Accurate layout modeling for centerline-based detail routing

• US 6,480,993 B1
• Filed: 12/28/1999
• Issued: 11/12/2002
• Est. Priority Date: 12/28/1999
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Todd, Eric, Suto, Gyorgy
• Primary Examiner(s): Siek, Vuthe
• Assistant Examiner(s): DO, THUAN V
• Application Number:
  US09/473,282
• Time in Patent Office: 1,050 Days
• Field of Search: 716/8, 716/14, 716/10, 716/11, 716/16
• US Class Current: 716/122
• CPC Class Codes: G06F 30/394 Routing G06F30/396 takes precedence

Abstract

Some embodiments of the invention include a computerize method of modeling a layout for a circuit design comprising receiving a plurality of circuit elements and receiving a plurality of design rules for a layout comprising the plurality of circuit elements. The computerized method further includes generating a layout model through computer automated operations wherein one or more constraints corresponding to the design rules effective at each point in a search space of the layout model are indicated by a color associated with the point.

Claims

1. A computerized method of modeling a layout for a circuit design, the method comprising:

receiving a plurality of circuit elements;

receiving a plurality of design rules for a layout comprising the plurality of circuit elements; and

generating a layout model through computer automated operations wherein one or more constraints corresponding to the plurality of design rules effective at each point in a search space of the layout model are indicated by a color associated with the point.

2. The computerized method of claim 1, further comprising searching in the layout model for a route that complies with all of the plurality of design rules.

3. The computerized method of claim 1, further comprising searching for a route in the layout model wherein the route is allowed to violate one or more of the plurality of design rules.

4. The computerized method of claim 3, further comprising modeling a gradient of the violation of the one or more design rules.

5. A computerized method of layout modeling for detail routing, the method comprising:

receiving a plurality of circuit elements and a plurality of constraints for a layout comprising the plurality of circuit elements;

associating one or more shieldings with each one of the circuit elements, wherein one or more of the plurality of constraints apply to the circuit element within the associated one or more shieldings;

assigning a first color to each one of the shieldings based on the constraints that apply within each one of shieldings;

adding each one of the shieldings to a search space for the layout; and

assigning a second color to a subarea of the search space in which two or more shieldings overlap, wherein the second color is assigned using precedence rules.

6. The computerized method of claim 5 wherein the one or more shieldings are geometric representations that cover a subarea of the search space.

7. The computerized method of claim 5 wherein the first color has two or more degrees of saturation.

8. The computerized method of claim 7 wherein a higher degree of saturation represents a higher degree of violation of the constraint represented by the color.

9. The computerized method of claim 8 wherein the higher degree of saturation takes precedence over a lower degree of saturation.

10. The computerized method of claim 5 wherein precedence rules are applied to a relationship between colors.

11. An article comprising:

a computer-readable medium including instructions that when executed cause a computer to;

apply a color to each point in a layout model for detail routing, wherein the color represents information associated with the point in a search space; and

apply color precedence rules to the color when two or more colors apply to a same point in the search space.

12. The article of claim 11 wherein the information associated with the location comprises constraints based on design rules.

13. The article of claim 11 wherein the color precedence rules are applied to relationships between different colors.

14. The article of claim 11 wherein the color precedence rules are applied to different saturations within a same color.

15. An article comprising:

a computer-readable medium including instructions that when executed cause a computer to;

receive a plurality of circuit elements;

receive a plurality of design rules for a layout comprising the plurality of circuit elements; and

generate a layout model through computer automated operations wherein one or more constraints corresponding to the design rules effective at each point in a search space of the layout model are indicated by a color associated with the point.

16. The article of claim 15, further comprising instructions that when executed cause a computer to search in the layout model for a route that complies with all of the constraints associated with the plurality of design rules.

17. The article of claim 15, further comprising instructions that when executed cause a computer to search for a route in the layout model wherein the route is allowed to violate one or more of the constraints associated with the plurality of design rules.

18. A computerized system comprising:

a computer-readable medium;

a processor; and

a computer-aided design program stored on the computer-readable medium and executable by the processor, the computer-aided design program comprising a detail router module to generate a layout model of an integrated circuit wherein the layout model generated associates one or more constraints with each point in a three-dimensional search space and wherein the one or more constraints at each point are represented by a color.

19. The computerized system of claim 18, wherein the color is combination of the colors that apply to each point.

20. The computerized system of claim 18 wherein color precedence rules are applied to relationships between different colors.