Circuit Design and Optimization

Abstract

A method implemented on a data processing system for circuit design is described. The method comprises identifying one or more first portions of a design of a circuit, each of the one or more first portions containing a set of elements interconnected via nets, and determining whether timing of an element of a particular first portion is sensitive to degradation of a signal from a net associated with the particular first portion. In one embodiment, the method further comprises reporting the determination.

What is claimed is: 
     
         1 . A method implemented on a data processing system for circuit design, the method comprising:
 identifying one or more first portions of a design of a circuit, each of the one or more first portions containing a set of elements interconnected via nets;   determining whether timing of an element of a particular first portion is sensitive to degradation of a signal from a net associated with the particular first portion;   reporting the determination.   
     
     
         2 . The method of  claim 1 , further comprising:
 in response to a determination of sensitivity to degradation, the reporting including a recommendation to isolate the element.   
     
     
         3 . The method of  claim 1 , further comprising:
 receiving user input to select one of the first portions to assign in a block in a floor plan; and   floor planning the corresponding one of the first portions in the block according to the user input.   
     
     
         4 . The method of  claim 1 , further comprising:
 receiving input to select one of the first portions to re-assign in a block in a floor plan; and   floor planning the corresponding one of the first portions in the block according to the input.   
     
     
         5 . The method of  claim 1 , further comprising:
 identifying a plurality of functional modules of the design of the circuit; and   identifying critical paths interconnecting the plurality of functional modules,   wherein reporting the determination includes presenting the critical paths grouped according to the first portions.   
     
     
         6 . The method of  claim 5 , wherein one or more of the nets in the plurality of the first portions comprises critical paths interconnecting the functional modules. 
     
     
         7 . The method of  claim 1 , wherein the timing of the element is visualized in a cross-probe to other views of the circuit design. 
     
     
         8 . A method implemented on a data processing system for circuit design, the method comprising:
 identifying a first portion of a design of a circuit, the first portion containing a set of elements interconnected via nets; and   isolating a timing dependency of the first portion on a net connected to an element of the first portion.   
     
     
         9 . The method of  claim 8 , wherein the timing dependency is visualized in a cross-probe to other views of the circuit design. 
     
     
         10 . The method of  claim 9 , wherein the cross-probe is visualized as an RTL view of the circuit design. 
     
     
         11 . The method of  claim 9 , wherein the cross-probe is visualized as an HDL view of the circuit design. 
     
     
         12 . The method of  claim 9 , wherein the cross-probe is visualized as a three-dimensional graph of the circuit design. 
     
     
         13 . The method of  claim 8 , wherein each of the first portions is a single critical-net connected graph of elements. 
     
     
         14 . The method of  claim 9 , wherein the cross-probe visualized in a second view shows elements of critical paths in the corresponding one of the first portions. 
     
     
         15 . The method of  claim 8 , wherein each of the first portions is a single critical-net connected graph of elements. 
     
     
         16 . A method implemented on a data processing system for circuit design, the method comprising:
 identifying a first portion of a design of a circuit, the first portion containing a set of elements interconnected via nets; and   isolating a timing dependency of the first portion on a net connected to an element of the first portion.   
     
     
         17 . The method of  claim 16 , wherein the isolating comprises:
 inserting a buffer on the net as part of the first portion.   
     
     
         18 . The method of  claim 16 , wherein the isolating comprises:
 replicating a drive element of the non-critical net as part of the first portion.   
     
     
         19 . The method of  claim 16 , wherein the net is a net driving an element of the first portion and the isolating is performed automatically in response to identifying the first portion. 
     
     
         20 . The method of  claim 19 , further comprising:
 determining whether timing of the element of the first portion is sensitive to capacitive load;   wherein the isolating is performed when the element is sensitive to capacitive load.