Method and apparatus for generating and maintaining electrical modeling data for a deep sub-micron integrated circuit design

• US 6,249,903 B1
• Filed: 03/31/1998
• Issued: 06/19/2001
• Est. Priority Date: 03/31/1998
• Status: Expired due to Term

• Current Assignee: Mentor Graphics Corporation (Siemens AG)
• Original Assignee: Mentor Graphics Corporation (Siemens AG)
• Inventors: McSherry, Michael C., Todd, Robert A., Nugyen, Paul M., Strobel, Richard E.
• Primary Examiner(s): Smith, Matthew
• Assistant Examiner(s): DO, THUAN V
• Application Number:
  US09/052,915
• Time in Patent Office: 1,176 Days
• Field of Search: 395/500.02, 395/500.06, 395/500.13, 716/12, 716/11
• US Class Current: 716/115
• 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

A parasitic extraction tool (PEX) is provided to generate electrical modeling data for an integrated circuit (IC) design, e.g. a deep sub-micron IC design. The PEX includes a read function for reading extracted connectivity and geometrical data of various layout cell hierarchies of the IC design, that are organized and indexed by layout nets. The PEX also includes a write function for writing generated electrical modeling data into a parasitic database (PDB), which is physically organized to accommodate physical storage of the electrical modeling data in multiple physical media, and concurrent usage of the electrical data by multiple client applications, e.g. post layout analysis tool. In one embodiment, the PDB further includes an application interface that shields the physical organization of the PDB, and a logical abstraction of the physical organization to facilitate implementation of the application interface.

Claims

1. A machine readable storage medium having stored therein a plurality of machine executable instructions that implement a parasitic extraction tool to generate electrical modeling data for an integrated circuit (IC) design, wherein the parasitic extraction tool includes a read function to input extracted connectivity and geometrical data of various layout nets of the IC design from at least one filtered database, said connectivity and geometric data having been filtered based at least in part on parasitic effect windows of respective layout layers, wherein a particular parasitic effect window defines a distance from geometric shapes on a given layout layer beyond which parasitic effects are ignored.

2. The machine readable storage medium of claim 1, wherein the at least one filtered database is organized by layout cell hierarchies.

3. The machine readable storage medium of claim 1, wherein the read function is to access the at least one filtered database using layout net indices.

4. A machine readable storage medium having stored therein a plurality of machine executable instructions that implement a parasitic extraction tool to generate electrical modeling data for an integrated circuit (IC) design, said electrical modeling data having been extracted from at least one filtered database, said filtered database having been filtered based at least in part on parasitic effect windows of respective layout layers of the IC design, wherein a particular parasitic effect window defines a distance from geometric shapes on a given layout layer beyond which parasitic effects are ignored, said parasitic extraction tool including a write function to store the generated electrical modeling data into a parasitic database (PDB), said PDB comprising multiple physical storage media, and wherein said write function is to write the generated electrical modeling data to the PDB in a logical organization of interrelated records to accommodate concurrent access by multiple client applications.

5. The machine readable storage medium of claim 4, wherein the interrelated records comprise one or more associated blocks of contiguous storage location chunks.

6. The machine readable storage medium of claim 4, wherein the write function locates each interrelated record by locating a first storage location chunk of a respective record.

7. The machine readable storage medium of claim 4, wherein the write function stores the generated electrical model data into the interrelated records, employing records of different record types.

8. The machine readable storage medium of claim 7, wherein the different record types include a raw record type and a counted record type, wherein a last read/write position of a record of the raw record type is not tracked, and the last read/write position of a record of the counted record type is tracked.

9. The machine readable storage medium of claim 4, wherein the PDB further comprises a physical manager having a create function to create instances of input/output streams, and wherein the write function is further to employ the create function to create the interrelated records through corresponding created input/output stream instances.

10. The machine readable storage medium of claim 4, wherein the PDB further comprises a physical manager having a locate function to locate created instances of input/output streams, and wherein the write function is further to employ the locate function to locate particular interrelated records through corresponding created input/output stream instances.

11. The machine readable storage medium of claim 4, wherein the logical organization of interrelated records comprises a logical abstraction of the interrelated records, including one or more of a logical PDB file entity, a logical layer name table entity, a logical pin signature table entity, a logical device signature table entity and a logical net name table entity, and wherein the write function accesses the logical organization through the logical abstraction of the interrelated records.

12. The machine readable storage medium of claim 4, wherein the logical organization of interrelated records comprises a logical abstraction of the interrelated records including one or more of a logical parasitic model entity, a logical local parasitic device entity and a global parasitic device entity, and wherein the write function accesses the logical organization through the logical abstraction of the interrelated records.

13. The machine readable storage medium of claim 4, wherein the interrelated records include records of different record types, the logical organization of interrelated records comprises a logical abstraction of the interrelated records including different logical abstraction entities, employing records of different record types, and wherein the write function accesses the logical organization through the logical abstraction of the interrelated records.

14. The machine readable storage medium of claim 4, wherein the logical organization of interrelated records includes an application interface to facilitate access to the logical organization and to shield the multiple physical storage media of the PDB from an accessing client application, and wherein the write function accesses the logical organization through the application interface.

15. The machine readable storage medium of claim 14, wherein the application interface is class based, including one or more of a read-write class, a pin signature class, a parasitic device signature class, and a parasitic model class, and wherein the write function accesses the logical organization through the class based application interface.

16. The machine readable storage medium of claim 14, wherein the application interface is class based, including one or more of a parasitic model class, a device pin class, a port pin class and a delay information class, and wherein the write function accesses the logical organization through the class based application interface.

17. The machine readable storage medium of claim 14, wherein the application interface is class based, including one or more of a parasitic model class, a parasitic device list class, a local parasitic device class and a global parasitic device class, and wherein the write function accesses the logical organization through the class based application interface.

18. A plurality of machine readable storage media having stored therein a parasitic database (PDB) of generated electrical modeling data of an integrated circuit (IC) design, said electrical modeling data having been extracted from at least one filtered database, said filtered database having been filtered based at least in part on parasitic effect windows of respective layout layers of the IC design, wherein a particular parasitic effect window defines a distance from geometric shapes on a given layout layer beyond which parasitic effects are ignored, the PDB being constituted with segments of storage location chunks, the generated electrical modeling data of the IC design being stored in a logical organization of interrelated records constituted with one or more associated blocks of contiguous storage location chunks.

19. The machine readable storage media of claim 18, wherein each interrelated record is located by locating a first storage location chunk of a respective record.

20. The machine readable storage media of claim 18, wherein the interrelated records are typed including a raw record type and a counted record type, wherein a last read/write position of a record of the raw record type is not tracked, and the last read/write position of a record of the counted record type is tracked.

21. The machine readable storage media of claim 18, wherein the PDB further comprises a physical manager having a locate function to locate created instances of input/output streams to facilitate accessing the interrelated records of the generated electrical modeling data through corresponding created input/output stream instances.

22. The machine readable storage media of claim 21, wherein the physical manager further comprises a create function to create the instances of input/output streams.

23. The machine readable storage media of claim 18, wherein the PDB further comprises a logical abstraction of the interrelated records, including one or more of a logical PDB file entity, a logical layer name table entity, a logical pin signature table entity, a logical device signature table entity and a logical net name table entity.

24. The machine readable storage media of claim 18, wherein the PDB further comprises a logical abstraction of the interrelated records including one or more of a logical parasitic model entity, a logical local parasitic device entity and a global parasitic device entity.

25. The machine readable storage media of claim 18, wherein the interrelated records include records of different record types, the PDB further comprises a logical abstraction of the interrelated records including different logical abstraction entities, employing the records of different record types.

26. The machine readable storage media of claim 18, wherein the PDB includes an application interface to facilitate access to the PDB and shield the physical organization of the PDB from an accessing client application.

27. The machine readable storage media of claim 26, wherein the application interface is class based, including one or more of a read-write class, a pin signature class, a parasitic device signature class, and a parasitic model class.

28. The machine readable storage media of claim 26, wherein the application interface is class based, including one or more of a parasitic model class, a device pin class, a port pin class and a delay information class.

29. The machine readable storage media of claim 26, wherein the application interface is class based, including one or more of a parasitic model class, a parasitic device list class, a local parasitic device class and a global parasitic device class.

30. A computer system comprising:

a storage medium having stored therein a plurality of machine executable instructions that implement a parasitic extraction tool to generate electrical modeling data for an integrated circuit (IC) design, wherein the parasitic extraction tool includes a read function to input extracted connectivity and geometrical data of various layout nets of the IC design from at least one filtered database, said connectivity and geometrical data having been filtered based at least in part on parasitic effect windows of respective layout layers, wherein a particular parasitic effect window defines a distance from geometric shapes on a given layout layer beyond which parasitic effects are ignored; and

an execution unit coupled to the storage medium to execute the machine executable instructions.

31. The computer system of claim 30, wherein the at least one filtered database is organized by layout cell hierarchies.

32. The computer system of claim 30, wherein the read function is to access the at least one filtered database using layout net indices.

33. A computer system comprising:

a storage medium having stored therein a plurality of machine executable instructions that implement a parasitic extraction tool to generate electrical modeling data for an integrated circuit (IC) design, said electrical modeling data having been extracted from at least one filtered database, said filtered database having been filtered based at least in part on parasitic effect windows of respective layout layers of the IC design, wherein a particular parasitic effect window defines a distance from geometric shapes on a given layout layer beyond which parasitic effects are ignored, said parasitic extraction tool including a write function to store the generated electrical modeling data into a parasitic database (PDB), said PDB comprising multiple physical storage media, and wherein said write function is to write the generated electrical modeling dada to the PDB in a logical organization of interrelated records to accommodate concurrent access by multiple client applications; and

an execution unit coupled to the storage medium to execute the machine executable instructions.

34. The computer system of claim 33, wherein the interrelated records comprise one or more associated blocks of contiguous storage location chunks.

35. The computer system of claim 33, wherein the write function locates each record by locating a first storage location chunk of a respective record.

36. The computer system of claim 33, wherein the write function stores the generated electrical model data into the interrelated records, employing records of different record types.

37. The computer system of claim 36, wherein the different record types include a raw record type and a counted record type, wherein a last read/write position of a record of the raw record type is not tracked, and the last read/write position of a record of the counted record type is tracked.

38. The computer system of claim 33, wherein the PDB further comprises a physical manager having a create function to create instances of input/output streams, and wherein the write is function further to employ the create function to create the interrelated records through corresponding created input/output stream instances.

39. The computer system of claim 33, wherein the PDB further comprises a physical manager having a locate function to locate created instances of input/output streams, and wherein the write function is further to employ the locate function to locate particular interrelated records through corresponding created input/output stream instances.

40. The computer system of claim 33, wherein the logical organization of interrelated records comprises a logical abstraction of the interrelated records, including one or more of a logical PDB file entity, a logical layer name table entity, a logical pin signature table entity, a logical device signature table entity and a logical net name table entity, and wherein the write function accesses the logical organization through the logical abstraction of the interrelated records.

41. The computer system of claim 33, wherein the logical organization of interrelated records comprises a logical abstraction of the interrelated records including one or more of a logical parasitic model entity, a logical local parasitic device entity and a global parasitic device entity, and wherein the write function accesses the logical organization through the logical abstraction of the interrelated records.

42. The computer system of claim 33, wherein the interrelated records include records of different record types, the logical organization of interrelated records comprises a logical abstraction of the interrelated records including different logical abstraction entities, employing records of different record types, and wherein the write function accesses the logical organization through the logical abstraction of the interrelated records.

43. The computer system of claim 33, wherein the logical organization of interrelated records includes an application interface to facilitate access to the logical organization and to shield the multiple physical storage media of the PDB from an accessing client application, and wherein the write function accesses the logical organization through the application interface.

44. The computer system of claim 43, wherein the application interface is class based, including one or more of a read-write class, a pin signature class, a parasitic device signature class, and a parasitic model class, and the write function accesses the logical organization through the class based application interface.

45. The computer system of claim 43, wherein the application interface is class based, including one or more of a parasitic model class, a device pin class, a port pin class and a delay information class, and wherein the write function accesses the logical organization through the class based application interface.

46. The computer system of claim 43, wherein the application interface is class based, including one or more of a parasitic model class, a parasitic device list class, a local parasitic device class and a global parasitic device class, and wherein the write function accesses the logical organization through the class based application interface.

47. A computer system comprising:

a plurality of storage media having stored therein a parasitic database (PDB) of generated electrical modeling data of an integrated circuit (IC) design, said electrical modeling data having been extracted from at least one filtered database, said filtered database having been filtered based at least in part on parasitic effect windows of respective layout layers of the IC design, wherein a particular parasitic effect window defines a distance from geometric shapes on a given layout layer beyond which parasitic effects are ignored, the PDB being constituted with segments of storage location chunks, the generated electrical modeling data of the IC design being stored in a logical organization of interrelated records constituted with one or more associated blocks of contiguous storage location chunks; and

an execution unit coupled to the storage medium to execute the machine executable instructions.

48. The computer system of claim 47, wherein each interrelated record is located by locating a first storage location chunk of a respective record.

49. The computer system of claim 47, wherein the interrelated records are typed including a raw record type and a counted record type, wherein a last read/write position of a record of the raw record type is not tracked, and the last read/write position of a record of the counted record type is tracked.

50. The computer system of claim 47, wherein the PDB further comprises a physical manager having a locate function to locate created instances of input/output streams to facilitate accessing the interrelated records of the generated electrical modeling data through corresponding created input/output stream instances.

51. The computer system of claim 50, wherein the physical manager further comprises a create function to create the instances of input/output streams.

52. The computer system of claim 47, wherein the PDB further comprises a logical abstraction of the interrelated records, including one or more of a logical PDB file entity, a logical layer name table entity, a logical pin signature table entity, a logical device signature table entity and a logical net name table entity.

53. The computer system of claim 47, wherein the PDB further comprises a logical abstraction of the interrelated records including one or more of a logical parasitic model entity, a logical local parasitic device entity and a global parasitic device entity.

54. The computer system of claim 47, wherein the interrelated records include records of different record types, the PDB further comprises a logical abstraction of the interrelated records including different logical abstraction entities, employing the records of different record types.

55. The computer system of claim 47, wherein the PDB includes an application interface to facilitate access to the PDB and to shield the physical organization of the PDB from an accessing client application.

56. The computer system of claim 55, wherein the application interface is class based, including one or more of a read-write class, a pin signature class, a parasitic device signature class, and a parasitic model class.

57. The computer system of claim 55, wherein the application interface is class based, including one or more of a parasitic model class, a device pin class, a port pin class and a delay information class.

58. The computer system of claim 55, wherein the application interface is class based, including one or more of a parasitic model class, a parasitic device list class, a local parasitic device class and a global parasitic device class.

59. A machine implemented method comprising:

reading extracted connectivity and geometrical data of various layout nets of an integrated circuit (IC) design from a filtered database, said connectivity and geometrical data having been filtered based at least in part on parasitic effect windows of respective layout layers, wherein a particular parasitic effect window defines a distance from geometric shapes on a given layout layer beyond which parasitic effects are ignored;

generating electrical modeling data using the extracted connectivity and geometrical data of the various layout nets read; and

writing the generated electrical modeling data into a parasitic database (PDB) physically organized to accommodate physical storing of the generated electrical modeling data in multiple physical media, and concurrent access by multiple client applications.

60. The method of claim 59, wherein reading extracted connectivity and geometrical data comprises accessing one or more databases of extracted connectivity and geometrical data organized by layout cell hierarchies.

61. The computer system of claim 59, wherein writing the generated electrical modeling data comprises locating a record by locating a first storage location chunk of the record.