Apparatus and method for the automatic determination of a standard library height within an integrated circuit design

• US 5,737,236 A
• Filed: 02/08/1996
• Issued: 04/07/1998
• Est. Priority Date: 02/08/1996
• Status: Expired due to Fees

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Jones, Larry, Blaauw, David, Maziasz, Robert, Guruswamy, Mohankumar, Dulitz, Daniel W.
• Primary Examiner(s): Voeltz, Emanuel T.
• Assistant Examiner(s): GARBOWSKI, LEIGH M
• Application Number:
  US08/598,555
• Time in Patent Office: 789 Days
• Field of Search: 364/488, 364/487, 364/490, 364/491, 364/578
• US Class Current: 716/123
• CPC Class Codes: G06F 30/39 Circuit design at the physical level physical level design for reconfigurable circuits G06F30/347

Abstract

The present invention relates to a method (100, 150, 200) and associated data processing system (250) for determining a standard cell height within an integrated circuit design. A plurality of cell types, each cell type including a plurality of cell structures are received (102). Then, weighting values are received, one for each cell type (104). Expected intercell connection densities are preferably also received. Various target cell heights are processed with the plurality of cell types, the weighting values, and the expected intercell connection densities to generate a standard cell height (106). The standard cell height used with the integrated circuit design produces an optimized integrated circuit area, preferably a minimum area. The present invention includes a method (200) and system (250) for selecting an optimized standard cell height that, when used with a place-and-route tool to generate a physical design file (204) produces an optimized physical integrated circuit design. A method of manufacture (300) is also included.

Claims

1. A method for determining a standard cell height in an integrated circuit design, the method comprising the steps of:

(a) receiving a plurality of cell types, wherein each cell type within the plurality of cell types includes a plurality of cell structures;

(b) receiving a plurality of weighting values for the integrated circuit design, wherein each weighting value indicates a frequency of use of a respective cell type in the integrated circuit design; and

(c) iteratively processing through different cell heights while making calculations using two-dimensional areas of the plurality of cell structures and the plurality of weighting values to determine the standard cell height, wherein based on the standard cell height, an area of the integrated circuit design is optimized.

2. The method of claim 1, further comprising the step of:

(d) receiving expected intercell connection densities for the integrated circuit design, wherein the expected intercell connection densities are used in processing the plurality of structures to optimize the area of the integrated circuit design.

3. The method of claim 2, wherein the expected intercell connection densities include expected horizontal intercell connection densities and expected vertical intercell connection densities, and wherein the step of processing includes the steps of:

determining a cell height and horizontal routing area that together satisfy the expected horizontal intercell connection densities; and

determining a cell width and vertical routing area that together satisfy the expected vertical intercell connection densities, wherein the area of the integrated circuit design is minimized.

4. The method of claim 1, further comprising the step of:

stretching a height of at least one cell structure in the integrated circuit design to coincide with the standard cell height.

5. The method of claim 1, further comprising the step of:

stretching a height of at least one cell structure in the integrated circuit design to equalize heights of an adjacent cell structure transistor regipn.

6. The method of claim 1 further comprising the steps of:

(d) storing the integrated circuit design in a computer data file; and

(e) manufacturing a plurality of integrated circuits in accordance with the integrated circuit design stored in the computer data file.

7. A method for selecting an optimized standard cell height within an integrated circuit design, the method comprising the steps of:

(a) receiving a plurality of cell types, wherein each cell type within the plurality of cell types includes a plurality of cell structures;

(b) receiving a plurality of weighting values for the integrated circuit design, wherein each weighting value indicates a frequency of use of a respective cell type within the integrated circuit design;

(c) selecting a target cell height;

(d) for each cell type, selecting a cell structure having both a cell height equal to or less than the target cell height and a smallest width at the cell height;

(e) determining a respective integrated circuit design area based on selected cell structures from step (d) and the plurality of weighting values from step (b); and

repeating steps (c) through (e) for differing target cell heights to determine a cell height that produces an optimized integrated circuit design area.

8. The method of claim 7, further comprising the step of:

(g) receiving expected intercell connection densities for the integrated circuit design, wherein the expected intercell connection densities are used in determining the respective integrated circuit design area.

9. The method of claim 8, wherein the expected intercell connection densities include expected horizontal intercell connection densities and expected vertical intercell connection densities, and wherein the step of determining the respective integrated circuit design area includes the steps of:

determining a horizontal routing area that, in conjunction with the target cell height, satisfies the expected horizontal intercell connection densities; and

determining a vertical routing area that, in conjunction with selected cell structure widths, satisfies the expected vertical intercell connection densities.

10. The method of claim 7, wherein the step of selecting a cell structure having a height equal to or less than the target cell height and a minimum width further includes:

stretching the height of the cell structure to coincide with the target cell height.

11. The method of claim 7, wherein the step of selecting a cell structure having a height equal to or less than the target cell height and a minimum width further includes:

stretching the height of at least one cell structure to equalize heights of an adjacent cell structure transistor region.

12. The method of claim 7 further comprising the steps of:

(g) storing the integrated circuit design in a computer data file; and

(h) manufacturing a plurality of integrated circuits in accordance with the integrated circuit design stored in the computer data file.

13. A method for minimizing an area of an integrated circuit based on an integrated circuit design, the method comprising the steps of:

(a) selecting a standard cell library height based on the integrated circuit design and expected intercell connection densities, wherein the standard cell library height satisfies cell routing requirements;

(b) creating a physical design file using a place and route tool in accordance with the standard cell library height and the integrated circuit design, wherein the physical design file includes physical placement of circuit elements and interconnections between standard cells;

(c) determining new expected intercell connection densities based upon the physical design file to replace the expected intercell connection densities used is step (a); and

(d) repeating steps (a) through (c) until the area of the integrated circuit is minimized by optimizing the expected intercell connection densities via step (c) and optimizing the standard library height in step (a).

14. The method of claim 13, wherein the step of selecting a standard cell library height includes the steps of:

receiving a plurality of cell types, wherein each cell type within the plurality of cell types includes a plurality of cell structures;

receiving a plurality of weighting values for the integrated circuit design, wherein each weighting value indicates a frequency of use of a respective cell type; and

processing the plurality of cell structures, the plurality of weighting values, and the expected intercell connection densities to generate the standard cell library height, wherein based on the standard cell library height, an area of the integrated circuit is optimized.

15. The method of claim 13, further comprising the step of:

(e) receiving expected intercell connection densities for the integrated circuit, wherein the expected intercell connection densities are used in processing the plurality of structures to optimize the area of the integrated circuit.

16. The method of claim 13 further comprising the steps of:

(e) storing the integrated circuit design in a computer data file; and

(f) manufacturing a plurality of integrated circuits in accordance with the integrated circuit design stored in the computer data file.

17. A data processing system comprising:

a processor;

a processor bus operably coupled to the processor; and

memory operably coupled to the processor bus for storing data and instructions, wherein the memory stores instructions for;

receiving a plurality of cell types, wherein each cell type within the plurality of cell types includes a plurality of cell structures of varying heights, where .the plurality of cell types are at least partially used in an integrated circuit design;

receiving a plurality of weighting values for the integrated circuit design, wherein each weighting value indicates a frequency of use of a respective cell type within the integrated circuit design; and

processing through a plurality of different heights using the plurality of cell structures and the plurality of weighting values to determine a standard cell height for the integrated circuit design, wherein based on the standard cell height, an area of the integrated circuit design is optimized.

18. A data processing system comprising:

a processor;

a processor bus operably coupled to the processor; and

memory operably coupled to the processor bus for storing data and instructions, wherein the memory stores instructions for;

receiving a plurality of cell types, wherein each cell type within the plurality of cell types includes a plurality of cell structures at least partially used in an integrated circuit design;

receiving a plurality of weighting values for the integrated circuit design, wherein each weighting value indicates a frequency of use of a respective cell type;

selecting a target cell height;

for each cell type, selecting a cell structure having a height equal to or less than the target cell height and a minimum width; and

determining a respective integrated circuit design area based on selected cell structures and the plurality of weighting values to produce an optimized integrated circuit design area.

19. A data processing system for optimizing an integrated circuit design, the data processing system comprising:

a processor;

a processor bus operably coupled to the processor; and

memory operably coupled to the processor bus for storing data and instructions, wherein the memory stores instructions for;

selecting a standard cell library height based on the integrated circuit design and expected intercell connection densities, wherein the standard cell library height satisfies cell routing requirements;

creating a physical design file using a place and route tool in conjunction with the standard cell library height and the integrated circuit design, wherein the physical design file includes physical placement of circuit elements and interconnections between standard cells;

determining expected intercell connection densities based upon the physical design file; and

determining a standard cell library height which minimizes the area of the integrated circuit.

20. A design optimizer stored via computer readable medium, wherein the design optimizer comprises:

(a) a first plurality of computer instructions for receiving a plurality of cell types, wherein each cell type within the plurality of cell types includes a plurality of cell structures having different cell heights;

(b) a second plurality of computer instructions for receiving a plurality of weighting values for an integrated circuit design, wherein each weighting value indicates a frequency of use of a respective cell type in the integrated circuit design; and

(c) a third plurality of computer instructions for processing different cell heights using the plurality of cell structures and the plurality of weighting values to generate a standard cell height, wherein optimizes an area of the integrated circuit design.

21. A method for making an integrated circuit, the method comprising the steps of:

(a) receiving a circuit description of an integrated circuit design, wherein the circuit description includes logic functions that may be performed by a plurality of physical cell structures;

(b) receiving a plurality of cell types, wherein each cell type within the plurality of cell types includes a plurality of cell structures;

receiving a plurality of weighting values for the integrated circuit design, wherein each weighting value indicates a frequency of use of a respective cell type;

(d) processing the plurality of cell structures and the plurality of weighting values to generate a standard cell height, wherein based on the standard cell height, an area of the integrated circuit is optimized;

(e) creating a physical design file using a place and route tool in conjunction with a plurality of physical cell structures from a standard cell library conforming to the standard cell height and the integrated circuit design, the place and route tool arranging physical cell structures into a two-dimensional substrate area to form a physical design file of an integrated circuit die; and

(f) manufacturing the integrated circuit die onto one or more physical substrates.

22. A design optimizer stored via computer readable medium, wherein the computer readable medium comprises:

(a) means for receiving a plurality of cell types, wherein each cell type within the plurality of cell types includes a plurality of cell structures;

(b) means for receiving a plurality of weighting values for an integrated circuit design, wherein each weighting value indicates a frequency of use of a respective cell type;

(c) means for selecting a target cell height;

(d) means for selecting a cell structure for each cell type, the cell structure having a height equal to or less than the target cell height and a minimum width;

(e) means for determining a respective integrated circuit design area based on selected cell structures and the plurality of weighting values; and

(f) means for repeating steps (c) through (e) for differing target cell heights to determine a cell height that produces an optimized integrated circuit design area.

23. A computer readable medium, wherein the computer readable medium includes instructions for:

(a) selecting a standard cell library height based on an integrated circuit design and expected intercell connection densities of the integrated circuit design, wherein the standard cell library height satisfies cell routing requirements;

(b) creating a physical design file using a place and route tool in conjunction with the standard cell library height and the integrated circuit design, wherein the physical design file includes physical placement of circuit elements and interconnections between standard cells;

(c) determining expected intercell connection densities based upon the physical design file; and

(d) repeating steps (a) through (c) until the area of the integrated circuit is minimized.