JPH07104798B2 - Fault detection device for digital circuits - Google Patents

Description

The present invention relates to a fault detection device for a digital circuit, and more particularly to a design information holding device that holds a logic circuit diagram of the digital circuit as design information, and a circuit of the digital circuit. Regarding a fault detection device of a digital circuit comprising a figure and a state information collecting device for displaying the states of input / output terminals on a display device, it is possible to easily detect a faulty portion of the digital circuit in a short time. For the purpose of the above, in the fault detection apparatus for a digital circuit, a state information output means for outputting the state of each input / output terminal of the digital circuit displayed on the display device, and a design for outputting design information of a logic circuit diagram of the digital circuit Information output means, logic circuit diagram display means for displaying a logic circuit diagram, and a simulator for causing a logic circuit to perform a simulation based on state information. The rate control means is provided.

[Industrial application field]

The present invention relates to a fault detection device for a digital circuit, and more particularly, to a design information holding device that holds a logic circuit diagram of the digital circuit as design information, a circuit diagram of the digital circuit, and a state of input / output terminals. The present invention relates to a fault detection device for a digital circuit, which includes a status information collection device displayed on the device.

Digital circuits are widely used in electronic computers,
The drawing is complicated and enormous in number, and it is very difficult to investigate a defective circuit or a logic error on the drawing. Therefore, in the investigation of such digital circuits, there is a need for a failure detection device capable of easily detecting a failure in a short time.

[Conventional technology]

2. Description of the Related Art Conventionally, there is, for example, a device shown in FIG. 4 as a fault detection device for a digital circuit of an electronic computer.

In the figure, 11 is a digital circuit constituting an electronic computer (not shown) to be surveyed, 12 is a device for maintenance and inspection provided independently of the electronic computer, and a display device 14
Or a state information collecting device (hereinafter, referred to as a service processor) that includes an input device 15 and the like, and displays a circuit diagram of the digital circuit 11 on the screen of the display device 14 by the flip-flop and a state of input / output terminals of the flip-flop. ),13
FIG. 3 is a logic circuit diagram of a digital circuit of an electronic computer printed on a plurality of sheets of paper or the like. In this logic circuit diagram 13, all of the logic circuit diagrams constituting a digital circuit such as an AND gate and an OR gate in addition to the flip-flop displayed on the display device 14 are shown. In addition, the display device 14
The screen is divided into, for example, four blocks, and one block is also divided into about 500 points, and a circuit diagram by a flip-flop of a digital circuit is displayed for each point.

In the investigation of the faulty part of the digital circuit 11 by the service processor 12 as described above, first, the circuit diagram by the flip-flop of the digital circuit 11 is displayed at each point of the screen of the display device 14 of the state information collecting device 12, and which point is displayed. It is predicted whether there is a fault in the circuit diagram by referring to the states of the input / output terminals of each flip-flop. Then, after predicting the point where there is a possibility of failure, write the state of the input / output terminal of each flip-flop in the circuit diagram there to the input / output terminal of each flip-flop in the logic circuit diagram 13 corresponding to the circuit diagram, and Investigate whether the circuit or each flip-flop is operating normally and detect the abnormal part.

[Problems to be Solved by the Invention]

By the way, in detecting a fault in a digital circuit by such a conventional state information collecting apparatus, the location of the digital circuit is very complicated even though the configuration of the digital circuit is very complicated and the number of logic circuit drawings is enormous. When it is attempted to detect whether there is a failure or a failure in the flip-flop, first, as described above, the failure location is predicted on the display device 14 of the service processor 12, and the current state of the input / output terminal of the flip-flop is grasped. It is necessary to perform a series of operations of writing the state in the input / output terminal of the flip-flop of the logic circuit diagram corresponding to the digital circuit and performing arithmetic operation by the logic circuit. If no abnormality is detected there, The above series of operations had to be repeated until an abnormal digital circuit could be detected.

Therefore, in the conventional method, it takes a lot of time and labor to detect the faulty part of the digital circuit.
There was also the problem of poor work efficiency.

Therefore, it is an object of the present invention to provide a fault detection device for a digital circuit that can easily detect a faulty portion of the digital circuit in a short time.

[Means for Solving the Problems]

In the present invention, means for solving the above problems,
As shown in FIG. 1, a design information holding device 2 which holds a logic circuit diagram of the digital circuit 1 as design information, a circuit diagram of the digital circuit 1 and states of input / output terminals are displayed on a display device 3. In the fault detection device for the digital circuit, which comprises the status information collecting device 4 for
Status information output means 5 for outputting the status of each input / output terminal of the digital circuit 1 displayed as status information, and the design information of the logic circuit diagram of the digital circuit 1 displayed on the display device 3 is held as the design information. Design information output means 6 output from the device 2, logic circuit diagram display means 7 for displaying the logic circuit diagram of the digital circuit displayed on the display device 3 based on the design information from the design information output means 6, and logic The state information of each input / output terminal of the digital circuit 1 displayed on the display device corresponding to the input / output terminal is given to the input / output terminal of the logic circuit diagram displayed on the circuit diagram display means 7,
The simulation control means 8 is provided for causing the logic circuit to perform a simulation based on the state information.

[Action]

The operation of the present invention will be described with reference to FIG. 1. The state information output means 5 changes from the state information collecting device 4 to the display device 3 thereof.
The state of the input / output terminal of each flip-flop of the digital circuit displayed in is output as state information. Further, the design information output means 6 outputs information necessary for displaying the logic circuit diagram of the digital circuit from the design information holding device 2 as design information. The logic circuit diagram display means 7 displays a logic circuit diagram based on the logic design information from the design information output means 6. Then, the simulation control means 8 is connected to the input / output terminals of each flip-flop of the displayed logic circuit diagram,
The state information of the input / output terminals of each flip-flop of the digital circuit 1 displayed on the display device corresponding to the input / output terminals is given, and the logic circuit connected to each flip-flop is caused to perform a simulation based on the state information. .

Therefore, the logic circuit diagram of the digital circuit can be displayed on the logic circuit diagram display means 7, and at the same time, the result of the simulation of the logic circuit of the logic circuit diagram can be displayed on the logic circuit diagram display means 7.

〔Example〕

An embodiment of a fault detecting apparatus for a digital circuit according to the present invention will be described below with reference to the accompanying drawings.

In this embodiment, as shown in FIG. 2, the service processor
21, a design information holding device 31, an information output device 41, and a logic circuit diagram display device 51. The digital circuit 81 constitutes an electronic computer (not shown) to be investigated.

The service processor 21 is similar to the conventional one, and includes a display device 22 such as a CRT, a circuit display control unit 23, an input device 24 such as a keyboard, and a state detection unit 25. The circuit display control unit 23 stores in advance information for displaying the state of the flip-flop of each digital circuit 81 on the display device 22, and displays the state of the digital circuit 81 on the display device 22 according to a command from the input device 24. It is what makes me. Further, the input device 24 designates the digital circuit 81 to be displayed on the display device 22 and also designates an arbitrary point on the circuit diagram of the digital circuit 81 displayed on the display device 22 on the screen of the display device 22. is there. Then, the state detection unit 25 is a display device.
The state of the input / output terminal of each flip-flop of the digital circuit 81 displayed at 22, that is, the state of the terminal is H level "1"
Or an L level "0" is detected from the electronic computer.

Further, the design information holding device 31 shows a logic circuit diagram in which the digital circuit is shown by a logic circuit such as a flip-flop and an AND gate or an OR gate, and the circuit information indicating the flip-flop and the logic circuit and the connection state thereof. It is previously stored as design information with the connection information shown.

On the other hand, the information output device 41 outputs the state of the input / output terminal of each flip-flop of the digital circuit 81 displayed on the display device 22 at a point designated by the input device 24 from the state detection unit 25 as state information. , A status information output unit 42 for sending it to the logic circuit diagram display device 51, and a service processor.
Based on the command from the input device 24 of 21, the design information holding device 31
From the digital circuit 81 displayed on the display device 22, the circuit information and the connection information of the logic circuit diagram corresponding to the point designated by the input device 24 are output, and the circuit drawing display device is displayed.
And a design information output unit 43 sent to 41.

The logic circuit diagram display device 51 has a logic circuit diagram display unit 52 such as a high-resolution bitmap display, an information display control unit 61, a display screen control unit 71, and an input device 53 such as a mouse. The information display control unit 61 displays the logic circuit diagram on the logic circuit diagram display unit 52, receives the design information of the logic circuit drawing from the design information output unit 43, recognizes the circuit information and the connection information, and separates them from each other. And output the design information recognition unit 62,
A circuit information display control unit for displaying a logic circuit or the like on the logic circuit diagram display unit 52 based on the circuit information from the design information recognition unit 62.
63, and a connection information display control unit for displaying the connection on the logic circuit diagram display unit 52 based on the connection information from the design information recognition unit 62.
64 and. Further, the logic circuit diagram display device 51 has a state information output unit at the input / output terminals of each flip-flop of the logic circuit diagram of the digital circuit displayed on the logic circuit diagram display unit 52.
The state information of the input / output terminal of the flip-flop of the circuit corresponding to the flip-flop sent from 42 is given, and the logic circuit connected to each flip-flop is simulated based on the state information, and the result is obtained. It has a simulation control unit 65 and a simulation display control unit 66 that controls the logic circuit diagram display unit 52 to display the result of the simulation.

Further, the display screen control unit 71 controls the display state of the logic circuit diagram display unit 52 on the screen, and enlarges or reduces the result of the logic circuit diagram or simulation displayed on the screen. The enlargement / reduction display control unit 72 for controlling the screen, the scroll display control unit 73 for scrolling the screen, and the drawing name displayed on the screen,
It has a history display control unit 74 for displaying the drawing names and numbers that have been displayed in the logic circuit diagram display unit 52 up to now together with the drawings.

Next, description will be made with reference to the flowchart of this embodiment shown in FIG.

First, a digital circuit which is likely to have a failure is designated by the input device 24, and the digital circuit is displayed on the display device 22 of the service processor 21. Then, by observing the digital circuit, it is predicted at which functional block or point the digital circuit is faulty by the state of the input / output terminal of the flip-flop of the digital circuit, and the point is input by the input device 53. Specify by (ST
1).

Then, from the input device 53 to the design information output unit 43,
A command for specifying a point on the circuit diagram of the digital circuit 81 currently displayed on the display device 22 is sent. Based on the instruction, the design information output unit 43 selects and outputs the circuit information and the connection information of the logic circuit diagram corresponding to the digital circuit 81 displayed on the display device 22 from the design information holding device 31. In addition, the status information output unit 42 includes the status detection unit 25 to the display device 22.
The state of the input / output terminal of each flip-flop of the digital circuit 81 displayed at is output as state information. And
This information is sent to the logic circuit diagram display device 51 (ST
2).

Next, when displaying the logic circuit diagram on the logic circuit diagram display unit 52,
It is determined whether the display state is designated as, for example, enlargement / reduction (ST3). If you do not specify the display state,
Display the logic circuit diagram and the result of the simulation as usual. On the other hand, when designating the display state, "enlargement / reduction display", "scroll display", or "history display" is selected. When "enlarge / reduce display" is selected, the enlargement / reduction display control unit 72 enlarges or reduces the display of the logic circuit diagram or the simulation result displayed on the screen of the logic circuit diagram display unit 52. Control to do so (ST4). On the other hand, when "scroll display" is selected, the scroll display control unit 73 controls the screen display to scroll (ST5), and when "history display" is selected, the screen is displayed. The displayed drawing name and the drawing name and number that have been displayed in the logic circuit diagram display section 52 are controlled so as to be displayed together with the drawing (ST6).

In the logic circuit diagram display device 51, the design information output unit 43
The design information recognition unit 62 receives the design information from the circuit, recognizes the circuit information and the connection information and outputs them separately, and the circuit information display control unit 63 displays the logic circuit etc. on the basis of the circuit information. On the other hand, the connection information display control unit 64 displays the connections on the logic circuit diagram display unit 52 based on the connection information (ST7).

Further, the simulation control unit 65 uses the information indicating the state of the input / output terminals of each flip-flop, which is sent from the state information output unit 42, for each flip-flop of the logic circuit diagram displayed on the logic circuit diagram display unit 52. The logic circuit connected to each flip-flop is simulated based on the state information given to the input / output terminal (ST8). Then, the simulation display control unit 65 displays the result as the logic circuit diagram display unit 52.
To be displayed (ST9).

Then, finally, it is determined from the simulation result displayed on the logic circuit display section 52 whether or not the flip-flop and the logic circuit are normally operating (ST10). If a failure is detected in the flip-flop or logic circuit, the investigation ends. If no failure is detected, another point is searched and the abnormal operation is repeated from the beginning (ST
1 ~ ST10).

As described above, according to this embodiment, the logic circuit diagram of the digital circuit is displayed on the logic circuit diagram display unit 52, and at the same time, the flip-flops of the digital circuits displayed on the display device 22 of the service processor 21 are displayed. The status of the input / output terminal is displayed in the logic circuit diagram display section 52 corresponding to the input / output terminal.
Since it is applied to the input / output terminals of the flip-flop displayed in the above, the logic circuit connected to each flip-flop is simulated based on the status information, and the result is displayed in the logic circuit diagram display section 52. Therefore, the failure investigation of the digital circuit can be performed easily in a short time.

In the present embodiment, the display screen control unit 71 has an enlargement / reduction display control unit 72, a scroll display control unit 73, and a history display control unit 74 so that the display of the screen can be efficiently confirmed, or It is provided so as to facilitate the investigation, and is not necessarily provided in the present invention.

〔The invention's effect〕

As described above, according to the present invention, the logic circuit diagram of the digital circuit is displayed on the logic circuit diagram display means, and at the same time, the flip-flops of the digital circuit displayed on the display means of the status information collecting device are turned on. The state of the output terminal is given to the input / output terminal of the flip-flop displayed on the logic circuit diagram display means corresponding to the input / output terminal, and the logic circuit connected to each flip-flop is simulated based on the state information. In addition, since the result is displayed on the logic circuit diagram display means, it is possible to easily and quickly investigate the faulty part of the digital circuit.

[Brief description of drawings]

FIG. 1 is a principle diagram of the present invention, FIG. 2 is a diagram showing a configuration of fault detection means of a digital circuit according to an embodiment of the present invention, and FIG.
FIG. 4 is a diagram showing the operation of the present embodiment, and FIG. 4 is a diagram showing a conventional example. 1 ... Digital circuit 2 ... Design information holding device 3 ... Display device 4 ... State information collecting device 5 ... State information output means 6 ... Design information output means 7 ... Logic circuit diagram display means 8 ... Simulation Control means

Claims (1)

[Claims] 1. A design information holding device (2) for holding a logic circuit diagram of a digital circuit (1) as design information, a circuit diagram of the digital circuit (1), and a display device for displaying the states of input / output terminals. Status information collection device displayed in (3) (4)
A fault detection apparatus for a digital circuit comprising: a digital circuit (1) displayed on the display device (3).
Status information output means (5) for outputting the status of each input / output terminal as status information, and the digital circuit (1) displayed on the display device (3).
The design information of the logic circuit diagram of the above-mentioned design information holding device (2)
And a logic circuit diagram display means for displaying the logic circuit diagram of the digital circuit displayed on the display device (3) based on the design information from the design information output means (6). (7) and each of the digital circuits (1) displayed on the display device (3) corresponding to the input / output terminal of the logic circuit diagram displayed on the logic circuit diagram display means (7). A fault detection apparatus for a digital circuit, comprising: a state-information input / output terminal; and a simulation control means (8) for causing a logic circuit to perform a simulation based on the state information.