JPS622339B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inspection device that checks the program of a microcomputer before it is installed in a product.

In recent years, the application of microcomputers has been remarkable.
It is used in a variety of products, and its testing plays an important role along with its software development.

Traditionally, checking the software of a microcomputer involves checking the entire memory contents, or checking the correctness of the software.
This method is based on preparing a CPU and comparing the response signals when the same signal as the sample is applied. However, although these methods allow checking the static state of memory contents, it is not possible to know whether they will work well when operated sequentially until they are incorporated into an actual circuit. For example, just by checking the contents of the memory, it is not possible to tell whether or not it will start from address zero when a reset signal is input. In addition, in the method of comparing CPUs, the sequence may not work properly depending on the external circuit, and such a method in which the actual usage state and the test state are different cannot be said to be the best.

Therefore, the present invention has been made to solve these problems, and particularly provides a device that can reliably check the quality of the program of a one-chip microcomputer with a built-in memory.

The inspection device of the present invention attaches the microcomputer under test to a socket attached to the microcomputer mounting part of a test board that has a test circuit with the same circuit configuration as the product board, and connects the microcomputer to a predetermined test point on the test board. Touch the check pin to
After enabling a control device configured to sequentially check all patterns of the program under test, the program is configured to run the program of the microcomputer under test according to the actual sequence and determine its acceptability. An embodiment of the present invention will be described below with reference to the drawings.

Figure 1 shows the configuration of an inspection device that pre-checks a 1-chip microcomputer with a built-in memory installed on a product board, where 1 is the microcomputer chip under test, and 2 is the microcomputer chip 1 after the test is installed. This is a normal product board whose operation has been checked in advance among the product boards that are used.Here, it is used as a test board that has a test circuit with the same circuit configuration as the product board, and there is no cover on the microcomputer mounting part. An IC socket 3 with the same number of pins as the test microcomputer chip 1 is installed. 4 is a signal interface, and the product board 2 as a test board and the signal interface 4 are connected to the connector 5 of the product board 2 itself through several check points, and the signal interface 4 is connected to the product board 2 as a test board through several check points. It consists of matching and protection circuits. Second
Figures a and b show a jig for mounting the product board 2, and the mount 6 on which the product board 2 is placed is moved down by rotating the lever 7 against the upward bias of the spring 8. It is configured to be vertically movable, and claws 9 are provided on the upper surface of the mount 6 to clamp the product board 2 between the mount 6 and the solder surface of the product board 2 by lowering the mount 6. The fixed side check pin 10 is configured to come into contact with the test point. Further, in FIG. 1, numeral 11 is a microcomputer as a control device that gives a predetermined pseudo signal to the product board 2 and checks a response signal from the product board 2 in response to the pseudo signal, and uses, for example, a Z80 CPU. It operates based on a memory 12 that stores a test procedure program. Reference numeral 13 denotes an I/O device interposed between the signal interface 4 and the microcomputer 11, which performs communication between the microcomputer 11 and the signal interface 4. Reference numeral 14 represents an NG signal, start and stop switches, and a mode indicator light on the console panel, which are controlled by the microcomputer 11.

Next, the operations of the microcomputer 11, memory 12 and I/O device 13 will be explained in detail based on the check operation.

In the check operation, first, the product board 2 on which the microcomputer chip 1 under test is mounted via the IC socket 3 is regarded as one completed product board, and the microcomputer 11 connects it to the completed product board via the signal interface 4. Provides a pseudo signal corresponding to the input signal in use. Next, the microcomputer 11 checks the response signal output from the product board 2 according to the program of the microcomputer chip 1 under test in response to the given pseudo signal, and checks the relationship between the pseudo signal and the response signal. All program patterns of computer chip 1 are sequentially checked. Since the product board 2 placed on the mount 6 is simulated in this way, the program in the memory of the microcomputer chip 1 to be tested can be checked in actual operation, and the quality of the program can be reliably checked. Further, since the product board to which the tested microcomputer chip 1 is mounted can be used as the test board to which the microcomputer chip 1 to be tested is mounted, there is no need to create a special test board.
Further, a jig as shown in FIG. 2 can be used for completing inspection of each product board with a microcomputer chip mounted thereon.

As explained above, according to the present invention, it is possible to easily and reliably check the software of a masked one-chip microcomputer in the final use state when receiving the chip, which is useful for production management of products using one-chip microcomputers. It has a great effect.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a configuration diagram of an inspection device, FIG. 2a is a plan view of a jig used for inspection, and FIG. 2b is a side view of FIG. 2a. . 1...Microcomputer chip under test, 2
...Product board [test board], 3...IC socket, 11...microcomputer [control device].

Claims (1)

[Claims] 1 An inspection device that checks in advance the program of a one-chip microcomputer with a built-in memory installed on a product board, which has a test circuit with the same circuit configuration as the product board, and has a test circuit on the part where the microcomputer is installed. A test board is provided with a socket to which a microcomputer chip can be attached and removed, a predetermined pseudo signal is applied to this test board according to the actual sequence, and a predetermined pseudo signal is applied to the test board according to the program of the microcomputer chip under test. a control device configured to sequentially check response signals outputted from the test board for all patterns of the program under test; 1. A program inspection device for a one-chip microcomputer, characterized in that a check pin is provided to enable the device to perform a check.