JP2008299614A - Waveform display method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waveform display method, for reducing the time for displaying simulation waveform or the like of each part obtained in designing a semiconductor integrated circuit on a display device. <P>SOLUTION: The waveform display method for displaying a waveform on a display device comprises the following steps. Waveform data for specifying a waveform is prepared. Waveform data specifying a waveform to be displayed and a resolution of the display device are fetched (S1-S3). By designating a waveform display area, the time corresponding to the X-directional length of the display area is calculated (S4-S5). The calculated display time band is divided to unit times, and the number of waveform data in each divided unit time is counted (S6, S7). Whether the determined number of waveform data corresponds to not less than two dots of a display screen or not (S8). According to the determination result, the waveform is painted out (S9, S10). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a waveform display method for displaying a waveform on a display device, for example, a waveform display method applied to display of a simulation waveform of each part obtained at the time of designing a semiconductor integrated circuit (LSI).

In designing a semiconductor integrated circuit, a timing simulation, a logic simulation, and the like are performed, and it is necessary to display the waveform of each part indicating the result of the simulation on the display screen of the display device.
FIG. 5 shows a display example in which such simulation result waveforms a and b are displayed on the display screen 2 of the display device 1. The display example of FIG. 5 is a case where a part of the waveforms a and b is displayed (enlarged display) on the display screen 2, and the display range of the waveforms a and b is narrow because the time axis is small. For this reason, in the display example of FIG. 5, the entire waveforms a and b cannot be grasped. Therefore, when the display range of the waveforms a and b is widened by widening the time axis, the display example is as shown in FIG.

FIG. 7 shows an enlarged view of a part A of the display example of FIG. FIG. 7A shows a waveform that is actually desired to be displayed on the display screen. FIG. 7B shows the resolution (circle) of the display screen corresponding to the waveform and the waveform display state (black portion of the circle).
A part B of the waveform in FIG. 7A consists of five straight lines as shown, and the following processing is performed to display these five straight lines. That is, the software (program) performs a process of calculating the coordinates that cannot be actually displayed and the display command displayed by the display device for the vertical four-dot area indicated by the display area C a plurality of times. An example of this display command is shown in FIG. 8, and a program of 5 lines is required to display 5 straight lines. The above processing takes time in proportion to the increase in the waveform to be processed.

  As described above, according to the conventional method, when a waveform is displayed on the display screen of the display device 1, the waveform may not be displayed faithfully on the display screen from the viewpoint of the resolution of the display device 1. The same display processing as when displaying is required. For this reason, in the conventional method, there is a problem that it takes time to display a waveform on the display screen as a result of useless processing and time for the display processing.

By the way, as an invention related (similar) to the waveform display method of the present invention, the invention described in Patent Document 1 is known.
In the invention described in Patent Document 1, the original graphic data to be drawn is used as graphic map information for each small area divided into a predetermined size, and when the drawing is actually performed on the display device in consideration of the resolution of the display device. Any drawing of omission drawing (painting), partial omission drawing, or original drawing is performed.
JP 2003-67662 A

However, in the invention described in Patent Document 1, since the display target on the display device is a complex figure including curves, such as various circuits in LSI circuit design, the display of waveforms such as simulation results as described above It is not always appropriate to apply to the method.
In the invention described in Patent Document 1, when drawing is actually performed on the display device, any one of omission drawing (filling), partial omission drawing, and original drawing is performed. It is not necessarily appropriate to apply to a method of displaying a waveform such as a result.
Therefore, in view of the above points, an object of the present invention is to display a waveform that shortens the display processing time when displaying a simulation waveform or the like of each part obtained when designing a semiconductor integrated circuit on a display device. It is to provide a method.

In order to solve the above problems and achieve the object of the present invention, each invention has the following configuration.
A first aspect of the present invention is a waveform display method for displaying a waveform on a display device, the first step of preparing predetermined data in advance as waveform data for specifying the waveform, and a waveform on the display device Prior to display, a second step for obtaining a comparison value for comparison with the resolution of the display device based on the predetermined data, and a third step for comparing the obtained comparison value with the resolution of the display device. When the waveform specified by the waveform data is displayed on the display device, the waveform filling process is performed according to the comparison result of the third step or the filling process is not performed. ,including.

  A second invention is a waveform display method for displaying a waveform on a display device, and a plurality of change point data indicating a change point on the time axis of the waveform is prepared in advance as waveform data for specifying the waveform. A first step, a second step for determining the number of change point data within a unit time determined on the basis of display designation prior to displaying the waveform on the display device; The third step of comparing the number of data with a predetermined value determined in advance based on the resolution of the display device, and the comparison result of the third step when displaying the waveform specified by the waveform data on the display device And a fourth step of performing the waveform filling process or not performing the filling process.

According to a third invention, in the first or second invention, the waveform is a simulation waveform of each part of the circuit obtained at the time of designing a semiconductor integrated circuit.
In a fourth aspect based on the first aspect or the second aspect, the waveform is a pulse waveform, and the change point data of the pulse waveform is a rise time and a fall time of the pulse waveform.
According to the present invention as described above, for example, when displaying the simulation waveform of each part of the circuit obtained when designing the semiconductor integrated circuit on the display device, useless processing can be omitted, so that the display processing time can be shortened.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the embodiment of the waveform display method of the present invention, as a display target, for example, a simulation waveform of each part of a circuit obtained at the time of designing a semiconductor integrated circuit is used, and when the waveform is displayed on a display screen of a display device, FIG. A series of processing as shown is performed using a computer. 1 is stored in advance in a computer memory.
Next, the processing procedure will be described with reference to FIG.
In this example, a plurality of pulse waves, which are simulation waveforms, are displayed on the display screen of the display device. Prior to the display, the plurality of pulse waves are preliminarily stored with waveform data for identifying the pulse wave for each pulse wave. Have it ready. The waveform data is useful for specifying a waveform and is useful for displaying the waveform on a display screen.

FIG. 2 shows an example of a pulse wave to be displayed and its waveform data.
As shown in FIG. 3, the waveform data shown in FIG. 2B uses “time” and “signal value” and is stored in advance in a chain or continuously in the memory. A series of a plurality of waveform data shown in FIG. 3 is stored in the memory for each pulse wave to be displayed.
The above “time” is the time (time) when the amplitude value of the pulse wave changes. The “signal value” is an amplitude value of a pulse wave, and consists of “1” indicating the H level or “0” indicating the L level.

  The pulse wave shown in FIG. 2A is specified by the waveform data shown in FIG. For example, the first pulse wave includes the first waveform data having “time” of “80 ns” and “signal value” of “1”, and the second waveform of “time” of “100 ns” and “signal value” of “0”. Identified by waveform data. Accordingly, it can be said that the first waveform data indicates the rising time of the pulse wave, and the second waveform data indicates the falling time of the pulse wave. For this reason, the first pulse wave rises at 80 ns and falls at 100 ns, as shown.

In this embodiment, the waveform data for specifying the pulse wave is prepared in advance as described above, and in step S1, the waveform data of the pulse wave to be displayed is captured by the computer. In step S2, a predetermined waveform database is created based on the acquired waveform data.
In step S3, the resolution of the display device on which the pulse wave is displayed is captured. The resolution is the size of dots (pixels) on the display screen of the display device, and differs depending on the display capability.

Next, when the operator designates (sets) a display area on the display screen of the display device on which the pulse wave is displayed, the length (width) in the X direction (lateral direction) of the display area is designated ( Step S4). In step S5, a time corresponding to the designated width is calculated.
Here, the indication of the display area of the pulse waveform on the display screen may be a part of the display screen or the entire display screen.

In step S6, the calculated display time width is divided into unit times. In step S7, the number of pulse wave waveform data (see FIG. 2B) within the unit time is counted for each unit time. That is, this corresponds to counting the number of change points of pulse waves within a unit time.
Here, the unit time is the time corresponding to the unit length in the X direction of the designated display area (for example, the length of 2 dots on the display screen), and the display captured in step S3. Determined with reference to the resolution of the device. Accordingly, obtaining the number of waveform data of pulse waves within a unit time is equivalent to counting the number of straight lines in the Y direction (vertical direction) to be displayed within the range of two dots in the X direction on the display screen. To do.

In step S8, it is determined whether or not the number of waveform data of the pulse wave within the unit time obtained in step S7 is equal to or more than two dots on the display screen of the display device.
Here, the reason why the criterion is set to two dots (pixels) on the display screen is that there is no practical problem.
In step S8, when the number of change points of the pulse wave within the unit time is equal to or more than two dots on the display screen (positive determination), the pulse wave is displayed in a filled state when displayed on the display screen. In order to do this, a filling process is performed by designating a range (step S9).

Here, an example of the display command for the painting process with the range designation is as shown in FIG. This example is a display command necessary to display 4 × 5 dots, and a four-line program is sufficient.
In step S11, based on the processing result, the pulse wave is displayed on the display screen in a painted state.

On the other hand, in step S8, when the number of change points of the pulse wave within the unit time is equal to or less than two dots on the display screen (negative determination), the waveform drawing coordinates are displayed in order to display the pulse wave as it is. Calculation is performed (step S10). In step S11, the pulse wave is displayed on the display screen without being filled based on the processing result.
As described above, according to this embodiment, when displaying a simulation waveform of each part obtained at the time of designing a semiconductor integrated circuit on a display device, useless processing can be omitted and display processing time is shortened. be able to.

In the embodiment, the pulse wave is displayed as an example of the display waveform. However, the display target is not limited to this, and there is a certain regularity, and waveform data is created in advance by using the regularity. I hope I can.
Therefore, in the present invention, a sawtooth wave or a triangular wave (ramp wave) may be used instead of the pulse wave. For example, in the case of a sawtooth wave, the waveform data specifying the waveform is basically the same as the waveform data of the pulse wave.

It is a flowchart which shows the process sequence of embodiment of this invention. It is explanatory drawing which shows the relationship between the pulse wave which is going to be displayed, and the waveform data which identify it. It is a figure which shows an example of a series of waveform data which specify a pulse signal. It is a figure which shows an example of the display command in the case of a painting process. It is a figure which shows the example of a display of the conventional display apparatus. It is a figure which shows the example of a display at the time of displaying the whole waveform of FIG. It is the enlarged view to which a part of display waveform of FIG. 6 was expanded. It is a figure which shows an example of the conventional display command.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Display apparatus, 2 ... Display screen, a, b ... Pulse wave (display waveform)

Claims (4)

A waveform display method for displaying a waveform on a display device,
A first step of preparing predetermined data in advance as waveform data for specifying the waveform;
Prior to displaying a waveform on the display device, a second step of obtaining a comparison value for comparison with the resolution of the display device based on the predetermined data;
A third step of comparing the obtained comparison value with the resolution of the display device;
When displaying the waveform specified by the waveform data on the display device, according to the comparison result of the third step, the waveform filling process is performed, or the filling process is not performed fourth step,
A method for displaying a waveform, comprising: A waveform display method for displaying a waveform on a display device,
A first step of preparing in advance a plurality of change point data indicating change points on the time axis of the waveform as waveform data for specifying the waveform;
Prior to displaying the waveform on the display device, a second step of determining the number of change point data within a unit time determined based on display designation;
A third step of comparing the obtained number of change point data with a predetermined value based on the resolution of the display device;
When displaying the waveform specified by the waveform data on the display device, according to the comparison result of the third step, the waveform filling process is performed, or the filling process is not performed fourth step,
A method for displaying a waveform, comprising:   3. The waveform display method according to claim 1, wherein the waveform is a simulation waveform of each part of the circuit obtained when designing a semiconductor integrated circuit.   The waveform display method according to claim 1, wherein the waveform is a pulse waveform, and the change point data of the pulse waveform is a rise time and a fall time of the pulse waveform.

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