JP2003076574A - Method for inspecting electronic unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for inspecting an electronic unit 1 in which no control program for inspection is erroneously executed in cases except the inspection. SOLUTION: In this method for inspecting the electronic unit, a terminal T11 for connecting external memory and a switching signal input terminal T10 to the electronic unit 1 is provided, a function that executes a control program for inspection in an external memory 43 connected with the terminal T11 for connecting the external memory is provided to its microcomputer 3 based on a switching signal to be inputted via the switching signal input terminal T10, the external memory 43 is connected with the electronic unit 1 only in the case of the inspection, the microcomputer 3 is made to read and execute the control program for inspection in the external memory 43 based on the switching signal and no control program for inspection is left in the electronic unit 1 by detaching the external memory 43 from the electronic unit 1 after termination of the inspection.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an input signal input from a predetermined input terminal in a normal mode according to a normal control program and in a test mode according to a test control program. The present invention relates to a method for inspecting an electronic unit that outputs a predetermined output signal from a predetermined output terminal. 2. Description of the Related Art FIG. 3 is a view showing an example of the configuration of an electronic unit and an inspection machine in a conventional electronic unit inspection method, and FIG. 4 employs a conventional electronic unit inspection method. FIG. 9 is a diagram for explaining a malfunction of the electronic unit that may occur in such a case. An electronic unit of this type is mounted on a vehicle, for example, and is connected to various on-vehicle switches and various on-vehicle sensors, and is also connected to loads such as a driving motor and a lamp. (SW signal, sensor signal, etc.) to drive those loads,
It is connected to an in-vehicle LAN to perform data communication with other in-vehicle devices. Such an electronic unit 101 generally has a plurality of input terminals (a power supply input terminal T1, a communication signal input / output terminal T2, and one or more (two in the figure) SW signals) as shown in FIG. Input terminals T3, T4, one or more (two in the figure) sensor signal input terminals T5, T6) and a plurality of output terminals (earth output terminal T7, one or more for outputting a drive signal for driving a load (FIG. Two) drive signal output terminals T8, T9), microcomputer 103, power supply circuit 5, communication circuit 7, SW input circuit 9, AD input circuit 11,
An output circuit 13 is provided. Power input terminal T1
Is connected to the microcomputer 103 via the power supply circuit 5, and the communication signal input / output terminal T2 is connected to the microcomputer 10 via the communication circuit 7.
3, the SW signal input terminals T3 and T4 are connected to the microcomputer 103 via the SW input circuit 9, the sensor signal input terminals T5 and T6 are connected to the microcomputer 103 via the AD input circuit 11, and the ground output terminal. T7 is microcomputer 1
The drive signal output terminals T 8 and T 9 are connected to the microcomputer 103 via the output circuit 13. Here, the power supply circuit 5 has a power supply input terminal T1.
The power supply current and the power supply voltage from the outside that are input to the microcomputer 103 are converted into currents and voltages at the microcomputer level and input to the microcomputer 103. The communication circuit 7 converts a communication signal from a communication partner input to the communication signal input / output terminal T2 into a microcomputer-level signal, inputs the signal to the microcomputer 103, converts a signal from the microcomputer 103 into a communication signal, and converts the communication signal into a communication signal. Input / output terminal T2
Output to the communication partner. The SW input circuit 9 converts an external SW signal input to each of the SW signal input terminals T3 and T4 into a microcomputer-level signal and inputs the signal to the microcomputer 103. The AD input circuit 11 is connected to each sensor signal input terminal T
5, the external sensor signal input to T6 is converted into a microcomputer level signal and input to the microcomputer 103. The output circuit 13 outputs a drive signal for driving each load according to each control signal from the microcomputer 103 to each drive signal output terminal T
8. Output from T9. The microcomputer 103 has an internal memory 103
a, a control program that defines the processing operation of the microcomputer 103 (ie, what output signals are output from which output terminals T2, T7 to T9 for each external signal input to each input terminal T1 to T6). And a processing that defines what processing operation is to be performed on an external communication signal input to the communication signal input / output terminal T2). Is turned on and the microcomputer 103 is started, the control program is executed, the mode is set to the normal mode, and operation is performed according to the control program. In the conventional method of inspecting the electronic unit 101, the internal memory 103 a of the microcomputer 103 is further added.
In addition, a control program for inspection (a program in which the content of the control program is changed to a content suitable for inspection of the electronic unit 101, hereinafter the control program is referred to as a control program for normal use for the control program for inspection) is set, and Only when a signal (switching signal) indicating that the inspection control program should be executed is input to the microcomputer 103 via a predetermined input terminal (for example, a communication signal input / output terminal T2), the inspection control program is executed. After execution, the mode is forcibly switched to the inspection mode and set to operate according to the inspection control program. When shifting to the normal control program, the microcomputer 103 is restarted. An inspection machine 119 for inspecting the electronic unit 101 is generally configured as shown in FIG. That is, as an input / output terminal group, a plurality of output terminals (power supply output terminal S1, communication signal input / output terminal S2, 1
The above (one in the figure) SW signal output terminal S3, one or more (one in the figure) sensor signal output terminal S5) and a plurality of input terminals (earth input terminal S7, one or more (2 in the figure)
Drive signal input terminals S8, S9). Also, a control unit 121, a power supply 23 connected to the power output terminal S1 via the power switch 25, a power SW control circuit 27 for turning on and off the power switch 25 under the control of the control unit 121, and a communication signal input / output terminal S2 A communication circuit 29 connected between the control unit 121 and the SW signal output terminal S
3 and a ground switch, a SW control circuit 33 for turning on and off the simulated switch 31 under the control of the control unit 121, and a simulated sensor connected between the sensor signal output terminal S5 and ground. 35 and the control unit 1
A sensor output control circuit 37 for controlling the sensor output of the simulation sensor 35 under the control of the control circuit 21, a simulation load 39 connected between the drive signal input terminal S 8 and the power supply 23, and a drive signal input to the simulation load 39. And a detection circuit 41 for detecting. The ground input terminal S7 is grounded in the inspection machine 119. Here, the communication circuit 29 converts the communication signal from the electronic unit 101, which is input to the communication signal input / output terminal S2, into a signal at the control unit level and inputs the signal to the control unit 121. Is converted into a communication signal and output from the communication signal input / output terminal S2 to the electronic unit 101 side. The detection circuit 41 converts the drive signal input to the simulated load 39 into a signal at the control unit level and inputs the signal to the control unit 121. The control unit 121 is activated by, for example, an input operation of an operator. After the activation, first, the power switch 25 is turned on by the power SW control circuit 27, and the power of the electronic unit 101 is supplied from the power output terminal S1. Power supply from the power supply 23 to the input terminal T1 is started. Next, the communication unit 29 connects the electronic unit 1 to the communication signal input / output terminal S2.
A switching signal is output to the communication signal input / output terminal T2 on the 01 side, and the internal memory 103 is sent to the electronic unit 101.
The inspection control program in a is executed to switch the operation mode of the electronic unit 101 to the inspection mode. Then, under this inspection mode, the communication circuit 29, the SW control circuit 33, and the sensor output control circuit 37 operate the terminals S2 and S2.
Terminals T2, T on the electronic unit 101 side from S3, S5
3 and T5, while sequentially outputting a predetermined communication signal, a predetermined SW signal, and a predetermined sensor signal as test signals, and simultaneously responding to the output of each test signal, each terminal T2 on the electronic unit 101 side. Output from T8, T9, each terminal S2, S8, S9 of the inspection machine 119 side and each circuit 2
By monitoring each signal obtained through the components 9 and 41 and checking whether a predetermined output signal is obtained with respect to a predetermined test signal, it is determined whether the electronic unit 101 has a connection failure or an element failure. Is determined so that the quality of the electronic unit 101 is inspected. When the conventional electronic unit 101 is inspected by using the inspection machine 119, first, the inspection unit 11
9 are connected to corresponding terminals T1 to T3, T5, T7 to T of the electronic unit 101, respectively.
9 and start the inspection machine 119. This allows
Power from the power supply 23 is supplied from the terminal S1 on the inspection machine 119 side to the microcomputer 103 via the terminal T1 on the electronic unit 101 side and the power supply circuit 5 to start the electronic unit 101, and then from the terminal S2 on the inspection machine 119 side. The switching signal is output and input to the microcomputer 103 via the terminal T2 on the electronic unit 101 side and the communication circuit 7, whereby the electronic unit 101 activates the inspection control program in the internal memory 103a and inspects the electronic unit 101. Mode. In this inspection mode, each inspection signal is sequentially output from each of the terminals S2, S3, and S5 on the inspection machine 119 side, and is input to each of the terminals T2, T3, and T5 on the electronic unit 101 side. Terminals T2 and T8 on the electronic unit 101 side in response to the input of the
A response signal is output from each terminal S on the inspection machine 119 side.
2, the inspection machine 1 based on the response signal
19 checks the quality of the electronic unit 101. Then, after the inspection is completed, the inspection machine 119 is removed from the electronic unit 101. However, in the above-described method for inspecting the electronic unit 101, the control program for inspection is permanently set in the internal memory 103 a of the microcomputer 103 of the electronic unit 101, and is used when necessary. Only when an inspection is performed, a configuration is used in which the electronic unit 101 (microcomputer 103) is forced to execute the inspection control program by inputting the switching signal, so that the electronic unit 101 may malfunction as shown in FIG. That is, in step U1, the electronic unit 10
If the microcomputer 103 is in a normal mode (normal control state) by executing a normal control program incorporated in a vehicle, for example, in step U2, a failure occurs in the microcomputer 103 or a failure occurs in a terminal (for example, a communication signal input / output terminal T2). If no noise occurs, the process returns to step U1 and the normal mode is maintained. However, a failure that causes erroneous execution of the inspection control program occurs in the microcomputer 103, and noise or the like having the same waveform pattern as the switching signal is supplied to the terminal (for example, communication). Signal input / output terminal T2)
Is applied, the process proceeds to step U3, the inspection control program is erroneously executed, and the mode is erroneously shifted from the normal mode to the inspection mode. Then, the process proceeds to step U4, where the electronic unit 101 is required to be in the normal mode. ) May occur (normal control abnormality). An object of the present invention is to provide a method of inspecting an electronic unit in which an inspection control program is not erroneously executed except during an inspection. [0015] In order to solve the above-mentioned problems, the invention according to claim 1 is provided in accordance with a normal control program in a normal mode and a predetermined mode in a test mode in accordance with a test control program. An inspection method of an electronic unit that outputs a predetermined output signal from a predetermined output terminal in response to an input signal input from an input terminal, wherein the electronic unit includes a predetermined external memory in which the control program for inspection is set. An external memory connection terminal, which is detachably connected, and a switching signal input terminal to which a switching signal is input, and to the external memory connection terminal based on the switching signal input to the switching signal input terminal. A terminal for connecting the external memory of the electronic unit, the terminal having a function of executing the inspection control program in the connected external memory; A first step of connecting the external memory in which the inspection control program is set; and inputting the switching signal to the switching signal input terminal of the electronic unit to execute the inspection control program for the electronic unit. A second step of switching the operation mode of the electronic unit to the inspection mode, and sequentially performing an inspection signal to a predetermined input terminal of the electronic unit by the inspection machine in the inspection mode, A third step of inspecting the quality of the electronic unit by monitoring an output signal output from a predetermined output terminal of the electronic unit in accordance with the inspection control program in response to the input of the use signal; A fourth step of removing the external memory from the external memory connection terminal of the electronic unit after completion of the inspection. Is Dressings. FIG. 1 is a view showing a schematic configuration of an electronic unit and an inspection machine in an electronic unit inspection method according to an embodiment of the present invention, and FIG. It is a figure explaining the inspection process of the electronic unit including the inspection method of the electronic unit concerning the embodiment. In the electronic unit inspection method according to this embodiment, the inspection control program is set not in the internal memory of the microcomputer of the electronic unit but in a predetermined external memory. A method is used in which a memory is connected to an electronic unit, and the electronic control unit reads and executes an inspection control program set in the external memory. Therefore, as shown in FIG. 1, the electronic unit 1 in the method of inspecting the electronic unit 1 according to this embodiment is different from the electronic unit 101 in the conventional method in that a predetermined control program for the inspection is set. External memory connection terminal T11 to which the external memory is detachably connected
And a switching signal input terminal T10 for inputting a signal (switching signal) for causing the microcomputer 3 of the electronic unit 1 to execute the inspection control program in the external memory connected to the external memory connection terminal T11. Prepare. The switching signal input terminal T10 and the external memory connection terminal T11 are connected to the microcomputer 3 respectively. The microcomputer 3 is a conventional microcomputer 1
Compared to 03, the control program for inspection is not set in the internal memory 3a, only the control program for normal is set, and further, a switching signal is input to the electronic unit 1 via the switching signal input terminal T10. In this case, based on the switching signal, an inspection control program in the external memory connected to the external memory connection terminal T11 is executed to switch the operation mode to the inspection mode, and on the other hand, electronically via the switching signal input terminal T10. When the switching signal is not input to the unit 1, the configuration is the same except that a function for switching the operation mode to the normal mode by executing the normal control program set in the internal memory 3a is provided. Here, the microcomputer 3 has, for example, an option terminal T12, and if a switching signal is not input to the option terminal T12 at the time of activation, a program (here, a program) set in the internal memory 3a is set. A normal control program is read out and executed. If a switching signal is input to the option terminal T12 at the time of activation, a program (here, an inspection program) set in the external memory connected to the external memory connection terminal T11 is used. A program having a function of reading out and executing the control program) with priority is used. The other components of the electronic unit 1 are as follows.
Since the configuration is the same as that of the electronic unit 101 (FIG. 3) described in the related art, corresponding components are denoted by the same reference numerals and description thereof will be omitted. Correspondingly, the inspection machine 19 for inspecting the electronic unit 1 is further provided with a switching signal input terminal T on the electronic unit 1 side, as compared with the inspection machine 119 in the conventional method.
A switching signal output terminal S10 detachably connected to
An external memory providing terminal S11 is detachably connected to the external memory connecting terminal T11 of the electronic unit 1, and a storage device 43 in which an inspection control program functioning as the external memory is set. The switching signal output terminal S10 is connected to the control unit 21, and the external memory providing terminal S11 is connected to the storage device 43. The control unit 21 of the inspection machine 19
Compared to the conventional control unit 121, its power SW control circuit 2
7, the power supply switch 25 is turned on, the power of the power supply 23 is supplied to the power supply circuit 5 of the electronic unit 1 via the terminals S1 and T1, and the microcomputer 3 is started. By inputting a signal to the communication circuit 7 on the electronic unit 1 side via the terminals S2 and T2, instead of causing the microcomputer 3 of the electronic unit 1 to execute the inspection control program, the control unit 21 transmits the signal via the terminal S10. The power switch 25 is turned on by the power SW control circuit 27 while the switching signal of the present application is output, and the switching signal is input to the microcomputer 3 of the electronic unit 1 via the terminal T10 of the electronic unit 1. The power of the power supply 23 is supplied to the power supply circuit 5 of the electronic unit 1 via the terminals S1 and T1 to start the microcomputer 3, so that the microcomputer 3 of the electronic unit 1 The configuration is the same except that the test control program in the storage device 43 (external memory) connected to the external memory connection terminal T11 of the electronic unit 1 is set to be preferentially executed. ing. Note that the switching signal of the present application output from the inspection device 19 to the electronic unit 1 is stopped after the microcomputer is started, for example. The other components of the inspection machine 19 are the same as those of the inspection machine 119 (FIG. 3) described in connection with the prior art.
Corresponding components are denoted by the same reference numerals and description thereof is omitted. Next, a method for inspecting the electronic unit 1 will be described with reference to FIG. First, in step V1, electronic components are assembled, and a normal control program is set in the internal memory 3a of the microcomputer 3 of the electronic unit 1, whereby the electronic unit 1 is assembled. At step V2, the terminals S1 to S3, S5, S7 to S11 of the inspection machine 19 are connected to the electronic unit 1
To the corresponding terminals T1 to T3, T5, T7 to T11 to connect the inspection unit 19 to the electronic unit 1. Then, in step V3, the inspection machine 19 is operated to start the inspection machine 19. Thereby, the inspection machine 1
In the state where the switching signal is output from the switching signal output terminal S10 on the 9th side and is input to the microcomputer 3 via the switching signal input terminal T10 on the electronic unit 1 side, the terminal S on the inspection machine 19 side
1 to the terminal T1 on the electronic unit 1 side.
The electronic unit 1 is supplied to the microcomputer 3 via the power supply circuit 5 and is started. Then, in step V4, by the activation of the electronic unit 1, the external memory (inspection machine 19) connected to the external memory connection terminal T11 by the electronic unit 1 is started.
The inspection control program in the storage device 43) is read and executed, and the electronic unit 1 is shifted to the inspection mode. In this test mode, each test signal is sequentially output from each of the terminals S2, S3, and S5 on the tester 19 side and each terminal T on the electronic unit 1 side, as in the prior art.
2, T3, and T5, response signals are output from the terminals T2 and T8 of the electronic unit 1 in response to the input of the inspection signals, and input to the terminals S2 and S8 of the inspection machine 19. The inspection unit 19 inspects the quality of the electronic unit 1 based on the response signal. For example, the inspection is performed in the order of a switch input check, an AD input check, an output check, and the like. Then, in step V5, the electronic unit 1
In the case where the inspection result is judged to be defective (NG), the process proceeds to step V6, and the electronic unit 1 is once removed from the inspection routine and analyzed. The inspection is performed again from step V2. On the other hand, if the judgment of the inspection result is non-defective (OK), the process proceeds to step V7, where the inspection machine 19 (that is, the external memory 43) is removed from the electronic unit 1 and the process proceeds to step V8.
In the electronic unit 1, it is confirmed whether the normal control program is partially executed in the electronic unit 1 and the normal control program is normally executed (normal control operation confirmation), and the inspection is completed. Then, in step V9, the electronic unit 1 is packed and shipped. As described above, according to the method for inspecting the electronic unit 1, the electronic unit 1 is provided with the external memory connection terminal T11 and the switching signal input terminal T10, and the microcomputer 3 is provided with the switching signal. A function of executing a test control program in an external memory (the storage device 43 in the tester 19) connected to the external memory connection terminal T11 based on a switching signal input via the input terminal T10 is provided. Only when the electronic unit 1 has the external memory 4
The microcomputer 3 is connected to the microcomputer 3 to read and execute the inspection control program in the external memory 43 based on the switching signal, and removes the external memory 43 from the electronic unit 1 after the inspection is completed. The control program for inspection does not remain in the internal memory 1 of the microcomputer 103 as in the conventional method.
Therefore, the inspection control program is not erroneously executed at the place where the normal control program should normally control due to the failure of the microcomputer 3 or the application of noise to the terminal as in the related art. Malfunction can be prevented. According to the first aspect of the present invention, the electronic unit is provided with the external memory connection terminal and the switching signal input terminal, and the switching input through the switching signal input terminal. A function to execute a control program for inspection in the external memory connected to the external memory connection terminal based on a signal is provided.Only at the time of inspection, an external memory is connected to the electronic unit, and an external control is performed based on the switching signal. The inspection control program in the memory is read and executed, and after the inspection is completed, the external memory is removed from the electronic unit so that the inspection control program does not remain in the electronic unit. The control program for inspection is no longer permanently set in the electronic unit, so that the failure of the electronic unit and the application of noise to the terminals as in the conventional case are eliminated. This can prevent the inspection control program from being erroneously executed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing each schematic configuration of an electronic unit and an inspection machine in an electronic unit inspection method according to an embodiment of the present invention. FIG. 2 is a diagram illustrating an electronic unit inspection process including an electronic unit inspection method according to an embodiment of the present invention. FIG. 3 is a diagram showing an example of each configuration of an electronic unit and an inspection machine in a conventional electronic unit inspection method. FIG. 4 is a diagram illustrating a malfunction of an electronic unit which may occur when a conventional method for inspecting an electronic unit is employed. [Description of Signs] 1 Electronic unit 19 Inspection machine 43 Storage device T1 to T9 Input terminal, output terminal T10 Switching signal input terminal T11 External memory connection terminal

Claims (1)

In a normal mode, a predetermined output signal is output in response to an input signal input from a predetermined input terminal in a test mode according to a control program for the normal mode and in a test mode. A method for inspecting an electronic unit output from a terminal, wherein the electronic unit receives an external memory connection terminal to which a predetermined external memory in which the inspection control program is set is detachably connected, and a switching signal. And a function of executing the inspection control program in the external memory connected to the external memory connection terminal based on the switching signal input to the switching signal input terminal. Connecting the external memory in which the control program for inspection is set to the external memory connection terminal of the electronic unit. A step of inputting the switching signal to the switching signal input terminal of the electronic unit and causing the electronic unit to execute the inspection control program, thereby changing the operation mode of the electronic unit to the inspection mode. A second step of switching to, and while sequentially inputting a test signal to a predetermined input terminal of the electronic unit by the tester in the test mode, responding to the input of the test signal, according to the test control program, A third step of inspecting the quality of the electronic unit by monitoring an output signal output from a predetermined output terminal of the electronic unit; and after the inspection of the electronic unit is completed, the third step of connecting the external memory of the electronic unit. A fourth step of removing the external memory from a terminal.