.

FIG. 1 shows an electronic control unit (Elect) for a vehicle.
oronic ControlUnit: ECU
In (1), an arbitrary address input from an external monitor is received by the receiving unit 6 of the serial communication interface, and the contents of the memory (RAM 5 and ROM 4) defined at the address are serially transmitted via the control unit 3. The use of the serial communication protocol 1 to be output to the external monitor using the transmission unit 7 of the communication interface monitor and the reception unit 6 of the serial communication interface is stopped, and the address [ 1] to [n] are sequentially output using the transmission unit 7 of the serial communication interface.

[0004] Among such serial communication protocols, serial communication protocol 1 is mainly used for debugging software and checking functions when developing an ECU, and serial communication protocol 2 is used after software is installed during mass production. It is mainly used for confirmation of hardware, checking of hardware, replacement of software, and updating.

[0005] To switch the communication protocol, RO
1-byte data in M4 is used as a switch (hereinafter referred to as a data switch). For example, when developing an ECU, communication with an external monitor is performed using protocol 1, and during mass production of the ECU, protocol 2 is used. Then, the input / output signal values, ROM data, and the like processed in the CPU 2 are transmitted to the automatic inspection device that checks the ECU hardware on the production line.

[0006]

However, usually,
At the time of mass production of the ECU, the inspection is performed using the mask ROM 4. Therefore, the data switch cannot be changed. When analyzing the mass production ECU, only the automatic inspection device can use the ECU. ROs other than the memory contents from the set address [1] to address [n]
The contents of M4 and RAM 5 cannot be accessed from outside.

In a conventional electronic control unit for a vehicle, during mass production, it is impossible to externally access memory contents other than the memory contents of a pre-designated address.
The memory contents at the specified address could also be accessed only from the automatic inspection device.

The present invention solves this problem. Even when an automatic inspection device is accessed during mass production, the reception status from a monitor is monitored by software, and the serial communication protocol is switched according to the presence or absence of reception data. It is another object of the present invention to provide an electronic control unit for a vehicle which can automatically switch and execute serial communication of two different specifications even when a mask ROM is used.

[0009]

To achieve the above object, according to an aspect of the present invention includes a central control unit for controlling each part of an automobile, and software means for driving the central control unit,
Storage means for storing data related to the control operation of the a RAM and a mask ROM software means and said central controller, a serial communication means for performing serial communication with an external device, the storage means and controls the serial communication unit the electronic control unit for a motor vehicle having an overflow counter means for using said software means and said data stored in a plurality of serial communication protocol means for outputting to the outside, the count in the central control device, the plurality of serial communication Protocol means from outside
Address to be input via the serial communication means.
Therefore, the contents of the storage means at the corresponding address are read.
Outgoing serial communication protocol means, and
In accordance with the order of the addresses stored in the storage means,
Second serial communication protocol for reading the contents of storage means
Means, and the software means is provided from an external device.
Determining means for determining the presence or absence of the input of the address of the user and said determination
The first serial communication protocol according to the determination result of the means.
Col means or said second serial communication protocol means
And a protocol setting means for setting any one of the following.

According to the present invention, the electronic control unit for a vehicle can automatically select a function suitable for the purpose from among a plurality of functions of the serial communication means.

Here, the plurality of serial communication protocol means includes a first serial communication protocol means for reading out the contents of the storage means at a corresponding address according to an address inputted from the outside via the serial communication means, The second serial communication protocol means reads out the contents of the storage means in the order of addresses stored in the storage means.

According to the present invention, first serial communication protocol means having a function suitable for development for reading memory contents in accordance with an externally designated address,
It is possible to automatically select any one of the second serial communication protocol means having a function required at the time of mass production for sequentially reading out preset memory blocks.

Further, the serial communication protocol selecting means selects the first or second serial communication protocol means by an interrupt input to the serial communication means and an overflow interrupt generated by the overflow counting means. Features.

According to the present invention, the first serial communication protocol is automatically provided when an address is externally input via the serial communication means within a predetermined time after the power is input, without requiring any special operation. The means is selected, otherwise the second serial communication protocol means is automatically selected, eliminating the need for an operation for selection and simplifying handling.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The first aspect of the present invention is a central control device for controlling each part of an automobile, software means for driving the central control device, and control of the software means and the central control device. Storage means for storing data relating to operation, serial communication means for serially communicating the software means and the data stored in the storage means to the outside, a plurality of serial communication protocol means for controlling the serial communication means, An electronic control unit for a vehicle having an overflow counting unit used for counting by a central control unit, comprising a serial communication protocol selecting unit for automatically selecting the plurality of serial communication protocol units. Depending on the situation, even during the inspection using the program stored in the mask ROM It is possible to automatically switch the communication of the serial communication of different specifications.

According to a second aspect of the present invention, the plurality of serial communication protocol units read out the contents of the storage unit at a corresponding address in accordance with an address input from the outside via the serial communication unit. A serial communication protocol means, and a second serial communication protocol means for reading out the contents of the storage means in accordance with the order of addresses previously stored in the storage means, wherein a mask ROM is used. Even during the inspection, a communication method suitable for development and a communication method suitable for mass production can be automatically selected.

Further, the invention according to claim 3 of the present invention is characterized in that the serial communication protocol selecting means uses the first or second interrupt by the interrupt input to the serial communication means and the overflow interrupt generated by the overflow counting means. The serial communication protocol means is selected, and if an address is externally input via the serial communication means before the overflow counting means generates an overflow interrupt, the first automatically occurs.
The serial communication protocol means is selected, and the operation is simple without any special procedure.

Hereinafter, an electronic control unit for a vehicle according to the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 3, 4 and 5 show flowcharts of an embodiment of the serial communication protocol automatic switching process according to the present invention.

The configuration of the serial communication system of the electronic control unit (ECU) is the same as the conventional one shown in FIG.

The processing of this embodiment will be described with reference to FIGS. 3, 4, 5 and 1. When the power is supplied to the CPU 3, the built-in 16-bit free running counter 8 starts counting up, and at the same time, the initial processing of FIG. 3 starts.

In this initial processing, first, the serial communication protocol is set to protocol 1 (step 1).
0), a reception interrupt is permitted to wait for an address input from an external monitor or the like (step 11).

Next, a communication protocol selection flag FM
ONITOR is set to 1 (step 12), and background processing is started (step 13).

In this state, when an address input from an external monitor or the like is received by the serial communication interface receiver 6 (step 14), a reception interrupt process is executed (step 15), and thereafter, the process returns to the background process again.

In the reception interruption processing, a communication protocol selection flag F MONITOR as shown in FIG. 4 is cleared to 0 (step 20).

On the other hand, when the 16-bit free-running counter 8 overflows for the first time, a time overflow process shown in FIG. 5 is executed by the overflow signal.

In this process, first, it is determined by referring to F MONITOR whether or not an address has been input from an external monitor or the like before the first overflow (step 30). If F MONITOR is 0, it is determined that an address has been input from an external monitor or the like, and the subsequent processing is passed to maintain the communication method as set in the initial processing of protocol 1.

Conversely, if F MONITOR is 1,
It is determined that there is no address input from an external monitor or the like. In this case, it is determined that the communication method should be protocol 2, and the communication protocol selection flag F MO
NITOR is cleared to 0 (step 31). Next, the serial communication protocol is set to protocol 2 (step 32), and the reception interrupt is prohibited (step 33).
Therefore, after this, address input from an external monitor or the like is not accepted.

In the overflow process of the 16-bit free-running counter 8 from the next time on, F MONITOR has already been set to 0 regardless of the communication protocol, so that the communication protocol setting is not changed.
The current communication protocol is kept as it is.

According to the above-described method, the vehicle electronic control unit (ECU) of the present invention sets the communication protocol to the communication protocol 1 at the time of initial setting of the CPU, permits reception and reception interruption, and turns on the power. Thereafter, when the 16-bit free running counter 8 overflows for the first time, for example, the count 1 bit becomes 3.2 μm.
In the case of s, in the interrupt processing that occurs after 209 ms, the communication protocol 1 is held if data has been received by the serial communication interface receiving unit 6 until then, and if no data has been received, the communication protocol is held. 2
To stop reception at the serial communication interface receiver 6 and prohibit reception interrupt.

Therefore, the mask RO is determined based on whether or not data has been received by the serial communication interface receiver 6.
Even when M is used, a communication protocol is automatically selected, and processing can be performed by a simple operation without requiring a special procedure.

[0032]

As described above, the present invention provides an external device
Judgment means to judge the presence or absence of an address input from
A first serial communication protocol according to the determination result of the means;
Means or said second serial communication protocol means.
Serial having protocol setting means for setting any
Serial communication protocol using the
Since the switching of colors is performed , even when a mask ROM is used, it is input externally via the serial communication means.
According to the input address
First serial communication protocol for reading the contents of the storage means
And an address previously stored in the storage means.
A second system for reading the contents of the storage means in order.
It is possible to provide an electronic control unit for a vehicle which can automatically select and use a real communication protocol means .

[Brief description of the drawings]

FIG. 1 is a block diagram of a serial communication system of an electronic control unit to which the present invention is applied.

FIG. 2 is a configuration diagram of an address table set in a program;

FIG. 3 is a flowchart of an initial processing program according to an embodiment of the present invention.

FIG. 4 is a flowchart of a reception interrupt processing program according to an embodiment of the present invention.

FIG. 5 is a flowchart of a 16-bit free-running counter overflow interrupt processing program according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electronic control apparatus main body 2 CPU 3 Control part 4 ROM or mask ROM 5 RAM 6 Serial communication interface receiving part 7 Serial communication interface transmitting part 8 16-bit free running counter

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04L 29/06

Claims (2)

(57) [Claims] 1. A central control device for controlling each part of an automobile, software means for driving the central control device,
Storage means for storing data related to the control operation of the a RAM and a mask ROM software means and said central controller, a serial communication means for performing serial communication with an external device, the storage means and controls the serial communication unit the electronic control unit for a motor vehicle having an overflow counter means for using said software means and said data stored in a plurality of serial communication protocol means for outputting to the outside, the count in the central control device, the plurality of serial communication Protocol means from outside
Address to be input via the serial communication means.
Therefore, the contents of the storage means at the corresponding address are read.
Outgoing serial communication protocol means, and
In accordance with the order of the addresses stored in the storage means,
Second serial communication protocol for reading the contents of storage means
Means, and the software means is provided from an external device.
Determining means for determining the presence or absence of the input of the address of the user and said determination
The first serial communication protocol according to the determination result of the means.
Col means or said second serial communication protocol means
An electronic control unit for a vehicle , comprising: a serial communication protocol selecting unit having a protocol setting unit that sets the protocol to one of the following . 2. The serial communication protocol selecting means according to claim 1, wherein
An interrupt input to the serial communication means;
-Overflow interrupt generated by overflow counting means
The first or second serial communication protocol
2. The self-selecting means according to claim 1, wherein the selecting means selects
Electronic control unit for moving vehicles.