JPH03163851A - Automatic layout system - Google Patents

Abstract

PURPOSE:To enable a layout to be corrected by a partial correction only without resorting to a notable layout alteration after completion of the layout by a method wherein redundant cells are previously arrayed in a layout while a means to make redundant wirings is provided. CONSTITUTION:Cells 12-26 corresponding to the data of a circuit connection data part 8 in an arrangement processor 1 are arranged on cell rows 9-11 quoted from a cell library 7. The kinds, quantities and positions of redundant cells to be arranged in a redundant cell arrangement part 2 are inputted from an arrangement designation part 5 so as to arrange the redundant cells 27-29 between the cells 12-26 previously arranged in the arrangement processor 1. Next, the positions and quantities of wirings in the redundant wiring formation parts are inputted from a wiring designation part 8 so as to make redundant wirings 30-33 according to said input. Finally, wirings 36-38, 42-45 to connect terminals 34, 35, 39-41 according to the data from the circuit data part 8 are made. Through these procedures, the layout can be corrected by partial correction only without resorting to a notable layout alteration after the completion of the layout.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an automatic layout system, and more particularly to an automatic layout system for standard cells that performs layout mainly for basic functional cells created at a substantially constant height. .

[Conventional technology]

Conventionally, this type of automatic layout system arranges basic functional cells (hereinafter referred to as cells) corresponding to data in the circuit connection information section 77 as shown in FIG. 9 adjacently on a cell column as shown in FIG. and a wiring processing section 75 that carefully arranges wiring between placed cells according to the connections between each element shown in the circuit connection information section 77. The cell placement and wiring generation performed here basically corresponds one-to-one with the elements and signal lines in the circuit connection information 77, and there is no extra cell or wiring that does not correspond to the circuit connection information. not exist.

[Problem to be solved by the invention]

In the layout created by this system, cells and wiring are lined up without gaps, and if a mistake is discovered in the circuit later and the circuit connection information is changed, new cells or wiring can be added or changed. It is difficult to do this, and you will essentially have to redo the layout from the beginning.

An object of the present invention is to provide an automatic layout system that can correct the layout by only making partial corrections after the layout is completed, without making major changes to the layout.

[Means to solve the problem]

An automatic layout system of the present invention includes means for arranging basic functional cells adjacent to each other in cell rows, and means for generating wiring between the cell rows to connect the basic functional cells to each other, the automatic layout system comprising: The present invention includes means for pre-arranging a desired basic functional cell that has no connection relationship with any of the basic functional cells in a cell column, and means for generating in advance a desired wiring that is not connected to any of the basic functional cells. Features.

〔Example〕

Next, the present invention will be explained in detail with reference to the drawings. FIG. 1 is a block diagram for explaining one embodiment of the present invention,
FIGS. 2 to 5 are diagrams showing the layout process using this method, and FIG. 6 is a diagram showing an example of a case where personal corrections are made to the layout prepared according to the present invention.

As shown in FIG. 1, the placement processing section 1 places cells corresponding to the data in the circuit connection information section 8 on the cell rows quoted from the cell library 7, similar to the conventional automatic layout system. FIG. 2 shows a state in which cells are arranged on cell columns, where 9 to 1] are cell columns and 12 to 26 are arranged cells.

After this normal placement is completed, preliminary cell (hereinafter referred to as redundant cell) placement 2 is performed. Here, a person inputs the type, number, and location of redundant cells to be placed from the placement specification 5, and the placement processing unit 1 places the redundant cells between the cells that have already been placed. 27-2 in Figure 3
9 indicates a redundant cell inserted between cells.

Next, preliminary wiring, that is, redundant wiring planning 3, is performed, and the designation of the position and number of wiring is entered by a human through wiring designation 6. The layout after this redundant wiring is
In the figure, 30 to 33 are generated redundant wirings.

Next, wiring processing 4 is performed. This wiring is similar to the conventional automatic layout system, and generates wiring that connects the terminals of the cells according to the data in the circuit connection information section 8. The layout created in this way is shown in FIG. 5, with normal cells 34
．． 35 etc., wiring 36 37. In addition to 38 etc., redundant cell 3
9 to 41 and redundant wiring lines 42 to 45 are present.

If it becomes necessary to make manual corrections to the layout completed in this way, for example, cell 34 in FIG.
FIG. 6 shows an example in which the wiring connected from the cell 35 to the cell 35 is changed to pass through a redundant cell 40 on the way. Here, wiring 46 is used instead of wiring 38 in FIG. 5, and wiring 47.4 is also used.
By adding 8, the desired circuit change can be easily realized.

FIG. 7 is a block diagram for explaining a second embodiment of the present invention.

In this embodiment, in addition to the second embodiment, a process 51 for estimating the number of redundant wirings is added. In the first embodiment, redundant wiring was specified by humans, but in this case, the number of redundant wiring required is calculated based on the type and number of redundant cells arranged for each wiring channel. decide. For example, in the case of the layout shown in Figure 8,
The wiring channel 57 has terminals 64, 65 of the redundant cell 59,
There are terminals 66 and 67 of the redundant cell 60, a total of four terminals.

Therefore, even if all these cells are used, the wiring will be 4
It is sufficient to prepare this book, but the cell used in this example has equivalent terminals above and below the cell (for example, cell 5
9 terminals 62 and 64, etc.), it would actually be sufficient to prepare two half the number of wires.

Therefore, for each wiring channel (sum of number of terminals of redundant cells) ÷
The redundant wiring estimation process 51 of calculation 2 is performed, and the redundant wiring generation 52 is performed based on the result. By preparing calculation formulas according to the cell library to be used and the application in this way, the number of redundant wirings can be automatically determined.

〔Effect of the invention〕

As explained above, the present invention has a means for arranging redundant cells in the layout 6 in advance and generating redundant wiring, so that when the layout is modified in response to circuit modification after the layout is completed, it is possible to significantly reduce the The result is that in many cases it is possible to respond with only partial modifications without major layout changes.

[Brief explanation of the drawing]

FIG. 1 is a block diagram for explaining one embodiment of the present invention, FIGS. 2 to 5 are diagrams showing the process of layout 1- created according to the present invention, and FIG. 6 is a diagram created according to the present invention. 7 is a block diagram for explaining the second embodiment of the present invention, and FIG. 8 is a diagram showing an example of the layout to be processed. The figure shown in FIG. 9 is a block diagram for explaining the conventional method. 1,49.74... Wiring processing unit, 2.50... Redundant cell arrangement unit, 3,52... Redundant wiring generating unit, 4.53
75... Wiring processing section, 5.54... Placement specification, 6
...Wiring specification, 7,. 55.76...Cell live, 8,56.77...Circuit connection information department, 9-11.
...Cell row, 12-26, 34.35...Cell, 27
~29 39~41.59~61...redundant cell, 30
~33 42~45...Redundant wiring, 36~38,46
~48...Wiring, 51...Redundant wiring estimate, 57,
58... Wiring channel, 62-73... Terminal.

Claims (1)

[Claims] In an automatic layout system comprising means for arranging basic functional cells adjacent to each other in a cell row, and means for generating wiring between the cell rows that connects the basic functional cells, the wiring is connected to any of the basic functional cells. An automatic layout system comprising: means for pre-arranging unrelated desired basic functional cells in a cell column; and means for pre-generating desired wiring that is not connected to any of the basic functional cells.