JPH0322087A - Logic simulator - Google Patents

Abstract

PURPOSE:To quickly find a position of erroneous logic by changing the color, the luminance, or the like of a signal line of a logic circuit diagram in accordance with the signal value to display discrimination of the signal value on a display screen. CONSTITUTION:A mechanism 1 which calculates signal values of all signal lines, a converting mechanism which converts each signal line to color or luminance data in accordance with its signal value, and a mechanism 3 which displays the signal line on a picture are provided. Results of simulation displayed on the display screen of a display device 3 show that signals simultaneously inputted from input terminal IN1 and IN2 are not simultaneously obtained in output terminals OUT1 and OUT2 because of delay. Thus, a position of erroneous logic is visually and quickly found and a delay element can easily inserted to the position of timing deviation because signal values of all signal lines are displayed with colors or luminances of signals, and it is unnecessary to allow signal lines and output patterns changing on them to correspond to each other because signal values are expressed with signal lines themselves. Thus, the time is shortened and the work is simplified in the logic simulation process.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a logic simulator.

[Conventional technology]

In conventional logic simulation systems, the values of signals at human output terminals and some observation points are expressed by combinations of time and signal values in a pattern or logical values as shown in the display diagram of FIG. 4.

[Problem to be solved by the invention]

The conventional logic simulators mentioned above cannot see changes in signal values and logic circuit diagrams at the same time, so it takes time to discover logic errors, and test patterns or logic values and the logic in which they appear There were two drawbacks: it was not easy to check the position on the circuit diagram.

[Means to solve the problem]

The signal value identification and display type logic simulator of the present invention has a mechanism for calculating logical values, a mechanism for converting the logical values into signal line color or brightness data, and a mechanism for displaying the signal lines on the screen. It is structured as follows.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of an example of the present invention.

The signal value identification and display type logic simulator has a mechanism 1 for calculating the signal values of all signal lines, a mechanism 2 for converting the signal values into signal line color or luminance data, and a mechanism 3 for displaying the signal lines on the screen. are doing.

FIG. 2 is a display diagram of the simulation results drawn on the display screen of block display 3 in FIG.

It can be seen that the signals inputted at the same time from the input terminals INI and IN2 are not obtained at the same time at the output side UTI and OUT2 due to a delay.

FIG. 3 is a display diagram according to the present invention corresponding to the display diagram of the conventional logic simulator of FIG. 4.

On the output result screen in Figure 4, it was necessary to compare the logic circuit diagram and the timing chart, but in this third embodiment, the color or brightness of the signal line changes over time, so it is easy and reliable to compare the signal line. You can check the value.

〔Effect of the invention〕

As explained above, the present invention displays the signal values of all signal lines using the color and brightness of the signal, so that it is possible to quickly and visually detect faulty logic, and to correct timing deviations. The above two points are that delay elements can be easily inserted, and since the signal value is expressed by the signal line itself, there is no need to correspond between the signal line and the output pattern that changes on it. This has the effect of shortening the simulation process time and simplifying the work.

[Brief Description of the Drawings] Figure 1 is a block diagram of an embodiment of the present invention, Figures 2 and 3 are illustrations of Figure 1, and Figure 4 is an illustration of an example of a conventional logic simulator. be. l...Calculation of signal values of all signal lines, 2...
・Conversion from signal value to signal line color or brightness data,
3...Display the signal line on the screen.

Claims (1)

[Claims] A logic simulator characterized by displaying signal value identification on a display screen by changing the color, brightness, etc. of signal lines in a logic circuit diagram depending on the signal value.