JPH04190459A - Simulation device - Google Patents

Abstract

PURPOSE:To improve design efficiency by automatically extracting a feature value from the result of the simulation of circuit operation based upon various inputted simulation conditions, and comparing its expected value with the feature value and automatically deciding whether the extracted values are normal or not. CONSTITUTION:An output voltage VOUT is extracted as the feature value of the simulation execution result obtained by varying, for example, a set voltage VCC and an input voltage VIN as parameters. In this case, a characteristic value extraction information part 5 is so set that the VOUT is extracted. A digital signal conversion information holding part 7 is stored with information for converting the VOUT into three values of '0', '1', and '2'. For example, when VCC = 5V and VIN = 3V, an expected value '1' is outputted from an expected value holding part 9 when the VOUT is 2.3 - 2.5V, a decision showing that the extracted value is normal with this parameter combination is stored in a decision result storage part 11, and the result is outputted graphically on a display part 13, thereby clearly deciding at a glance that 'o' are normal values and 'x' and values outside a normal range.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a simulation apparatus that executes simulations such as circuit simulation, timing simulation, logic simulation, etc. using circuit connection information and simulation conditions as input data.

[Conventional technology]

When designing an electronic circuit, its operation is usually verified in advance through various simulations such as circuit simulation, logic simulation, and timing simulation.

Circuit simulation is performed at the time of circuit design, using circuit connection information and simulation conditions as input data for circuit operating conditions, in order to determine whether or not the value (characteristic value) at each observation point is within a normal range with respect to an input signal. In addition, logic simulation verifies the logic of the designed circuit, and timing simulation verifies whether the signal propagation delay satisfies specified specifications.

FIG. 6 is a block diagram showing the configuration of a conventional circuit simulation device. In the figure, 1 is a circuit connection information holding unit that holds circuit connection information indicating the connection relationship of each element constituting the circuit, and the circuit connection information held in the holding unit 1 is held in a simulation condition holding unit 2. It is given to the circuit simulation execution unit 3 as input data together with the simulation conditions. Here, the simulation conditions are data such as characteristics of each element and input conditions to the circuit. The circuit simulation execution section 3 executes a circuit simulation based on input data, and the execution result is held in the simulation execution result holding section 4. Then, the held execution results are displayed in graph ink on the display section 13 by the graph ink output section 12. Then, the operator reads the characteristic value based on the displayed execution result and determines whether it is normal or not.

[Problems to be Solved by the Invention] Since the conventional circuit simulation device is configured as described above, it is possible to change at least one of circuit connection information and circuit operation conditions such as simulation conditions as a parameter through circuit simulation. When checking whether the output characteristic value as the result of a simulation is within a certain normal range, it is necessary to read the characteristic value from the simulation execution result and determine whether the read characteristic value is within the normal range. Everything had to be done manually, and the graphing of the judgment results to clarify the distribution of normal values was also done manually. Therefore, design efficiency decreases,
There was a problem in that it took a long time to design.

The present invention has been made in view of the above circumstances, and it extracts characteristic values from simulation results, determines whether the characteristic values are expected values, and retains the determination results, thereby making it easier to operate manually. It is an object of the present invention to provide a simulation device capable of extracting and discriminating characteristic values without any trouble, and displaying the retained discrimination results in graphic ink.

[Means to solve the problem]

The simulation device according to the present invention extracts one value as a characteristic value from a plurality of simulation execution results that are changed using at least one of the input data as a parameter, and extracts the extracted value and its expected value. The extracted values are compared to determine whether the extracted values are good or bad, and the determination results are stored in association with the parameters.

[Effect]

In the present invention, simulations are sequentially executed by changing at least one of the input data as a parameter,
One value is extracted as a characteristic value from the execution result, the extracted value is compared with its expected value to determine whether the extracted value is good or bad, and the determination result is stored in association with the parameter. Therefore, extraction and discrimination of characteristic values can be performed without manual intervention, and graph display can also be automated by displaying them on a display using values stored in association with parameters.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on drawings showing embodiments thereof. FIG. 1 is a block diagram showing the configuration of a circuit simulation device which is a simulation device according to the present invention. In the figure, 1 is a circuit connection information holding unit that holds circuit connection information indicating the connection relationship of each element constituting the circuit, and the circuit connection information held in the holding unit 1 is held in a simulation condition holding unit 2. It is given to the circuit simulation execution unit 3 as input data together with the simulation conditions. Here, the simulation conditions are data such as characteristics of each element, input conditions to the circuit, etc., and also include information or conditions used as parameters and their values. The circuit simulation execution section 3 executes a circuit simulation based on the input data, and provides the execution result to the simulation execution result holding section 4. The simulation execution result holding unit 4 holds the execution results and provides the held execution results to a graph ink output unit 12 or a characteristic value extraction unit 6, which will be described later. The characteristic value extraction unit 6 extracts characteristic values from the execution results based on the characteristic value extraction information stored in the characteristic value extraction information holding unit 5 and determines what kind of characteristic values are to be extracted from the execution results, and extracts the characteristic values from the execution results. The value is given to the digital signal converter. The digital signal conversion unit 8 converts the characteristic value extracted according to the digital signal information held in the digital signal information holding unit 7 into digital multi-value data, and provides the converted multi-value data to the discrimination unit 10. The determining unit 10 compares the expected value corresponding to the extracted characteristic value held in the expected value holding unit 9 with the characteristic value, determines whether the characteristic value is within the normal range, and uses the determination result as the determination result. It is given to the storage unit 11.

The determination result storage unit 11 stores the determination results in association with the parameter values at the time of simulation execution, and provides them to the graphic output unit 12. The graphic output unit 12 causes the display unit 13 to graphically output the simulation execution result or the determination result held in the determination result storage unit 11.

Next, the operation will be described using an example in which the circuit simulation apparatus extracts the output voltage VOUT as a characteristic value of the circuit simulation execution result when the voltage VCC and the input voltage VIN are changed as parameters among the simulation conditions.

FIG. 2 is a flowchart explaining the simulation procedure. In this case, characteristic value extraction information is set in the characteristic value extraction information holding section 5 so that the output voltage VOUT is extracted as a characteristic value. Further, the digital signal information holding section 7 has an output voltage VOU according to the combination of parameters.
Digital signalization information for converting T into ternary digital data of "0", "1", and "2" is stored.

FIG. 3 is a diagram showing an example of digital signalized information, and shows, for example, the relationship between the output voltage VOUT and digital ternary data when the voltage VCC=5V and the input voltage VIN=3V. Further, the expected value holding unit 9 holds "B" as an expected value.

First, according to the parameter value combination A (VCC=5V, VIN=3V) preset in the simulation conditions held in the simulation condition holding unit 2,
The circuit simulation execution unit 3 executes a circuit simulation (Sl).

Next, the characteristic value extractor 6 extracts the output voltage VOIJT as a characteristic value according to the characteristic value extraction information (S2), and the extracted characteristic value, that is, the output voltage VOUT, is converted into a digital signal by the digital signal converter 8 according to the digital signal information. For example, as shown in FIG. 3, if the output voltage VOUT is 2.5 cm, the characteristic value is converted to 1".

Next, the characteristic value converted into a digital signal is compared with the expected value by the discriminator 10, and it is determined whether it matches or does not match the expectation (S
4) The determination result is stored in the determination result storage unit 11 in association with the parameter value (S5). For example, if "1" is set as the expected value, the information "rVCC=5V, VIN=3■, normal" is held for the combination A.

Next, it is determined whether circuit simulation has been performed for all combinations of parameter values (S6).
, if the circuit simulation has not been completed for all, the process returns to step S1; if it has been completed, the graphic output unit 12 graphically outputs the information held in the determination result storage unit 11 to the display unit 13 ( S7
).

FIG. 4 is a diagram showing an example of display on the display unit 13, in which the determination results are displayed in a graph. This graph shows the voltage V on the vertical axis.
CC is plotted, and the input voltage VIN is plotted on the horizontal axis, and the coordinates of the intersections in the graph indicate combinations of parameter values. - Also, the ○ displayed at the intersection indicates that the output voltage VOUT, that is, the characteristic value is within the normal range. In addition, × indicates that it is outside the normal range, and thereby the characteristic value can be clearly determined at a glance.

Next, other embodiments of the present invention will be described. In the embodiment described above, the determination results are held every time a simulation is executed, and then it is determined whether or not all simulations are completed. However, in this embodiment, characteristic values are extracted after simulations of all combinations are executed.

FIG. 5 is a flowchart showing the simulation procedure of the circuit simulation device according to another embodiment, in which simulations are first executed for all parameter combinations (Sll, 512), and after the simulation is completed, they are stored in the simulation execution result holding unit 4. Steps 514 to S1 of extracting characteristic values from the executed results (steps 513), converting them into digital signals, determining them, holding the determined results, and outputting them as graphics
Do step 7.

Although the above two embodiments have been described using a circuit simulation device as an example of a simulation device, the present invention is not limited to this, and the same effect can be obtained even when applied to a timing simulation device or a logic simulation device. Needless to say.

In addition, in the above embodiments, the characteristic values are digitized to determine whether the characteristic values are good or bad, so it is possible to easily determine whether the characteristic values are good or bad by simply comparing the characteristic values with the expected values, and the determination can be made quickly. can be done.

〔Effect of the invention〕

As explained above, according to the present invention, characteristic values are automatically extracted from simulation execution results, and the quality of the extracted values can be automatically determined by comparing the extracted values with their expected values. This eliminates the need for manual labor, improves design efficiency, and achieves the equivalent effect of shortening design time.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a circuit simulation device that is a simulation device according to the present invention, FIG. 2 is a flowchart showing the operation during circuit simulation of the present invention, and FIG. 3 is a diagram showing an example of ternary data. , FIG. 4 is a diagram showing an example of a graph display of the discrimination results, FIG. 5 is a flowchart showing the operation during circuit simulation of another embodiment, and FIG. 6 is a block diagram showing the configuration of a conventional circuit simulation device. be. 1...Circuit connection information holding unit 2...Simulation condition holding unit 3...Circuit simulation execution unit 5
...Characteristic value extraction information holding section 6...Characteristic value extraction section 9
. . . Expected value storage unit 10 . . Discrimination unit 11 . Agent Masu Oiwa 2nd
Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] (1) In a simulation device that executes a circuit operation simulation using circuit connection information indicating the connection relationship of each element in the circuit and simulation conditions including characteristics of each element and input conditions to the circuit as input data, an extraction means for extracting one value from each of the results of a plurality of simulations sequentially executed while changing at least one of them as a parameter; and a comparison between the value extracted by the extraction means and its expected value. A simulation apparatus comprising: means for individually determining whether each extracted value is good or bad; and storage means for sequentially storing the determination results in association with the parameters.