JP2612063B2 - How to display mask layout data - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for displaying mask layout data for efficiently displaying mask layout data of a semiconductor integrated circuit on a device.

[Conventional technology]

In recent years, the degree of integration of semiconductor integrated circuits has been rapidly increasing, and on the other hand, design methods such as a gate array method and a standard cell method have been widely used. As a result, the number of cells (circuit elements having one integrated function such as a multiplication function and an accumulator function) constituting one chip has increased dramatically, leading to an enormous increase and complexity of mask layout data. . Along with this, the load on a processing device such as a CAD (Computer Aided Design) device for creating and displaying mask layout data is increasing. In particular, responsiveness when a part of the mask layout is enlarged and displayed has been reduced.

Hereinafter, a conventional method of displaying mask layout data will be described.

FIG. 2 shows a file structure conventionally used in a processing device such as a CAD device. In FIG. 2, reference numeral 1 denotes a cell name N1 of the arranged cell, and arrangement points L1, L
2. This is a cell structure description file in which a record including various other pointers P1 is stored for a plurality of cells, and FIG. 2 shows the format of one record. Reference numeral 2 denotes a cell-specific information file that stores information such as cell size, and records a record including a cell name N2, information S1 to S4 indicating cell size, and other various information P2 for a plurality of types of cells. Stored. The cell structure description file 1 and the cell specific information file 2 are mutually connected by one pointer P11 of the pointers P1 and a pointer P21 included in the information P2. Reference numeral 3 denotes a mask layout data file storing mask layout data, which is connected to the cell-specific information file 2 by a pointer.

An example of each record of the cell structure description file 1 and the cell specific information file 2 is shown in Tables 1 and 2 below, respectively.

In the cell specific information file 2, the cell size is described by relative coordinate values. The number of data in each of the files 1 and 2 is the number of cell calls in the cell structure description file 1 and the number of cell types in the cell specific information file 2.
For example, while the cell named "CELL-A1" appears three times in the above Table 1 showing the records of the cell structure description file 1, the above Table 2 showing the records of the cell specific information file 2 appears three times. Appears only once.

The flow of processing when displaying mask layout data will be described with reference to FIG. The process is performed by sequentially reading the data of the cell structure description file 1, and the process ends when there is no more data. In step n1, a record of the cell structure description file 1 is read, and a pointer of the cell unique information file 2 is extracted from the read record. Thereafter, in step n2, the record of the cell unique information file 2 is read. At step n3, the absolute coordinate value of the area occupied by the cell is calculated based on these two pieces of information. This absolute coordinate value can be obtained from the cell arrangement point and the cell size.

In step n4, it is determined whether or not the position occupied by the cell is included in the display area of the display device based on the absolute coordinate value. If the position of the cell is included in the display area, the mask layout data belonging to the cell is read from the mask layout data file 3 and displayed on the display device in step n5. If the cell position is not included in the display area, the process returns to step n1 and repeats the same processing.

[Problems to be solved by the invention]

In the above-mentioned conventional method, several steps must be taken to determine whether or not the cell position is included in the display area. That is, the reading of the record of the cell structure description file 1, the reading of the record of the cell specific information file 2, and the calculation of the absolute coordinate value of the occupied area of the cell based on the two pieces of information. As described above, the conventional method requires complicated processing when displaying the mask layout data.

The process most frequently performed when a part of the mask layout is enlarged and displayed is reading of a record in the cell structure description file 1. In general, input / output with respect to a disk device or the like is generally performed by treating a plurality of records as one block and improving the efficiency in units of blocks. However, the amount of data allowed in one block is defined by the disk device, which is hardware, while the records of the cell structure description file 1 contain the information (cell name N1, location points L1, L2, various pointers P1).
Etc.), the record length is long. For this reason, when a part of the mask layout is enlarged and displayed, the number of input / output circuits with the disk device is increased, and there is a problem that responsiveness is deteriorated.

An object of the present invention is to solve the above-mentioned technical problems and to provide a method of displaying mask layout data in which responsiveness is significantly improved.

[Means for solving the problem]

According to the method of displaying mask layout data of the present invention, a mask layout data file storing mask layout data and a record representing the size of a mask layout of each cell of a semiconductor integrated circuit including a large number of cells in absolute coordinate values are stored. Prepare the cell area management file and read the records of the cell area management file sequentially, based on the absolute coordinate values constituting the read record,
It is determined whether or not the area occupied by the cell corresponding to the read record is included in the display area, and when the area occupied by the cell corresponding to the read record is included in the display area, the mask It is characterized in that the mask layout data belonging to the corresponding cell is read out from the layout data file and output for display.

[Action]

According to the configuration of the present invention, since only the information on the cell size is stored in the cell area management file, the record length of each cell is shortened. Therefore, when records of a plurality of cells are input to the cell area management file and read from the cell area management file, the number of times of input / output with a disk device or the like is reduced.

The information on the cell size stored in the cell area management file is represented by the absolute coordinate value corresponding to the actual arrangement point of the cell. There is no need to do. That is, it is possible to directly determine whether the position of the cell corresponding to the read record is included in the display area of the display device by directly using the absolute coordinate values constituting the record. In this way, when displaying the mask layout data, the processing is not complicated.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a flowchart for explaining a method of displaying mask layout data according to one embodiment of the present invention.
The processing is performed by sequentially reading the contents of the cell area management file consisting only of records in which the size of each cell is represented by absolute coordinate values corresponding to the actual arrangement point of the cell. The record length of this file is 16 bytes when a numerical value is represented by 4 bytes. If the numerical value is represented by 2 bytes, the record length is only 8 bytes. Considering that the conventional cell structure description file 1 handles records as long as 72 bytes with various information, the number of input / output circuits with the disk device is reduced to 10% to 20%.

In step m1 of FIG. 1, a record of the cell area management file is read. In step m2, based on the absolute coordinate values constituting the read record,
It is determined whether or not the position of the cell corresponding to the record is included in the display area of the display device. If it is included, the mask layout data belonging to the corresponding cell is read from the mask layout data file (corresponding to the mask layout data file 3 in FIG. 3) and displayed on the display device in step m3. If the position of the cell represented by the absolute coordinate value is outside the display area of the display device, the process returns to step m1.

In this manner, according to this embodiment, a cell area management file including only records in which the size of each cell is represented by an absolute coordinate value is prepared, and when displaying mask layout data, refer to the cell area management file. Therefore, there is no need to perform complicated processing for calculating the absolute coordinate value of the area occupied by each cell as in the related art.
Further, since only the record indicating the size of each cell by the absolute coordinate value is recorded in the cell area management file, the data amount is small, and therefore, the record for many cells can be obtained by one access to the disk device. Can be read. In this way, the number of times of input / output to / from the disk device is remarkably reduced, and as a result, responsiveness when a part of the mask layout is enlarged and displayed is remarkably improved.

〔The invention's effect〕

As described above, according to the mask layout data display method of the present invention, by providing the cell area management file for managing the cell size by the absolute coordinate value, efficient display of the mask layout data can be realized. Can,
The responsiveness can be significantly improved by reducing the number of times of input / output with a disk device or the like.

[Brief description of the drawings]

FIG. 1 is a flowchart for explaining a method of displaying mask layout data according to one embodiment of the present invention, and FIG.
FIG. 3 is an explanatory diagram showing a configuration of a file in a processing device such as a CAD device. FIG. 3 is a flowchart for explaining a conventional method of displaying mask layout data. 1 ... cell structure description file, 2 ... cell specific information file, 3 ... mask layout data file

 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-172375 (JP, A) JP-A-62-57078 (JP, A) JP-A-58-221887 (JP, A)

Claims (1)

(57) [Claims] 1. A mask layout data file storing mask layout data, and a cell area management file storing a record representing the size of a mask layout of each cell of a semiconductor integrated circuit including a large number of cells in absolute coordinate values. And sequentially reads the records of the cell area management file, and, based on the absolute coordinate values constituting the read record, determines whether or not the area occupied by the cell corresponding to the read record is included in the display area. And determining, when the area occupied by the cell corresponding to the read record is included in the display area, reading and outputting the mask layout data belonging to the cell from the mask layout data file. Display method of mask layout data to be displayed.