Design analysis workstation for analyzing integrated circuits

1. A method of analyzing a design of an integrated circuit, the method comprising:

defining a logical representation of at least a portion of the integrated circuit, the logical representation comprising a plurality of annotation objects drawn on an annotation layer and associated with respective physical features of the integrated circuit, the plurality of annotation objects being selected from a set of predetermined annotation object types including at least:

a wire annotation object defining a logical representation of a wire of the integrated circuit; and

a contact annotation object defining a logical representation of a connection between two or more physical features of the integrated circuit;

selecting from among the plurality of annotation objects drawn on the annotation layer, a set of annotation objects interconnected by at least contact annotation objects;

identifying, from among the selected set of annotation objects, each annotation object which has a respective unambiguous signal value; and

propagating the respective unambiguous signal value from each identified annotation object to all other annotation objects in the selected set.

2. The method as claimed in claim 1 wherein propagating the respective signal value comprises propagating the respective signal value of a cell annotation object to a wire annotation object connected to the cell annotation object.

3. The method as claimed in claim 2 , further comprising propagating the signal value from the wire annotation object to all annotation objects connected to contact annotation objects in the selected set.

4. The method as claimed in claim 1 further comprising detecting a signal value conflict if two different signal values are propagated to a given annotation object.

5. The method as claimed in claim 4 , further comprising, when a signal value conflict is detected, displaying information about the detected signal value conflict on a design analysis workstation.

6. The method as claimed in claim 5 wherein displaying the information comprises displaying a pop-up view with at least one signal value conflict location displayed therein.

7. The method as claimed in claim 6 further comprising providing navigation buttons for browsing and inspecting the at least one signal value conflict.

8. The method as claimed in claim 1 wherein if the connected set of annotations objects has two or more different signal values, each of the different signal values is propagated until a signal value conflict is detected.

9. The method as claimed in claim 1 further comprising preventing the propagation of signal values by a first engineer analyst to annotation objects created by another engineer analyst if the annotation objects are locked by the other engineer analyst.

10. The method as claimed in claim 9 further comprising flagging the annotation objects to which a signal value is not propagated.

11. A design analysis workstation for facilitating analysis of an integrated circuit, comprising:

a facility for defining a logical representation of at least a portion of the integrated circuit, the logical representation comprising a plurality of annotation objects drawn on an annotation layer and associated with respective physical features of the integrated circuit, the plurality of annotation objects being selected from a set of predetermined annotation object types including at least:

a wire annotation object defining a logical representation of a wire of the integrated circuit; and

a contact annotation object defining a logical representation of a connection between two or more physical features of the integrated circuit;

a facility for selecting from among the plurality of annotation objects drawn on the annotation layer, a set of annotation objects interconnected by at least contact annotation objects;

a facility for identifying, from among the selected set of annotation objects, each annotation object which has a respective unambiguous signal value; and

a facility for propagating the respective unambiguous signal value from each identified annotation object to all other annotation objects in the selected set.

12. The design analysis workstation as claimed in claim 11 wherein the facility for propagating the respective signal value propagates the respective signal value of a cell annotation object to a wire annotation object connected to the cell annotation object.

13. The design analysis workstation as claimed in claim 12 , wherein the facility for propagating the respective signal value propagates the respective signal value from the wire annotation object to all annotation objects connected to contact annotation objects in the selected set.

14. The design analysis workstation as claimed in claim 11 wherein the facility for propagating detects a signal value conflict if two different signal values are propagated to a given annotation object.

15. The design analysis workstation as claimed in claim 14 further comprising a visual display of information about the detected signal value conflict.

16. The design analysis workstation as claimed in claim 5 further comprising a pop-up view with at least one signal value conflict location displayed therein.

17. The design analysis workstation as claimed in claim 16 further comprising navigation buttons for browsing and inspecting the at least one displayed signal value conflict.

18. The design analysis workstation as claimed in claim 11 wherein the facility for propagating signal values propagates the signals signal values until a signal value conflict is detected.

19. The design analysis workstation as claimed in claim 11 wherein the facility for propagating signal values propagates signal values only to annotation objects that are not locked, unless the locked annotation objects were created by an engineer analyst operating the design analysis workstation to propagate the signal values.

20. The design analysis workstation as claimed in claim 19 wherein the facility of propagating signal values flags annotation objects to which a signal value was not propagated.