Method and Apparatus for Automatic Orientation Optimization

• US 20090199142A1
• Filed: 07/31/2008
• Published: 08/06/2009
• Est. Priority Date: 01/31/2008
• Status: Active Grant

• Current Assignee: Synopsys Incorporated
• Original Assignee: Synopsys Incorporated
• Inventors: Iyer, Mahesh Anantharaman, Arunachalam, Anand
• Granted Patent: US 7,937,682 B2
• Time in Patent Office: Days
• US Class Current: 716/132
• CPC Class Codes: G06F 30/392 Floor-planning or layout, e.g. partitioning or placement
• CPC Class Codes: G06F 30/394 Routing G06F30/396 takes precedence
• CPC Class Codes: G06F 30/398 Design verification or optimisation, e.g. using design rule check [DRC], layout versus schematics [LVS] or finite element methods [FEM] optical proximity correction [OPC] design processes G03F1/36

Abstract

Methods and apparatuses are disclosed for automatic orientation optimization in the course of generating a placed, routed, and optimized circuit design. Also disclosed are a circuit design and circuit created with the technology. Also disclosed are a circuit design and circuit created with the technology.

Claims

1. A method of circuit design, comprising:

generating a placed, routed, and optimized circuit design, including;

placing and routing a netlist of a circuit design including a first set of circuit elements; and

optimizing a set of orientations of at least part of the first set of circuit elements,

wherein the placed, routed, and optimized circuit design obeys rules specifying positioning of each circuit element of the first set of circuit elements relative to other circuit elements of the first set of circuit elements, and the rules were created specifically for the first set of circuit elements.

2. The method of claim 1, wherein said optimizing includes:

choosing the set of orientations of said at least part of the first set of circuit elements.

3. The method of claim 1, wherein each orientation of the set of orientations includes one of north, flipped north, south, flipped south, west, flipped west, east, and flipped east.

4. The method of claim 1, wherein orientation combinations of adjacent circuit elements of a same library type, of said at least part of the first set of circuit elements, exclude:

north and flipped south, south and flipped north, west and flipped east, and east and flipped west.

5. The method of claim 1, wherein said optimizing includes:

calculating a weighted cost corresponding to the set of orientations, the weighted cost including a wire length and a number of wire crossings.

6. The method of claim 1, wherein the rules were created prior to generating the placed, routed, and optimized circuit design.

7. The method of claim 1, wherein the first set of circuit elements includes at least part of one or more datapaths of the circuit design.

8. The method of claim 1, wherein the first set of circuit elements includes one or more registers of the circuit design.

9. The method of claim 1, wherein the first set of circuit elements includes one or more library elements of the circuit design.

10. The method of claim 1, wherein the optimizing maintains functionality of the circuit design and improves one or more of timing, size, congestion, and power of the circuit design.

11. The method of claim 1, wherein the optimizing includes moving one or more circuit elements of the first set of circuit elements relative to one or more other circuit elements of the first set of circuit elements.

12. The method of claim 1, wherein the optimizing includes moving the first set of circuit elements together, to a position in the circuit design.

13. The method of claim 1, wherein the rules forbid changing a position of any element of the first set of circuit elements relative to any other element of the first set of circuit elements, and said generating includes moving the first set of circuit elements all together, to a position in the circuit design.

14. The method of claim 1, wherein the rules identify particular circuit elements of the first set of circuit elements and specify, with rows and columns, positioning of the particular circuit elements relative to each other.

15. The method of claim 1, wherein the rules identify particular circuit elements of the first set of circuit elements and specify one or more gaps between the particular circuit elements.

16. The method of claim 1, wherein the rules identify particular circuit elements of the first set of circuit elements and specify one or more orientations of the particular circuit elements.

17. The method of claim 1, wherein the rules identify particular circuit elements of the first set of circuit elements and specify pin alignment of the particular circuit elements.

18. The method of claim 1, wherein the rules forbid removal of one or more of the first set of circuit elements.

19. The method of claim 1, wherein the rules specify positioning of one or more circuit elements of the first set of circuit elements relative to a design area of the circuit design.

20. The method of claim 1, wherein the rules specify removal of empty space between one or more circuit elements of the first set of circuit elements.

21. The method of claim 1, wherein the rules were created by a human involved in creating the circuit design.

22. The method of claim 1, wherein the rules were created automatically by a computer analyzing the circuit design.

23. The method of claim 1, further comprising:

creating the rules.

24. The method of claim 1, further comprising:

creating the rules prior to generating the placed, routed, and optimized circuit design.

25. The method of claim 1, further comprising:

after said generating, modifying the rules; and

repeating the generating based on the modified rules.

26. The method of claim 1, further comprising:

after said generating, modifying the netlist; and

repeating the generating based on the modified rules.

27. The method of claim 1, wherein the netlist of the circuit design further includes a second set of circuit elements of the circuit design unconstrained by the rules.

28. The method of claim 1, wherein the netlist of the circuit design further includes a second set of circuit elements of the circuit design unconstrained by the rules, and the second set of circuit elements includes one or more of a macro, a memory, and random logic of the circuit design.

29. The method of claim 1, wherein the netlist of the circuit design further includes a second set of circuit elements of the circuit design unconstrained by the rules, and said placing and routing randomly places a second set of circuit elements in the circuit design.

30. The method of claim 1, wherein the netlist of the circuit design further includes a second set of circuit elements of the circuit design unconstrained by the rules, and the generating further includes optimizing at least part of the second set of circuit elements of the circuit design.

31. The method of claim 1, wherein the netlist of the circuit design further includes a second set of circuit elements of the circuit design unconstrained by the rules, and the generating further includes optimizing at least part of the second set of circuit elements, and the optimizing of the first set of circuit elements is affected by the optimizing of the second set of circuit elements.

32. The method of claim 1, wherein the netlist of the circuit design further includes a second set of circuit elements of the circuit design unconstrained by the rules, and the generating further includes optimizing at least part of the second set of circuit elements, and the optimizing of the second set of circuit elements is affected by the optimizing of the first set of circuit elements.

33. The method of claim 1, wherein the netlist of the circuit design further includes a second set of circuit elements of the circuit design, and the placed, routed, and optimized circuit design obeys additional rules specifying positioning of each circuit element of the second set of circuit elements relative to other circuit elements of the second set of circuit elements, the additional rules being created specifically for the second set of circuit elements prior to the placing and routing of the second set of circuit elements, and the generating further includes optimizing at least part of the second set of circuit elements.

34. The method of claim 1, wherein the netlist of the circuit design further includes additional sets of circuit elements of the circuit design, and the placed, routed, and optimized circuit design obeys additional rules specifying positioning of each circuit element of each additional set of circuit elements relative to other circuit elements within a same additional set of circuit elements, the additional rules being created specifically for the additional sets of circuit elements prior to the placing and routing of the additional sets of circuit elements, and one or more additional sets of the additional sets has one or more hierarchical relationships with one or more other additional sets of the additional sets.

35. A computer readable medium with computer readable instructions for circuit design, comprising:

computer instructions generating a placed, routed, and optimized circuit design, including;

computer instructions placing and routing a netlist of a circuit design including a first set of circuit elements; and

computer instructions optimizing at least part of the first set of circuit elements, including automatic orientation optimization of at least part of the first set of circuit elements,

wherein the placed, routed, and optimized circuit design obeys rules specifying positioning of each circuit element of the first set of circuit elements relative to other circuit elements of the first set of circuit elements, and the rules were created specifically for the first set of circuit elements.

36. The medium of claim 35, wherein said computer instructions optimizing includes:

computer instructions choosing the set of orientations of said at least part of the first set of circuit elements.

37. A circuit design, comprising:

a placed, routed, and optimized circuit design, wherein the placed, routed, and optimized circuit design is created by;

placing and routing a netlist of the circuit design including a first set of circuit elements; and

optimizing at least part of the first set of circuit elements, including automatic orientation optimization of at least part of the first set of circuit elements,

wherein the placed, routed, and optimized circuit design obeys rules specifying positioning of each circuit element of the first set of circuit elements relative to other circuit elements of the first set of circuit elements, and the rules were created specifically for the first set of circuit elements.

38. The circuit design of claim 37, wherein said optimizing includes:

choosing the set of orientations of said at least part of the first set of circuit elements.

39. An electrical circuit, comprising:

circuitry including a placed, routed, and optimized circuit, wherein the placed, routed, and optimized circuit was designed by;

placing and routing a netlist of the circuit including a first set of circuit elements; and

optimizing at least part of the first set of circuit elements, including automatic orientation optimization of at least part of the first set of circuit elements,

wherein the placed, routed, and optimized circuit obeys rules specifying positioning of each circuit element of the first set of circuit elements relative to other circuit elements of the first set of circuit elements, and the rules were created specifically for the first set of circuit elements prior to the placing and routing and the optimizing, and

40. The circuit of claim 39, wherein said optimizing includes:

choosing the set of orientations of said at least part of the first set of circuit elements.