JPH0415757A - Method for controlling simulation output - Google Patents

Abstract

PURPOSE:To delete the results of observation obtained in an undesired period by controlling the working of an output control circuit with an observation control signal and outputting the result of the simulation observation in an optional period. CONSTITUTION:A simulation circuit 1 simulates a logic circuit. At the same time, an output control circuit 2 turns on or off the output of an observing point for the simulation result of the circuit 1. The working of the circuit 2 is controlled by an observation control signal. As a result, the result of the simulation observation can be outputted in an optional period. Thus it is possible to prevent the reduction of the simulating speed owing to the shortage of storage capacity of a simulator or a long period of time needed for the processing of the simulation result.

Description

[Detailed description of the invention] 〔overview〕 Long hours in logic circuit simulation.

Regarding a simulation output control method that enables high-speed simulation, we developed a simulation output control method that allows the simulation circuit to externally control the output of simulation results at observation points, and thereby enables deletion of observation results from unnecessary periods. In a simulation circuit that simulates a logic circuit, an output control circuit is provided to connect and disconnect the output of an observation point where simulation results are observed, and the operation of this output control circuit is controlled by an observation control signal. By,
It is constructed by making it possible to output simulation observation results for any period of time.

[Industrial application field]

The present invention relates to a method for controlling the output of simulation results in logic circuit simulation, and particularly to a simulation output control method that enables long-time, high-speed simulation.

Digital systems are required to have higher functionality and to be developed in a short period of time. In order to meet these demands, it is necessary to perform system-wide logic simulation as a functional verification tool for digital system design.
Therefore, it is required to be able to perform large-scale, long-term, high-speed simulations.

In such logic circuit simulations, it is desired that by suppressing the output of unnecessary simulation results, simulations can be performed for a long time, and the simulations can be executed at high speed.

[Conventional technology]

Conventionally, as a simulation output control method for a logic circuit that is capable of long-time, high-speed simulation, there is a method that uses a simulator that has hardware that can perform logic circuit simulation at high speed.

However, in such conventional methods, observation points for simulation results are set before the start of the simulation and cannot be changed during execution of the simulation.

FIG. 4 shows a conventional simulation output control method, in which numeral 11 indicates a simulation circuit;
12 is a logic circuit (Sl) consisting of an AND circuit, 13 is a logic circuit (S2) consisting of an OR circuit, and 14 is an observation point.

In the circuit shown in FIG. 4, the logic circuit (Sl) 12 performs an AND operation on inputs A and B to generate an output, and the logic circuit (32) 13 operates on the logic circuit (SL) 12. A logical OR operation is performed on the output of and the input C to generate an output O. A signal resulting from the simulation in the simulation circuit 11 is taken out from an observation point 14 provided at the output of the logic circuit (SL) 12 and recorded in a simulator (not shown).

In this way, in conventional simulation circuits, the observation point for simulation results is set before the simulation starts and cannot be changed during simulation execution, so the simulator records the observation results at this observation point for the entire simulation time. It looks like this.

[Problem to be solved by the invention]

A conventional simulation output control method records the observation results of the simulation at observation points set before the start of the simulation for the entire simulation time. Therefore, since the storage capacity is limited, the time during which simulation can be performed is limited, and the simulation speed is reduced due to processing of simulation results.

The present invention is an attempt to solve the problems of the prior art, by adding a circuit for controlling the observation operation of the observation point and a control signal for this control to the simulation circuit. The purpose of this invention is to provide a simulation output control method that allows the output of point simulation results to be externally controlled, thereby making it possible to delete observation results of unnecessary periods such as system initialization in system simulation. It is said that

[Means for Solving the Problems] As shown in the principle configuration of the present invention in FIG. By enabling the output to be communicated and controlling the operation of the output control circuit 2 using an observation control signal, simulation observation results can be output for any period of time.

In this case, the output control circuit 2 is constituted by a switch 3 whose on/off is controlled by an observation control signal.

[Function] The simulation circuit 1 simulates a logic circuit. The output control circuit 2 connects or disconnects the output of an observation point for observing simulation results in the simulation circuit 1, and the operation of the output control circuit 2 is controlled by an observation control signal. Therefore, simulation observation results can be output for any period of time, which prevents the simulator from running out of storage capacity or requiring a long time to process simulation results, which slows down the simulation speed. Prevented.

In this case, the output control circuit 2 directly outputs the simulation results at the observation point by turning on and off the switch 3 using the observation control signal.

[Example] FIG. 2 shows an example of the present invention.
The same parts as in the figure are indicated by the same numbers, 15 is the output control circuit, 16 is a switch provided in the output control circuit 15, 17 is the output of the switch 16, and 18 is the output control circuit 15.
This is the observation control signal for

In the circuit of the embodiment shown in FIG. 2, an output control circuit 15 and an observation control signal 18 are added to the simulation circuit 11, so that the output 17 of the switch 16 is adjusted according to the simulation result during simulation. Operate as an observation point.

The switch 16 is turned on and off according to the observation control signal 18, so that the output control circuit 15 transmits or not transmits the signal of the simulation result at the observation point 14 to a simulator (not shown).

Therefore, according to the embodiment shown in FIG. 2, the output of simulation results in the simulation circuit is controlled by the observation control signal, and only the simulation results for a necessary part of the time are transmitted to the observation point and output. .

When processing simulation results at the time of signal change, the simulation results during the period in which the output is suppressed will be a constant value (for example, undefined), and the contents that have changed during this period will not be processed as simulation results.

FIG. 3 shows an example of application of the present invention to a system, where 21 is a circuit information file that describes simulation circuit information, 22 is an observation control data file that describes observation control data, and 23 is test data. 24 is an observation point specification file in which data for specifying observation points is written. 25 is an output control circuit addition program that adds an output control circuit to the simulation circuit; 26 is an observation control signal addition function program that adds an observation control signal along with the addition of the output control circuit; and 27 is an output control circuit addition program. This is an observation point change program that changes observation points accordingly. 28 is a circuit information file that describes circuit information to which an output control circuit is added;
Reference numeral 29 is a test data file in which test data to which an observation control signal has been added is written, and 30 is an observation point specification file in which changed observation point specification data is written. Reference numeral 31 indicates a simulation function, and reference numeral 32 indicates a simulation result file for recording simulation results.

When performing a simulation, information on the simulation circuit is stored in the circuit information file 21, information on which of the observation points in the simulation circuit should be observed and from when to when to be observed is stored in the observation control data file 22, and the information for testing the simulation circuit is stored in the observation control data file 22. Input data is stored in the test data file 23, and data indicating each observation point specified in the simulation circuit is stored in the observation point specification file 2.
4. Create each.

A program 25 that realizes the function of adding the output control circuit of the present invention to these data, a program 26 that realizes the function of adding an observation control signal along with the addition of the output control circuit, and the addition of the output control circuit. A program 27 is provided that realizes a function of changing the observation point in accordance with the change in observation point.

By executing these programs, a circuit information file 28 with an output control circuit added, a test data file 29 with an observation control signal added, and an observation point specification file 30 with changed observation points are created. Therefore, a simulation result file 32 is obtained by performing the simulation shown in 31 using this information and recording data of the obtained simulation result in the simulator. By comparing the simulation results obtained in this way with data prepared in advance, it is verified whether the function of the logic circuit is as predicted.

In the application example shown in Figure 3, when performing a simulation, the observation point whose output is to be controlled among the observation points, its observation time, etc. are created as observation control data, and an output control circuit is added. By programming the function, @蛯 for adding an observation control signal, and the function for changing the observation point, it is possible to easily obtain the output of the simulation result at the required point in time at the observation point.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to suppress the output of unnecessary simulation results, and in the same system, the amount of data of simulation results is reduced, making it possible to perform simulations over a longer period of time. . At the same time, by reducing the amount of processing required to output the simulation results, the simulation can be executed faster.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the basic configuration of the present invention, FIG. 2 is a diagram showing an embodiment of the present invention, FIG. 3 is a diagram showing an example of application of the present invention to a system, and FIG. 4 is a diagram showing a conventional system. FIG. 3 is a diagram showing a simulation output control method. 1 is a simulation circuit, 2 is an output control circuit, and 3 is a switch.

Claims (2)

[Claims] (1) In the simulation circuit (1) that simulates a logic circuit, an output control circuit (2) is provided to disconnect or disconnect the output of an observation point for observing simulation results, and the operation of the output control circuit (2) is observationally controlled. A simulation output control method characterized in that simulation observation results can be output for any period of time by controlling using signals. (2) The simulation output control method according to claim 1, wherein the output control circuit (2) comprises a switch (3) whose on/off is controlled by an observation control signal.