JPS63300975A - Testing method for printed board - Google Patents

Abstract

PURPOSE:To improve the test accuracy of a printed board to be tested where a CPU is mounted by connecting the printed board to a personal computer as a testing device through digital connectors and a serial communication line and transmitting data forward and backward. CONSTITUTION:The printed board 3 to be tested where the CPU is mounted and the personal computer as the testing device are connected by respective input/output connectors 7 and the serial communication line 8. Then the computer 12 sends an input transmission request and a transmission data output request to the printed board 3 by serial transmission. While those requests are transmitted, the computer 12 collates specific data sent to the printed board 3 through the connector 7 or 8 with data corresponding to the specific data obtained from the printed board 3 through the connector 7 or 8. Thus, the digital input/output function of the printed board 3 except in stationary operation is tested, so a test including the function of the CPU on the printed board 3 is conducted and the test accuracy is improved.

Description

[Detailed description of the invention] [Industrial application field]

The present invention includes a CPU, a digital parallel signal input/output connector,
It also relates to test methods for testing devices under test such as printed circuit boards equipped with serial communication means using test computer equipment such as personal computers. The present invention relates to a method of testing whether a pattern signal is input/output. Note that in the following figures, the same reference numerals indicate the same or corresponding parts.

[Conventional technology]

Conventionally, in order to test a printed board that is equipped with a CPU and is controlled and operated by serial communication, serial communication is performed under the same conditions as when the printed board is operated in an actual product, and the printed board is tested. A test was conducted to examine the input/output signals exchanged between the printed board and the peripheral devices by operating the board in a steady state. Next, this test method will be explained using FIG. FIG. 4 is a block diagram showing the configuration of a conventional test circuit of this type. In the figure, 1 is the product under test. 2 is a computer as a test device; 3A and 3B are printed boards built into the product under test 1; 5 is a CPU in each printed board 3A and 3B; 7 is a digital parallel signal input/output connector; 6 is also the ink face for input/output connector 7, 8 is the CPU in print + ffaA
5 and the CPU 5 in the printed board 3B. In response to signals input from the outside, the two CPUs 5 output signals to the input/output connector 7 in their own printed circuit board, or issue commands to the other printed board (CPU) via the serial communication line 8. I'm putting out some things. The test computer 2 provides an input signal during the normal operation of the product under test 1 to the input/output connector 7 of the printed board, and based on the input signal, the printed board 3A or 3
A test is performed in which the signal outputted by the CPU 5 of the computer B to the input/output connector 7 of the product 1 is taken into the computer 2 side and compared with an expected value.

[Problems to be solved by the invention]

However, the above test method has the following problems. (1) Since the test can only be performed according to the steady operation pattern during product operation, and therefore it is not possible to input and output signals of any pattern, the connector 7 on the printed board of the product It is not possible to determine signal errors that rarely occur instantaneously at any pin position. (2) Since the product operates by a combination of the respective printed boards 3A and 3B, it is impossible to test the printed boards alone. (3) When testing a single printed board, it is impossible to perform an overall functional test including the operation of the CPU, even if a commercially available in-circuit tester or the like is used. The object of the present invention is to connect a printed circuit board under test equipped with a CPU and a personal computer as a test device through their respective digital input/output connectors and serial communication lines, and input data from the personal computer to the printed board under test through serial communication. While transmitting a transmission request or a transmission data output request, the personal computer first sends predetermined data to the printed circuit board under test via the digital input/output connector or serial communication line, and the same input/output connector or serial communication line. By comparing this predetermined data obtained from the printed circuit board under test with the corresponding data, it is possible to check the digital output of any pin at any position of any input/output connector without being affected by the steady operation of the printed circuit board under test. The purpose of this method is to allow input/output signal functions to be freely specified and tested using a plurality of test patterns.

[Means to solve the problem]

In order to achieve the above object, the method of the present invention
U (5, etc.), instep side digital input/output means (input/output connector 7, etc.) that inputs or outputs digital parallel signals
, and serial communication means (serial communication line 8, etc.) on Party A's side for performing serial communication. Party B side digital output means for inputting or outputting parallel signals (input/output connector 7
etc.) and a B side serial communication means (serial communication line 8 etc.) for performing serial communication. The input/output means and the digital input/output means on the Party B side are connected to each other, and the serial communication means on the Party A side and the serial communication means on the Party Party B side are connected to each other so that signals can be exchanged, respectively, and the test device is connected to the outputting a parallel signal corresponding to predetermined first test data via the digital input/output means on the second side, and sending an input data transmission request to the device under test via the serial communication means on the second side; The device transmits the instep input data corresponding to the parallel signal inputted through the instep digital input/output means to the instep serial communication based on the input data transmission request received via the instep serial communication means. (and ) The test device transmits a transmission data output request and predetermined second test data to the device under test via the serial communication means on the second side, and the device under test Based on the received transmission data output request and the second test data, a parallel signal corresponding to the second test data is outputted via the digital input/output means on the Party A side, and the test device outputs a parallel signal corresponding to the second test data on the Party A side. It is assumed that the second test data is compared with the second test data, which corresponds to the parallel signal input via the digital input/output means.

[For use]

The present invention connects the digital parallel signal input/output connector and serial communication line of the printed circuit board under test equipped with a CPU to the corresponding input/output connector and serial communication line of the test equipment, and connects the test equipment and the printed board under test. By sending and receiving data through the input/output connector while performing serial communication in test mode, in other words, the test equipment sends an input data transmission request to the printed circuit board under test via serial communication, and outputs it from the input/output connector of the test equipment. Read the signal to the printed board under test,
The read data can be sent to the test equipment via the serial communication line, or a transmission data output request can be sent from the test equipment to the printed board under test via serial communication, and the test equipment can send the printed board under test via the serial communication line. The input/output function of digital parallel signals can be tested by outputting a signal corresponding to the data sent to the input/output terminal of the printed circuit board under test.
Furthermore, by equipping the personal computer with a program that can create a plurality of test patterns as files, it is possible to perform a wide variety of printed board tests and to easily change the test patterns.

【Example】

The present invention will be explained in detail below using FIGS. 1 to 3. FIG. 1 is a block diagram showing the configuration of a test circuit as an embodiment of the present invention, and corresponds to FIG. 4. Figure 2,
FIG. 3 is a flowchart illustrating the test procedure in FIG. 1. In FIG. 1, 3 is a printed board to be tested on which the CPU 5 is mounted. As software for the CPU 5, a regular operation program and a test program are resident in a memory (not shown). The digital parallel signal input/output connector of the printed circuit board 3 is connected via the ink face 6 to a personal computer (also abbreviated as a tester) 12 as a testing device. Further, the serial communication line 8 of the printing cloth 3 is also connected to a CPU (not shown) in the tester 12 via the ink face 6 on the personal computer 12 side. The input signal and output signal from the input/output connector 7 of the printed board 3 under test are tested by the method shown below. (I) During input signal testing (see Figure 2) The tester 12 selects the connector (
A signal is applied to the designated numbered connector bin (included in the input/output connector 7) (step 511). Here, the test pattern is a data pattern consisting of binary values for each bin number in the connector 7, that is, for each signal line of the digital parallel signal, and is specifically set for testing. Next, the number of the connector bin to which the signal was applied from the tester 12 is notified to the CPU 5 of the printed board under test by serial communication via the serial communication line 8 (step 512).
. The CPU 5 of the printed board under test inputs the connector bin signal of the specified number (step 513), and sends the signal data back to the tester 12 via serial communication (step 514). The tester 12 determines whether or not the received signal data matches the signal data that it first applied (step 515), and if they match, it moves to the next test item (step 5169 branch Y). If it is different (step 8161 branch N), alarm processing is performed (step 517) and the process moves to the next test item. (n) During output signal testing (see Figure 3) From the tester 12 side, according to the set test pattern, input the connector bin number and output signal to be tested, for example, "B connector number 2. 4. 6. 8. "Apply a signal to the pin" via serial communication to the CPU 5 of the printed board under test (step 521). Next, the CPU 5 of the printed board under test applies a signal to the specified bin number of the specified connector (step 522
). The tester 12 inputs the signal from the input/output connector 7, checks whether it matches the expected value (step 523), and if it matches (step 8161 branch Y), moves on to the next test item. If it is different (step 8161 branch N), alarm processing is performed (step 517) and the process moves to the next test item. In this way, the input and output signals at the input/output connector 7 of the printed circuit board 3 under test are tested, but the test pattern and test item contents can be easily created by creating a file on the personal computer 12. It can be changed, added to, or deleted.

【Effect of the invention】

According to the present invention, a printed board under test equipped with a CPU and a personal computer serving as a test device are connected through their respective input/output connectors and serial communication lines, and the printed board under test is connected to the printed board under test in a program mode for testing. While transmitting an input data transmission request and a transmission data output request through serial communication to the PC board, the personal computer transmits the same input/output data as the initial data sent to the printed circuit board under test via the digital input/output connector or serial communication line. This predetermined data obtained from the printed board under test via the connector or serial communication line is compared with the corresponding data, making it possible to test digital input/output functions other than the normal operation of the printed board under test. Therefore, it is possible to perform tests that include the functions of the CPU of the printed board under test, which has the effect of improving test accuracy.In addition, during steady operation, even for printed boards that cannot be tested with a single printed board, tests can be performed on the CPU of the printed board under test. By installing the program, it is possible to test a single printed board. Furthermore, by changing the test pattern in the file on the personal computer side, it is possible to easily change the test content. Furthermore, since a personal computer can have a plurality of test patterns, a variety of printed board tests can be performed with one personal computer.

[Brief Description of the Drawings] Figure 1 is a block diagram showing the configuration of a test circuit as an embodiment of the present invention, Figures 2 and 3 are flowcharts explaining the test procedure in Figure 1, and Figure 4. is a block diagram of a conventional circuit corresponding to FIG. 1; 3: Printed board under test, 5: CPU, 7: Input/output connector, 8 real communication line, 12: Par Figure 1

Claims (1)

[Scope of Claims] 1) A printed board device under test that includes a CPU on the first side, a digital input/output means on the first side for inputting or outputting digital parallel signals, and a serial communication means on the first side for performing serial communication. A method for testing printed circuit boards using a testing device equipped with a CPU on the second side, a digital input/output means on the second side for inputting or outputting digital parallel signals, and a serial communication means on the second side for performing serial communication. In this case, the digital input/output means on the Party A and the digital input/output means on the Party B are connected to each other, and the serial communication means on the Party A and the serial communication means on the Party B are connected to each other so that signals can be exchanged. , the test device outputs a parallel signal corresponding to predetermined first test data via the digital input/output means on the second side, and requests the device under test to send input data via the serial communication means on the second side. Based on the input data transmission request received via the A-side serial communication means, the device under test transmits the A-side input data corresponding to the parallel signal input via the A-side digital input/output means. is transmitted to the testing device via the serial communication means on the Party A side, and the testing device compares the input data on the Party A side received via the serial communication means on the Party B side with the first test data. or (and) the test device transmits a transmission data output request and predetermined second test data to the device under test via the serial communication means on the party B, and the device under test is transmitted to the device under test on the party A’s side. Based on the transmission data output request and second test data received via the serial communication means, output a parallel signal corresponding to the second test data via the instep digital input/output means; A method for testing a printed circuit board, characterized in that the test device compares the second test data with input data on the second side corresponding to the parallel signal inputted through the digital input/output means on the second side. .