JPH04220577A - Electronic circuit testing method - Google Patents

Abstract

PURPOSE:To enable an abnormality of an electronic circuit to be detected at a high speed regarding an electronic circuit testing method for determining whether an operation is proper or not for an electronic circuit with a number of output terminals in the same way as in a liquid display drive circuit which drives a liquid display device. CONSTITUTION:Regarding an electronic circuit 101 which outputs a specified signal pattern from a plurality of output terminals for a specified input data, a criterion means 111 which stores a criterion information regarding whether an operation of the electronic circuit 101 is proper or not corresponding to all signal patterns which are output from the electronic circuit 101 in an electronic circuit testing method for determining if the operation is proper and outputs the corresponding criterion information with the signal pattern form the electronic circuit 101 as an address input, and a display means 121 for displaying the criterion information which is output by the criterion means 111 as a criterion result are provided.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic circuit testing method for determining the quality of operation of an electronic circuit having a large number of output terminals, such as a liquid crystal display drive circuit for driving a liquid crystal display device.

0002

[Prior Art] A liquid crystal display drive circuit is equipped with a large number of input terminals and output terminals corresponding to each of these input terminals, and amplifies the input signal to each input terminal in terms of power, and outputs the signal to the corresponding output terminal. The configuration is such that the data is input to the liquid crystal display device via the . With the development of semiconductor manufacturing technology, the number of liquid crystal elements integrated into liquid crystal display devices is increasing.
In response to this, liquid crystal display drive circuits have been configured to include a larger number of input terminals and output terminals.

[0003] When testing the operation of such a liquid crystal display drive circuit, a testing device inputs predetermined test data to each input terminal of the liquid crystal display drive circuit, and connects these input terminals with the corresponding output terminals. are sequentially selected to determine whether or not an output signal corresponding to the above-mentioned test data is being output. Thereby, it is possible to determine whether the parts related to input signals to each input terminal are operating normally.

[0004] Also, some test equipment includes a mechanism that sequentially selects input terminals and corresponding output terminals and connects the selected input terminals and output terminals to a circuit that automatically determines the output signal. Some test devices are equipped with such a configuration, making it possible to reduce the user's workload.

[0005]

[Problems to be Solved by the Invention] However, in the conventional method described above, output signals from a large number of output terminals provided in an electronic circuit are sequentially examined one by one, so the time required for testing is long. Ta. Further, according to the conventional method described above, it is possible to determine whether the operation is good or bad for each part related to each input terminal and the corresponding output terminal.
In some cases, it is only necessary to know whether there is an abnormal part in the electronic circuit.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electronic circuit testing method for detecting abnormalities in electronic circuits at high speed.

[0007]

[Means for Solving the Problems] FIG. 1 is a block diagram of the principle of the present invention. The present invention provides an electronic circuit test method for determining the quality of operation of an electronic circuit 101 that outputs a predetermined signal pattern from a plurality of output terminals in response to predetermined input data. Judgment means 111 stores judgment information regarding the quality of the operation of the electronic circuit 101 in correspondence with the signal pattern, and outputs the corresponding judgment information by using the signal pattern from the electronic circuit 101 as an address input; The present invention is characterized by comprising a display means 121 for displaying the determination information outputted by as a determination result.

[0008]

[Operation] According to the present invention, by inputting the signal pattern output from each output terminal of the electronic circuit 101 to the determination means 111 as an address, determination information corresponding to the above-mentioned signal pattern is outputted and displayed by the display means 121. Therefore, the determination result can be obtained faster than when checking each output terminal one by one.

[0009]

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings. 2, FIG. 4, FIG. 5, and FIG. 6 are configuration diagrams of an embodiment of a test device to which the electronic circuit test method of the present invention is applied. In the figure, the test device 210 includes a test data creation section 211, a timing control section 212, and a ROM 213.
and a flip-flop 214,
It is configured to determine whether the operation of the liquid crystal display drive circuit 201 is good or not, and to turn on the light emitting diode 215 corresponding to the display means 121 when an abnormality is detected.

Here, to simplify the explanation, the liquid crystal display drive circuit 201 has four input terminals I1 to I4.
The input signal to the corresponding output terminal O1 is amplified in terms of power.
~O4. The test data creation unit 211 described above alternately outputs two bit patterns "0101" and "1010" as test data, and inputs the first to fourth bits of each bit pattern to the input terminals I1 to I1.
The configuration is such that each input is input to I4.

FIGS. 3A to 3D show changes in the input signals to these input terminals I1 to I4. On the other hand, the outputs from the output terminals O1 to O4 of the liquid crystal display drive circuit 201 are input to the ROM 213 as a 4-bit address with the output of the output terminal O1 as the most significant bit.

This ROM 213 corresponds to the determining means 111, and when these addresses are obtained as the output of the liquid crystal display driving circuit 201 corresponding to each address, it is determined that the liquid crystal display driving circuit 201 is normal. 1-bit judgment information indicating whether or not each is stored. Here, when the liquid crystal display drive circuit 201 is operating normally, the waveforms of the output signals from the output terminals O1 to O4 change in the same way as the input signals to the corresponding input terminals I1 to I4. In this case, output terminals O1 to O4
The address "0101" (hereinafter referred to as address $5) and the address "1010" (hereinafter referred to as address $A) of the ROM 213 are alternately designated by the output signal from the ROM 213. On the other hand, if there is an abnormality in the liquid crystal display drive circuit 201, an address other than the above-mentioned address $5 and address $A is specified.

Therefore, as shown in Table 1, the ROM 213
Logic "0" is stored in addresses $5 and $A as determination information that the liquid crystal display drive circuit 201 is normal, and logic "1" is stored in other addresses as determination information that there is an abnormality.
All you have to do is store it.

[0014]

[Table 1]

Furthermore, the timing control section 212 is configured to operate in synchronization with the above-described test data creation section 211, and as shown in FIG. A signal that rises after a delay of time τ is sent to the flip-flop 214 as a clock signal. Since the flip-flop 214 operates in response to this clock signal, the determination information corresponding to the designated address of the ROM 213 can be held while the output of the liquid crystal display drive circuit 201 is stable.

The output terminal of this flip-flop 214 is grounded via the above-mentioned light emitting diode 215, and when the logic "1" is held in this flip-flop 214, the light emitting diode 215 lights up and the liquid crystal A message indicating that an abnormality in the display drive circuit 201 has been detected is displayed. For example, if the output from output terminal O1 is fixed at logic "0", the above bit pattern "10"
10", the output terminals O1 to O4 of the liquid crystal display drive circuit 201, as shown in FIGS. 3(f) to (i),
are respectively logic “0”, logic “0”, logic “1”,
Outputs logic “0”. In FIG. 3(f), the dotted line is
It shows the change in the output signal under normal conditions.

In this case, as shown in FIG. 3(j), R
Address $2 and address $5 of OM213 are alternately designated, and when address $2 is designated, logic "1" is output from ROM213 as determination information. At this time, the determination information is held in the flip-flop 214 (see FIG. 3(k)) according to the above-mentioned clock signal (see FIG. 3(e)), and the above-mentioned light emitting diode 2
15 lights up.

In this way, the four output terminals O1 to
The output signal from O4 is sent to RO as a 4-bit address.
By inputting to M213, the liquid crystal display drive circuit 20
It is possible to obtain determination information indicating whether or not 1 is normal. In this case, after inputting the above-mentioned two bit patterns as test data, it is possible to detect an abnormality in the liquid crystal display drive circuit 201 almost instantly, and the time required to test the electronic circuit can be significantly shortened. This can reduce the burden on test workers.

Further, the test device 210 may be configured to obtain determination information including information indicating an abnormal location in accordance with the output of the liquid crystal display drive circuit 201. In this case, as shown in FIG. 4, in place of the ROM 213 described above, a ROM 413 is provided that stores 4-bit determination information in each address, and the four flip-flops 214a to 214d are connected to the clock signal from the timing control section 212. The configuration may be such that each bit of the determination information is held in synchronization with the . Furthermore, four light emitting diodes 215a to 215d are provided corresponding to these flip-flops 214a to 214d, and are configured to be turned on according to the corresponding bit of the determination information.

[0020] Here, the above-mentioned bit pattern "010
1” and “1010”, the address is $5, respectively.
If a value other than $A is specified, it is considered that there is an abnormality in the part related to the output terminal corresponding to the bit position where the specified address is different from address $5 or address $A. In this way, for each address in the ROM 413, possible abnormalities are analyzed when the bit pattern indicating this address is output by the liquid crystal display drive circuit 201, and depending on the obtained abnormality, the determination information is determined. The bit position to be set may be set to logic "1". Table 2 shows the determination information thus obtained. However, since the abnormal location cannot be identified for addresses $0, $3, $6, $9, $C, and $F, "1111" is stored as determination information in each of these addresses. Further, "0000" is stored as determination information in addresses $5 and $A indicating a normal state.

[0021]

[Table 2]

For example, as shown in FIG. 3, the liquid crystal display drive circuit 2 corresponding to the input of the bit pattern "1010"
If the address $2 of the ROM 413 is specified by the output of 01, the determination information "
1000” is obtained, and the flip-flops 214a to 21
4d respectively. In response, the light emitting diode 215a corresponding to the flip-flop 214a lights up, and the output terminal O1 corresponding to the first bit of the determination information is turned on.
A message is displayed indicating that there is an abnormality in the related part.

In this way, the liquid crystal display drive circuit 201
If there is an abnormality, it is possible to obtain determination information including information about the abnormal location and display that fact. Even in this case, the above-mentioned determination information can be obtained almost instantaneously in response to input of test data. Furthermore, as shown in FIG. 5, when the light emitting diode 501 to which the power supply voltage is applied is connected in the forward direction to one of the output terminals (for example, the output terminal O1) of the liquid crystal display drive circuit 201, the light emitting diode 501 blinks. It may be configured to monitor whether or not the

[0024] As a result, the output of the liquid crystal display drive circuit 201 does not change in response to changes in test data, and the output from the ROM 21
Even when the output is fixed to the address $5 or address $A of 3, the above-mentioned light emitting diode 50
Depending on the presence or absence of blinking 1, such an abnormality can be detected without being overlooked, and the reliability of the test results by the test device 210 can be improved.

Furthermore, as shown in FIG.
The testing apparatus 210 may be configured to include a RAM 613 instead of the ROM 413 or the ROM 413, and the determination information in the RAM 613 may be changed by the personal computer 620. This makes it possible to test electronic circuits that output different bit patterns in response to input of the above-mentioned test data, and allows the same test device 210 to flexibly test various electronic circuits. can.

[0026] In addition, by rewriting the judgment information depending on whether or not the user requests information regarding abnormalities in the electronic circuit, the test can be performed flexibly in response to such user requests. be able to. Note that the electronic circuit testing method of the present invention is not limited to the above-mentioned liquid crystal display drive circuit.
The present invention can be applied to any electronic circuit that can determine the quality of its operation based on output bit patterns corresponding to several input bit patterns.

[0027]

Effects of the Invention As explained above, the present invention inputs addresses of signal patterns output from a plurality of output terminals of an electronic circuit into a determination means to obtain corresponding determination information, so that an abnormality in an electronic circuit can be detected quickly. This makes it possible to reduce the time required to test electronic circuits and reduce the burden on test workers.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the principle of the present invention.

FIG. 2 is a configuration diagram of an embodiment of a testing device to which the electronic circuit testing method of the present invention is applied.

FIG. 3 is a timing diagram showing the operation of the test apparatus shown in FIG. 2;

FIG. 4 is a configuration diagram of an embodiment of a testing device to which the electronic circuit testing method of the present invention is applied.

FIG. 5 is a configuration diagram of an embodiment of a testing device to which the electronic circuit testing method of the present invention is applied.

FIG. 6 is a configuration diagram of an embodiment of a testing device to which the electronic circuit testing method of the present invention is applied.

[Explanation of symbols]

101 Electronic circuit 111 Judgment means 121 Display means 201 Liquid crystal display drive circuit 210 Test equipment 211 Test data creation department 212 Timing control section 213,413 ROM 214 Flip-flop (FF) 215,501 Light emitting diode 613 RAM 620 Personal computer

Claims (1)

[Claims] Claim 1: An electronic circuit (1) that outputs a predetermined signal pattern from a plurality of output terminals in response to predetermined input data.
Regarding 01), in the electronic circuit test method for determining the quality of operation, the electronic circuit (101) is
Judgment means (111) stores judgment information regarding the quality of the operation of the electronic circuit (101), and outputs corresponding judgment information by using the signal pattern from the electronic circuit (101) as an address input.
and display means (121) for displaying the judgment information outputted by the judgment means (111) as a judgment result.