JP3093335B2 - Automatic creation method of integrated circuit test program - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to automatic generation of a test program for an integrated circuit.

[0002]

2. Description of the Related Art With respect to automatic creation of test programs for integrated circuits, automation using computer simulation has been advanced in digital integrated circuits, such as automatic creation using logic simulation result data in the logic design stage. . However, most of the analog integrated circuit test programs are manually created, which is a part of automation of the integrated circuit development process, and is a process in which errors due to manual work are likely to occur.

[0003]

The following two points are particularly difficult when manually creating a test program.

The first is to specify a combination to be tested for each combination of an input terminal, an output terminal, and a control terminal.
For example, in an integrated circuit having two input terminals, two output terminals, and two control terminals, there are a total of eight combinations, but in an actual integrated circuit, the number of input terminals and the number of output terminals are:
More and more, it is necessary to consider various combinations.

Second, a test standard value of each combination is determined. That is, it is to predict what kind of processing the signal input from the input terminal will receive and how it will be output, and determine the test standard value.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a method for automatically creating an integrated circuit test program by a computer.

[0007]

In order to achieve the above object, an automatic integrated circuit test program creating method according to the present invention comprises the steps of inputting a circuit diagram of an integrated circuit, input terminal names, and output terminal names .
A first step of capturing as input data,
List of combinations of input terminals and output terminals from the circuit diagram
A second step of creating a combination, and each set of the combination list
Set the input conditions of the input terminals for each
Circuit simulation using the
A third step of obtaining an output value (voltage value or current value)
Test conditions based on the results of the circuit simulation.
Test program automatic creation method that automatically sets
The output value is obtained from the result of the first circuit simulation.
Detects two input conditions corresponding to the part where the value changes greatly
And input and output conditions of the two points are set as a start point and an end point.
Of the input condition divided again at a predetermined pitch within the range
Execute the circuit simulation of No. 2 and change the output value
Find the midpoint of the minute and output values within a certain range on both sides of the midpoint.
And a fifth step of obtaining a range of input conditions corresponding to the above .

[0008]

According to the present invention, with the above-described configuration, a list of each terminal is automatically generated , a circuit simulation is executed, and an output value
Finds the midpoint of the part where fluctuates and varies around it
A test that asks for the range of input conditions and sets the input conditions
Because the program is automatically generated, are those that can not Succoth a mistake by human hand.

[0009]

FIG. 1 is a process diagram showing an overall flow of an embodiment of the present invention, and FIG. 2 is a process diagram showing a flow of a circuit simulation portion of an embodiment of the present invention.

An embodiment of the present invention will be described below with reference to FIGS. In FIG. 1, reference numeral 1 denotes a circuit diagram of an integrated circuit, input terminal names,
In the step of taking in the output terminal name and the control terminal name, in the example of FIG. 1, the second terminal, the third terminal are the input terminal names, the twelfth terminal is the output terminal name, the tenth terminal, and the eleventh terminal are the control terminal names. is there. Step 2 is a step of automatically creating a combination list of input terminal names, output terminal names, and control terminal names based on the connection relationship of the circuit diagram based on these input data. In this example, one output terminal and a plurality of control terminals can be simultaneously defined for one input terminal. The control terminal voltage or control terminal current has representative values 0 (V) and 0 (A), respectively, but the representative values can be manually corrected.

Next, reference numeral 3 denotes a circuit simulation step. The input of the circuit simulation is first determined for both the voltage input and the current input to the input terminals of the circuit diagram within a predetermined range of predetermined values. It is assumed that the number of inputs has been changed.

Step 4 is a step of determining test conditions and test standard values based on the results of the circuit simulation.

[0013] In FIG. 2, 5 and 10 divided in the range up to the positive supply voltage VCC = 10 negative supply voltage 0 voltage V ₁₀ from (V) of the voltage V ₇ the input voltage of pin 2 (V) 1 A circuit simulation was performed under one input voltage condition, and 12
Obtaining the output voltage of the turn terminals. Based on the results
Graph of a relationship of a force and output voltage, the input voltage of the two points corresponds to the portion where the output voltage is largely changed (in Figure 2
Step corresponds to the voltage V ₈ and the voltage V ₉ in 5) Ru Step der detected. 6 is a process for increasing the measurement resolution of the further output voltage, re 11 points to 10 divide the range of the start point and the end point of the input voltage of the voltage V ₈ and V ₉ 2 Pin
Run the fine circuit simulation, the output voltage of the 12th pin is determined Umate graph, the range of the output voltage of each 3-division into both sides of the midpoint voltage V ₁₁ of the output voltage changes (output
Voltage V ₁₂ , V ₁₃ ), and the corresponding input voltage
This is a step for obtaining (V ₁₄ , V ₁₆ ) .

In step 6 of FIG. 2, the output voltage V ₁₂ is 4.0
(V), V ₁₃ is 6.0 (V), the corresponding input voltage V ₁₄ is 5.2 (V), V ₁₆ is 5.8 (V). The output voltage is set to a test standard value in consideration of ± 10 (%) as an allowable range. As described above, when 5.2 (V) is input to the second input terminal as shown in step 4 of FIG. 1, the test standard value of the twelfth output terminal becomes 4.0 V of the circuit simulation result. Considering the allowable range ± 10%, the lower limit value is changed from 3.6 (V) to the upper limit value 4.4 (V), and when 5.8 (V) is input to the second input terminal, the twelfth output terminal is used. Similarly, the lower limit of the test standard value is 5.4.
From (V), the upper limit is 6.6 (V).

Similarly, the output voltage or output current of the twelfth output terminal when the input voltage or input current is input to the third input terminal can be obtained, and the test standard value can be obtained.

According to the present invention, when the output value changes,
Find the midpoint of the corresponding input condition, and
To automatically generate a test program that determines the variation range
Quality of can be, integrated circuit by eliminating the mistakes by human hand
Can be improved .

[Brief description of the drawings]

FIG. 1 is a process chart showing the overall flow of an embodiment of the present invention.

FIG. 2 is a process diagram showing a flow of a circuit simulation portion according to one embodiment of the present invention.

[Explanation of symbols]

1 a step of capturing a circuit diagram, input terminal names, output terminal names, and control terminal names 2 a step of automatically generating a list of combinations 3 a step of circuit simulation 4 a step of determining test conditions and test standard values 5 and 6 Process

Claims (1)

(57) [Claims] 1. A first step of taking a circuit diagram of an integrated circuit, an input terminal name, and an output terminal name as input data, and combining an input terminal and an output terminal from the circuit diagram of the input data.
A second step of creating a list so I performs circuit simulation by <br/> computer by setting the input condition of the input terminals of each was the combination of the list was the combination, the
Third to find output value (voltage value or current value) of output terminal
And a step, from the results of the circuit simulation
How to automatically create test programs to automatically set test conditions
The output value is larger than the result of the first circuit simulation.
Detect input conditions of two points corresponding to parts that change sharply
The fourth step, and again within the range where the input conditions of the two points are a start point and an end point
Second circuit simulation of input conditions divided at a predetermined pitch
And calculate the midpoint of the change in the output value.
To obtain output values within a predetermined range on both sides of the midpoint,
A fifth step of obtaining a range of corresponding input conditions .