JP2007058659A - Method for testing hardware of on-vehicle device and method for writing software for product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce costs by making it unnecessary to load any ROM with a large capacity on a microcomputer, and to promote miniaturization by making it unnecessary to provide any terminal for a test mode. <P>SOLUTION: Software for a test mode is written in a flash ROM 32b of a microcomputer 31 by using CAN communication by a flash ROM/EEPROM writer 5 connected to a connector 33 for external connection. Then, the microcomputer 31 executes a hardware test based on the software for a test mode written in the flash ROM 32b. When the hardware test ends, a connector 33 for external connection is connected to a flash ROM/EEPROM writer 5 again. Then, the software for a product is transferred to the microcomputer 31 and written in an EEPROM 32 by using CAN communication through the connector 33 for external connection. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an in-vehicle device hardware test method and a product software writing method, and more particularly to an in-vehicle device hardware test method and a product software writing method that effectively use an in-vehicle LAN interface.

  In general, in-vehicle devices such as a meter device, a hardware test of the in-vehicle device is executed before shipment and product software is written. FIG. 5 is a block diagram showing a schematic configuration on a meter board included in a conventional meter device. FIG. 6 is a flowchart showing a conventional test and writing process.

  As shown in FIG. 5, the meter board 90 is equipped with a microcomputer 91, an EEPROM (Electrically Erasable and Programmable ROM) 92, an external connection connector 93, an EEPROM writing terminal 94, and a test mode terminal 95. . The microcomputer 91 includes a mask ROM 91a, a CPU Central Processing Unit (not shown) and a RAM (Random Access Memory), and controls the meter device including the meter board 90. In the EEPROM 92, product software is stored.

  An in-vehicle LAN or an external device can be connected to the external connection connector 93, and the EEPROM writer 9 is connected to the EEPROM writing terminal 94. The test mode terminal 95 is for setting the microcomputer 91 to the test mode by dropping it to the ground.

  At the time of hardware test and product software writing, as shown in FIG. 6, the EEPROM writing terminal 94 is connected to the EEPROM writer 9 in step S901. Next, in step S902, the product software is written into the EEPROM 92 via the EEPROM writing terminal 94. In step S903, the writing of the product software is finished.

  Next, in step S904, the microcomputer 91 is set to the test mode by connecting the test mode terminal 95 on the meter substrate 90 to the ground. In step S905, the microcomputer 91 executes a hardware test based on the test mode software stored in advance in the mask ROM 91a. In step S906, the hardware test ends. In the hardware test, LCD (Liquid Crystal Display) segment display, pointer operation, indicator operation check, and the like are performed.

Although there is no prior art document directly related to the invention of this application, a general integrated circuit self-test method is disclosed in, for example, the following patent documents.
JP-T-2002-521474

  However, in the test and writing method according to the conventional configuration and process described above, the EEPROM board 94 and the test mode terminal 95 are required on the meter substrate 90, which is an obstacle to miniaturization. Since the ROM mounted on the microcomputer 91 is the mask ROM 91a, it is necessary to store test mode software on the ROM 91a in advance. Accordingly, since it is necessary to secure a storage area for the test mode software on the mask ROM 91a, a large-capacity mask ROM 91a is required, which increases the cost.

  Therefore, in view of the present situation described above, the present invention provides an in-vehicle device that can reduce the cost by eliminating the need for mounting a large-capacity ROM in the microcomputer, and can promote downsizing without the need for a test mode terminal. It is an object to provide a hardware test method and a software writing method for products.

  A hardware test method for an in-vehicle device according to claim 1, which has been made to solve the above-described problem, includes a microcomputer for mounting an external connection connector connectable to an in-vehicle LAN and a writing device, an in-vehicle LAN interface, and a flash ROM. And an EEPROM into which product software is written, the method of executing a hardware test of an in-vehicle device, wherein the writing device connected to the external connector via the in-vehicle LAN interface The software relating to the hardware test is written in the flash ROM, and the hardware test is executed using the written software.

  According to the first aspect of the present invention, software related to the hardware test is written into the flash ROM via the in-vehicle LAN interface by the writing device connected to the external connection connector, and the written software is used. The hardware test is executed.

  The method for writing software for a product of an in-vehicle device according to claim 2 for solving the above-mentioned problem is connected to the external connection connector after execution of the hardware test by the hardware test method according to claim 1. The product software is written into the EEPROM by the written writing device.

  According to the second aspect of the present invention, the product software is written in the EEPROM using the external connection connector.

  According to the first aspect of the present invention, the software relating to the hardware test is written into the flash ROM via the in-vehicle LAN interface by the writing device connected to the external connector, and the hardware is written using the written software. Run the wear test. Therefore, it is not necessary to previously store software relating to the hardware test in the ROM mounted on the microcomputer, so that it is not necessary to mount a large-capacity ROM on the microcomputer, and the cost can be reduced. In addition, since the test mode terminal is not required, downsizing of the apparatus is promoted.

  According to the second aspect of the invention, the product software is written in the EEPROM using the external connection connector. Therefore, an EEPROM writing terminal is not required, and further cost reduction and downsizing of the apparatus can be promoted.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, the configuration of an in-vehicle device that is a premise of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram for explaining CAN as an in-vehicle LAN. FIG. 2 is a block diagram showing a meter ECU as an in-vehicle device connected to the in-vehicle LAN.

  As shown in FIG. 1, a CAN (Controller Area Network) bus 4 for connecting an engine ECU (Electronic Control Unit) 1, a door ECU 2, a meter ECU 3 and the like is laid in the vehicle. The CAN bus 4 communicates and connects in-vehicle devices such as the engine ECU 1, the door ECU 2, and the meter ECU 3 using CAN, which is frequently used as an in-vehicle LAN, from the viewpoint of cost and versatility.

  The engine ECU 1, the door ECU 2, and the meter ECU 3 are vehicle-mounted devices that perform control related to the engine, the door, and the meter, respectively. Of course, another type of ECU (not shown) is also connected to the CAN bus 4 in the vehicle.

  As shown in FIG. 2, for example, the meter board 30 corresponding to the meter ECU 3 includes a microcomputer 31, an EEPROM 32, and an external connection connector 33, and the external connection connector 33 is connected to the CAN bus connector 43. It is connected to the CAN bus 4. In the present invention, an in-vehicle device configured on the premise of such an in-vehicle communication system is effectively used for hardware testing and product software writing.

  FIG. 3 is a block diagram showing a schematic configuration on the meter board included in the in-vehicle device according to the embodiment of the present invention. FIG. 4 is a flowchart illustrating a test and writing process according to an embodiment of the present invention.

  As shown in FIG. 3, a microcomputer 31, an EEPROM 32, and an external connection connector 33 are mounted on the meter board 30. A flash ROM / EEPROM writer 5 (corresponding to the writing device in the claims) can be connected to the meter board 30.

  The microcomputer 31 includes a CAN I / F (interface) 32a and a flash ROM 32b, and a CPU and RAM (not shown), and controls the meter device including the meter board 30. The CAN I / F 32a is an interface for communicating with another device (ECU) using a CAN as an in-vehicle LAN. The flash ROM 32b is a kind of memory that can freely erase and write data and whose contents are not lost even when the power is turned off.

  The EEPROM 32 is a ROM in which data can be rewritten and erased in byte units later by electrical operation. Here, the EEPROM 32 is connected to the microcomputer 31 to write product software. The external connection connector 33 is an internal connection to the microcomputer 31, and can be externally connected to the CAN bus connector 43 as shown in FIG. 2, for example, the flash ROM / EEPROM writer 5, or the like.

  Further, the flash ROM / EEPROM writer 5 is internally connected to the external connection connector 33, and is a device for writing test mode software (corresponding to the software related to the hardware test in claims) and product software. It is.

  On the premise of such a configuration, at the time of hardware test and product software writing, as shown in FIG. 4, in step S1, the flash ROM / EEPROM writer 5 connected to the external connector 33 is used. The test mode software is written into the flash ROM 32b of the microcomputer 31 using CAN communication. When this writing is completed, the flash ROM / EEPROM writer 5 is once separated from the external connection connector 33 in order to perform a hardware test smoothly.

  Next, in step S2, the microcomputer 31 executes a hardware test based on the test mode software written in the flash ROM 32b. In step S3, the hardware test ends. In the hardware test, LCD segment display, pointer operation, indicator operation check, and the like are performed. By the above steps S1 to S3, there is no need to mount a test mode terminal on the meter board as in the prior art, and the ROM mounted on the microcomputer can be small in capacity.

  When the hardware test is completed, the external connection connector 33 is connected to the flash ROM / EEPROM writer 5 again in step S4. In step S5, the product software is transferred to the microcomputer 31 via the external connection connector 33 and written in the EEPROM 32. In step S6, the writing of the product software is completed. Note that CAN communication is also used for writing here.

  As described above, according to the embodiment of the present invention, it is not necessary to store test mode software in the ROM mounted on the microcomputer in advance, so that it is not necessary to mount a large-capacity ROM on the microcomputer. As a result, the cost can be reduced. If the capacity of the ROM mounted on the microcomputer is equivalent to the conventional capacity, the capacity that can be freely used increases, so that it is possible to deal with more variations and the effect of reducing the product number can be obtained.

  Further, since a test mode terminal and an EEPROM writing terminal are not required as in the prior art, further cost reduction and downsizing of the apparatus can be promoted. Moreover, the board | substrate arrangement | positioning at the time of board | substrate separation becomes easy, and the freedom degree of the design design of a meter becomes large.

  In the above embodiment, CAN is exemplified as the in-vehicle LAN, but the in-vehicle LAN may be another type of protocol such as SWS or MUT.

It is a figure for demonstrating CAN as in-vehicle LAN. It is a block diagram which shows meter ECU as an in-vehicle apparatus connected to in-vehicle LAN. It is a block diagram which shows schematic structure on the meter board | substrate contained in the vehicle-mounted apparatus based on one Embodiment of this invention. 3 is a flowchart illustrating a test and writing process according to an embodiment of the present invention. It is a block diagram which shows schematic structure on the meter board | substrate contained in the conventional meter apparatus. It is a flowchart which shows the conventional test and writing process.

Explanation of symbols

5 Flash ROM / EEPROM writer (writing device)
30 Meter board 31 Microcomputer 32 EEPROM
32a CAN interface (in-vehicle LAN interface)
32b Flash ROM
33 External connector

Claims (2)

An external connection connector connectable to the in-vehicle LAN and the writing device;
A microcomputer equipped with an in-vehicle LAN interface and a flash ROM;
EEPROM where product software is written,
A method for performing a hardware test of an in-vehicle device having
Write the software related to the hardware test to the flash ROM via the in-vehicle LAN interface by the writing device connected to the external connection connector,
The hardware test is executed using the written software.
A hardware test method for an in-vehicle device. After execution of the hardware test by the hardware test method according to claim 1,
The product software is written in the EEPROM by a writing device connected to the external connection connector.
A method for writing software for a product of an in-vehicle device.

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