JP2605932B2 - Layout design equipment for semiconductor integrated circuits - Google Patents

Description

The present invention relates to a layout design apparatus for a semiconductor integrated circuit (IC), and more particularly to an IC layout design apparatus using a layout CAD.

2. Description of the Related Art Conventionally, in the layout design of a semiconductor integrated circuit of this type, an element such as a transistor and a resistor, or an arrangement of a block constituted by these elements is determined in accordance with a result of the circuit design.

This layout design is performed using, for example, an engineering workstation (EWS).
, For example, interactively while displaying the layout of the circuit pattern on the monitor screen.

In this case, in the EWS, for example, a schematic editor (DASH or the like) is used to perform from the input of the logic circuit diagram to the logic simulation. In addition, the unit function block is divided into units to be laid out from the logic circuit diagram, and the size of the layout block is roughly estimated. The layout of power supply lines, clock lines, data buses, and the like and the positions of pads are examined in units of blocks, and finally, the arrangement of each block and wiring between blocks are performed.

<Problems to be Solved by the Invention> However, such a conventional IC layout design apparatus performs the above-described layout design work while displaying a layout of an actual circuit pattern of the IC on a monitor screen by layout CAD. . In this case, the actual circuit pattern displayed on the monitor screen has a plurality of layers of wirings, elements, and the like, which are complicated, and have a problem that it is difficult for an operator to understand and distinguish.

<Object of the Invention> Accordingly, an object of the present invention is to provide a layout design apparatus for a semiconductor integrated circuit in which a part of a circuit pattern is clearly displayed on a monia screen in an LSI layout design. It is.

<Means for Solving the Problems> According to the present invention, as shown in FIG. 1, a layout of a circuit pattern is displayed on a monitor screen in a semiconductor integrated circuit formed by combining a plurality of logic gates. In the semiconductor integrated circuit layout design apparatus capable of editing the circuit pattern above, a pattern storage means 100 for holding in a table circuit patterns of a plurality of logic gates whose equivalence with the logic gate has been verified, Specifying means 200 for specifying a gate, extracting means 300 for extracting the circuit pattern of the specified logic gate from the table, and searching and specifying all layout diagrams of the semiconductor integrated circuit displayed on the monitor screen Replace the replaced logic gate circuit pattern with the extracted logic gate circuit pattern, and replace And a display change means 400 for displaying the display in a manner different from that shown in the figure.

<Operation> With the layout design apparatus for a semiconductor integrated circuit according to the present invention, the layout of the circuit pattern of the semiconductor integrated circuit can be displayed on a monitor screen, and the circuit pattern can be edited on the monitor screen. For example, a layout CAD is used.

In this case, in the present apparatus, the pattern storage means 100
Holds in a table the circuit pattern whose equivalence with the logic gate has been verified.

Therefore, when a logic gate having a specific function is designated by the designation means 200, the extraction means 300 extracts the circuit pattern of the designated logic gate from the table. Further, the display changing means 400 searches the layout diagram of all the circuit patterns of the semiconductor integrated circuit displayed on the monitor screen, and replaces the designated logic gate circuit pattern with the extracted logic gate circuit pattern. indicate. The display in this case is a display different from the circuit pattern that has not been replaced, for example, a change in displayed color. Highlighting such as blinking of that portion is performed.

That is, in the present invention, a specific functional part in the layout drawing of the circuit pattern can be displayed on the monitor screen so as to be different from other parts, and correction and cutout (separation) can be easily performed on the monitor screen. What can be done.

Hereinafter, an embodiment of a layout design apparatus for a semiconductor integrated circuit according to the present invention will be described with reference to the drawings.

 2 to 4 are views showing an embodiment of the present invention.

FIG. 2 shows a system configuration of a CAD system according to the present invention.

As shown in FIG. 1, the system comprises a central processing unit comprising a minicomputer 11, a magnetic tape device 12 (corresponding to a pattern storage means) for storing and holding circuit pattern data, and a magnetic disk device 13 for storing data. , A digitizer 14 for inputting position information of a circuit pattern and the like, and a monitor display 15 for displaying input figures. In addition to the digital plotter 17 for drawing circuit patterns,
8. It has a line printer 19. 16 is monitor 1
Input device to 5, such as a light pen or a mouse. Reference numeral 20 denotes a command menu display section of the digitizer 14.

FIG. 3 is a block diagram showing the layout design apparatus in more detail.

That is, the CPU 21 is connected to the following devices via a bus line.

For example, CRT15 is a video display controller VDP23
Connected to the bus line. This VDP23 is VRA
Control is performed when the data stored in M24 is displayed on CRT15.

25 is a keyboard and a keyboard interface 26
Is connected to the CPU 21 via the.

27 indicates a plotter and 28 indicates its interface.

Reference numeral 29 denotes an interface of the magnetic disk drive 13, and reference numeral 30 denotes an interface of the magnetic tape drive 12.

As is well known, the CPU 21 has a ROM 31 and a RAM 32 as internal storage devices.

A program executed at the time of layout design by the CPU 21 will be described below with reference to FIG.

As a premise, a program for verifying equivalence with logic circuits
By using the existing schematic CAD output using LVS, for a logic circuit having a specific function, the correspondence between the circuit and the circuit pattern on the monitor display is clarified as a table. This table is stored in the magnetic tape device 12 as a test data library TDL.

Therefore, the logic circuit (for example, NA
The following flow chart shows how to change the color of an ND gate and the like on the monitor screen and display it.

First, for example, an input is scanned from the keyboard 25 or the like (step S401) (S401 corresponds to the specifying means), and the gate number of the specified logical gate is recognized (S402).

Next, the logic gate (NAND, NOR, AND,...) Corresponding to the gate number is read from the table (S403), and the data of the corresponding circuit pattern is read from the table and held in the RAM 32 or the like (S404). (S403 and S404 correspond to the extracting means).

Then, the specified logic gate is scanned for the layout of all circuit patterns displayed on the monitor screen (S405). The coordinate data of the logic gate read by this scan is written to the VRAM 24 (S406). This is the extraction of the specified logic gate.

Next, a color change is instructed in the VRAM 24 for the written data (S407). These steps S405, S40
6, S407 corresponds to a display change unit. For example, the RGB signal is changed by rewriting data. Then, it is checked whether or not the data rewriting for the color change has been completed (S408). When the data rewriting has been completed, the screen display control is transferred to the VDP 23 (S409). Thereafter, the VDP 23 changes the color of the circuit pattern on the monitor screen for this logic gate. Note that only the circuit pattern portion indicating the designated logic gate instead of the color change may be made to blink.

<Effects> As described above, according to the present invention, in the layout design of a semiconductor integrated circuit, a part of the circuit pattern can be displayed on the monitor screen so as to be different from other parts. As a result, for example, it was possible to improve the efficiency of the work of modifying and cutting out a specific logic gate.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a semiconductor integrated circuit layout designing apparatus according to the present invention. FIG. 2 is a conceptual diagram showing a system configuration of a semiconductor integrated circuit layout designing apparatus according to one embodiment of the present invention. FIG. 3 is a block diagram showing a configuration of a semiconductor integrated circuit layout design apparatus according to one embodiment of the present invention, and FIG. 4 is a control by a CPU of a semiconductor integrated circuit layout design apparatus according to one embodiment of the present invention. It is a flowchart which shows a program. 100 ... pattern storage means, 200 ... designation means, 300 ... extraction means, 400 ... display change means.

Continuation of the front page (56) References JP-A-61-228577 (JP, A) JP-A-2-28882 (JP, A) JP-A-57-153443 (JP, A) JP-A-59-180652 (JP) , A) First edition of “Practical ASIC Technology”, edited by Hisashi Sugiyama (1987-5-1). 39-46, p. 60−63

Claims (1)

(57) [Claims] 1. A semiconductor integrated circuit comprising a combination of a plurality of logic gates, wherein a layout of the circuit pattern is displayed on a monitor screen, and the circuit pattern can be edited on the monitor screen. A pattern storage means for holding in a table circuit patterns of a plurality of logic gates whose equivalence with the logic gate has been verified; a designating means for designating a logic gate of a specific function; and a circuit pattern of the designated logic gate. Extracting means for extracting from the table, searching all layout diagrams of the semiconductor integrated circuit displayed on the monitor screen and replacing the circuit pattern of the designated logic gate with the circuit pattern of the extracted logic gate, Display changing means for displaying the replaced portion differently from the display of the non-replaced portion And a layout design apparatus for a semiconductor integrated circuit.