Non-orthogonal structures and space tiles for layout, placement, and routing of an integrated circuit

• US 7,096,445 B1
• Filed: 01/14/2003
• Issued: 08/22/2006
• Est. Priority Date: 01/14/2003
• Status: Expired due to Fees

• Current Assignee: Cadence Design Systems Incorporated (Cadence Group)
• Original Assignee: Cadence Design Systems Incorporated (Cadence Group)
• Inventors: Pucci, Steven Lee, Nequist, Eric Martin
• Primary Examiner(s): Kik, Phallaka
• Application Number:
  US10/342,863
• Time in Patent Office: 1,316 Days
• Field of Search: 716/8, 716/7, 716/12, 716/9, 716/10, 716/13, 716/14
• US Class Current: 716/119
• CPC Class Codes: G06F 30/39 Circuit design at the physical level physical level design for reconfigurable circuits G06F30/347

Abstract

Disclosed is an improved approach for maintaining the structures for objects in a layout. A single type of structure is maintained that can be used to store or track a polygon of any shape, as long as the shape possesses a supported number of sides. The structure is capable of supporting irregular polygons or objects having angled edges. In one approach, the structure maintains information about each polygon as if that polygon is an octagon. Therefore, any polygon having eight or less orthogonal or diagonal sides can be supported using this structure.

Claims

1. A method for implementing a layout of an integrated circuit, comprising:

identifying one or more objects to be placed on an integrated circuit layout;

tracking each of the one or more objects using an octagon-based structure, the octagon-based structure maintains at least eight data values, with the at least eight data values corresponding to sides of an octagon shape, the at least eight data values identify locations of corresponding sides along a perpendicular axis to the sides, and

in which at least one of the at least eight data values corresponds to a zero length side, in which the octagon shape is a degenerate octagon having less than eight sides.

10. The method of claims 1, 2 or 8 in which the one or more objects comprise a space tile that is based upon a contour of an existing shape in the layout.

11. The method of claims 1, 2 or 8 in which at least one of the one or more objects has less than eight sides.

14. The method of claim 1, 12 or 13 in which the at least eight data values identify angle information for at least one of the sides of the octagon shape.

15. The method of claim 14 in which the angle information is implicit based upon a default angle value.

2. A method for implementing a layout of an integrated circuit, comprising:

identifying one or more objects to be placed on an integrated circuit layout;

tracking each of the one or more objects using an octagon-based structure in which the octagon-based structure comprises one or more data elements to identify neighboring objects with respect to the one or more objects.

3. The method of claim 2 in which neighboring objects are tracked along each edge of the octagon-based structure.

4. The method of claim 3 in which relational information is maintained for a non-orthogonal edge between one of the one or more objects and its neighboring object.

5. The method of claim 3 further comprising:

identifying a routing path based upon tracking neighboring objects.

6. The method of claim 5 in which the neighboring objects are free space tiles.

7. The method of claim 5 in which the routing path is a non-orthogonal routing path.

12. The method of claim 2 in which the octagon-based structure maintains at least eight data values, with the at least eight data values corresponding to sides of an octagon shape.

8. A method for implementing a layout of an integrated circuit, comprising:

identifying one or more objects to be placed on an integrated circuit layout;

tracking each of the one or more objects using an octagon-based structure in which at least two objects are merged together into a single shape, wherein a single octagon-based structure is used to track the single shape.

9. The method of claim 8 further comprising:

identifying the at least two objects to merge;

confirming that the at least two objects share a common edge;

verifying that edges to sum together in the single shape are properly aligned;

verifying that the single shape has a supported number of sides; and

confirming that the single shape is convex.

13. The method of claim 8 in which the octagon-based structure maintains at least eight data values, with the at least eight data values corresponding to sides of an octagon shape.

16. A computer program product comprising a computer usable medium having executable code to execute a process for implementing a layout of an integrated circuit, the process comprising:

identifying one or more objects to be placed on an integrated circuit layout;

tracking each of the one or more objects using an octagon-based structure, the octagon-based structure maintains at least eight data values, with the at least eight data values corresponding to sides of an octagon shape, the at least eight data values identify locations of corresponding sides along a perpendicular axis to the sides, and in which at least one of the at least eight data values corresponds to a zero length side, in which the octagon shape is a degenerate octagon having less than eight sides.

17. The computer program product of claim 16 in which the at least eight data values identify angle information for at least one of the sides of the octagon shape.

25. The computer program product of claims 16, 20 or 24 in which the one or more objects comprise a space tile that is based upon a contour of an existing shape in the layout.

26. The computer program product of claims 16, 20 or 24 in which at least one of the one or more objects has less than eight sides.

18. A system for implementing a layout of an integrated circuit, comprising:

means for identifying one or more objects to be placed on an integrated circuit layout;

means for tracking each of the one or more objects using an octagon-based structure, the octagon-based structure maintains at least eight data values, with the at least eight data values corresponding to sides of an octagon shape, the at least eight data values identify locations of corresponding sides along a perpendicular axis to the sides, and in which at least one of the at least eight data values corresponds to a zero length side, in which the octagon shape is a degenerate octagon having less than eight sides.

19. The system of claim 18 in which the at least eight data values identify angle information for at least one of the sides of the octagon shape.

29. The system of claims 18, 22 or 28 in which the one or more objects comprise a space tile that is based upon a contour of an existing shape in the layout.

30. The system of claims 18, 22 or 28 in which at least one of the one or more objects has less than eight sides.

20. A computer program product comprising a computer usable medium having executable code to execute a process for implementing a layout of an integrated circuit, the process comprising:

identifying one or more objects to be placed on an integrated circuit layout;

tracking each of the one or more objects using an octagon-based structure, in which the octagon-based structure comprises one or more data elements to identify neighboring objects with respect to the one or more objects.

21. The computer program product of claim 20 in which neighboring objects are tracked along each edge of the octagon-based structure.

22. A system for implementing a layout of an integrated circuit, comprising:

means for identifying one or more objects to be placed on an integrated circuit layout;

means for tracking each of the one or more objects using an octagon-based structure, in which the octagon-based structure comprises one or more data elements to identify neighboring objects with respect to the one or more objects.

23. The system of claim 22 in which neighboring objects are tracked along each edge of the octagon-based structure.

24. A computer program product comprising a computer usable medium having executable code to execute a process for implementing a layout of an integrated circuit, the process comprising:

identifying one or more objects to be placed on an integrated circuit layout;

tracking each of the one or more objects using an octagon-based structure, in which at least two objects are merged together into a single shape, wherein a single octagon-based structure is used to track the single shape.

27. The computer program product of claim 24, wherein the process further comprising:

identifying the at least two objects to merge;

confirming that the at least two objects share a common edge;

verifying that edges to sum together in the single shape are properly aligned;

verifying that the single shape has a supported number of sides; and

confirming that the single shape is convex.

28. A system for implementing a layout of an integrated circuit, comprising:

means for identifying one or more objects to be placed on an integrated circuit layout;

means for tracking each of the one or more objects using an octagon-based structure, in which at least two objects are merged together into a single shape, wherein a single octagon-based structure is used to track the single shape.

31. The system of claim 28 further comprising:

means for identifying the at least two objects to merge;

means for confirming that the at least two objects share a common edge;

means for verifying that edges to sum together in the single shape are properly aligned;

means for verifying that the single shape has a supported number of sides; and

means for confirming that the single shape is convex.