Method and system for creating electronic circuitry

Abstract

According to a first model of an operation of circuitry, a first set of estimates of the operation is generated in response to a set of conditions, including a first estimate of the operation in response to a first condition. According to a second model of the operation, a second set of estimates of the operation is generated in response to the first condition and the first set. In response to a comparison between the first estimate and the second set, a subset of the first set is selected. According to the second model, an estimate of the operation is generated in response to a second condition and the selected subset.

What is claimed is:  
     
         1 . A system, comprising: 
 a computer for: 
 according to a first model of an operation of circuitry, generating a first set of estimates of the operation in response to a set of conditions, including a first estimate of the operation in response to a first condition;  
 according to a second model of the operation, generating a second set of estimates of the operation in response to the first condition and the first set;  
 in response to a comparison between the first estimate and the second set, selecting a subset of the first set; and  
 according to the second model, generating an estimate of the operation in response to a second condition and the selected subset.  
   
     
     
         2 . The system of  claim 1  wherein the first model includes a circuit simulator.  
     
     
         3 . The system of  claim 1  wherein the second model includes a characteristic equation.  
     
     
         4 . The system of  claim 3  wherein the second model includes a characterization table that includes the characteristic equation.  
     
     
         5 . The system of  claim 3  wherein the second model is a static timing analysis model including the characteristic equation.  
     
     
         6 . The system of  claim 3  wherein the computer is for generating the second set by: 
 determining respective sets of constant elements of the characteristic equation in response to subsets of the first set; and  
 according to the characteristic equation, in response to the first condition, generating the second set including respective estimates of the operation in response to the sets of constant elements.  
 
     
     
         7 . The system of  claim 6  wherein the computer is for selecting the selected subset from among the subsets of the first set in response to the comparison, the comparison being a comparison between the first estimate and the estimates of the second set.  
     
     
         8 . The system of  claim 7  wherein: 
 the subsets of the first set are respectively associated with the sets of constant elements, so the selected subset of the first set is associated with a particular set of constant elements;  
 the estimates of the second set are respectively associated with the sets of constant elements, so a particular estimate of the second set is associated with the particular set of constant elements; and  
 among the estimates of the second set, the particular estimate is closest to the first estimate.  
 
     
     
         9 . The system of  claim 1  wherein the operation is a response time of the circuitry.  
     
     
         10 . The system of  claim 1  wherein the operation is a propagation delay of the circuitry.  
     
     
         11 . The system of  claim 1  wherein the conditions include at least two types of conditions.  
     
     
         12 . The system of  claim 1  wherein the conditions include at least three types of conditions.  
     
     
         13 . The system of  claim 1  wherein the conditions include capacitive loadings of the circuitry.  
     
     
         14 . The system of  claim 1  wherein the conditions include input transition times of the circuitry.  
     
     
         15 . The system of  claim 14  wherein the conditions include at least two types of input transition times of the circuitry.  
     
     
         16 . The system of  claim 1  wherein the circuitry is integrated circuitry.  
     
     
         17 . A method, comprising: 
 with a first computer-implemented model of an operation of circuitry, generating a first set of estimates of the operation in response to a set of conditions, including a first estimate of the operation in response to a first condition;    with a second computer-implemented model of the operation, generating a second set of estimates of the operation in response to the first condition and the first set;    in response to a comparison between the first estimate and the second set, selecting a subset of the first set; and    with the second computer-implemented model, generating an estimate of the operation in response to a second condition and the selected subset.    
     
     
         18 . The method of  claim 17  wherein the generating of the first set of estimates comprises: 
 with the first computer-implemented model of the operation, generating the first set of estimates of the operation in response to the set of conditions, the first computer-implemented model including a circuit simulator.  
 
     
     
         19 . The method of  claim 17  wherein the generating of the second set of estimates comprises: 
 with the second computer-implemented model of the operation, generating the second set of estimates, the second computer-implemented model including a characteristic equation.  
 
     
     
         20 . The method of  claim 20  wherein the generating of the second set of estimates comprises: 
 with the second computer-implemented model of the operation, generating the second set of estimates, the second computer-implemented model including a characterization table that includes the characteristic equation.  
 
     
     
         21 . The method of  claim 20  wherein the generating of the second set of estimates comprises: 
 with the second computer-implemented model of the operation, generating the second set of estimates, the second computer-implemented model being a static timing analysis model including the characteristic equation.  
 
     
     
         22 . The method of  claim 20  wherein the generating of the second set of estimates comprises: 
 determining respective sets of constant elements of the characteristic equation in response to subsets of the first set; and  
 according to the characteristic equation, in response to the first condition, generating the second set including respective estimates of the operation in response to the sets of constant elements.  
 
     
     
         23 . The method of  claim 22  wherein the selecting of the subset comprises: 
 selecting the selected subset from among the subsets of the first set in response to the comparison, the comparison being a comparison between the first estimate and the estimates of the second set.  
 
     
     
         24 . The method of  claim 23  wherein the selecting of the subset comprises: 
 selecting the selected subset from among the subsets of the first set in response to the comparison, 
 the subsets of the first set being respectively associated with the sets of constant elements, so the selected subset of the first set is associated with a particular set of constant elements;  
 the estimates of the second set being respectively associated with the sets of constant elements, so a particular estimate of the second set is associated with the particular set of constant elements; and  
 among the estimates of the second set, the particular estimate being closest to the first estimate.  
 
 
     
     
         25 . The method of  claim 17  wherein the generating of the first set of estimates comprises: 
 with the first computer-implemented model of the operation, generating the first set of estimates of the operation in response to the set of conditions, the operation being a response time of the circuitry.  
 
     
     
         26 . The method of  claim 17  wherein the generating of the first set of estimates comprises: 
 with the first computer-implemented model of the operation, generating the first set of estimates of the operation in response to the set of conditions, the operation being a propagation delay of the circuitry.  
 
     
     
         27 . The method of  claim 17  wherein the generating of the first set of estimates comprises: 
 with the first computer-implemented model of the operation, generating the first set of estimates of the operation in response to the set of conditions, the conditions including at least two types of conditions.  
 
     
     
         28 . The method of  claim 17  wherein the generating of the first set of estimates comprises: 
 with the first computer-implemented model of the operation, generating the first set of estimates of the operation in response to the set of conditions, the conditions including at least three types of conditions.  
 
     
     
         29 . The method of  claim 17  wherein the generating of the first set of estimates comprises: 
 with the first computer-implemented model of the operation, generating the first set of estimates of the operation in response to the set of conditions, the conditions including capacitive loadings of the circuitry.  
 
     
     
         30 . The method of  claim 17  wherein the generating of the first set of estimates comprises: 
 with the first computer-implemented model of the operation, generating the first set of estimates of the operation in response to the set of conditions, the conditions including input transition times of the circuitry.  
 
     
     
         31 . The method of  claim 30  wherein the generating of the first set of estimates comprises: 
 with the first computer-implemented model of the operation, generating the first set of estimates of the operation in response to the set of conditions, the conditions including at least two types of input transition times of the circuitry.  
 
     
     
         32 . The method of  claim 17  wherein the generating of the first set of estimates comprises: 
 with the first computer-implemented model of the operation, generating the first set of estimates of the operation in response to the set of conditions, the circuitry being integrated circuitry.  
 
     
     
         33 . A computer program product, comprising: 
 a computer application processable by a computer for causing the computer to: 
 according to a first model of an operation of circuitry, generate a first set of estimates of the operation in response to a set of conditions, including a first estimate of the operation in response to a first condition;  
 according to a second model of the operation, generate a second set of estimates of the operation in response to the first condition and the first set;  
 in response to a comparison between the first estimate and the second set, select a subset of the first set; and  
 according to the second model, generate an estimate of the operation in response to a second condition and the selected subset; and  
   apparatus from which the computer application is accessible by the computer.    
     
     
         34 . The computer program product of  claim 33  wherein the first model includes a circuit simulator.  
     
     
         35 . The computer program product of  claim 33  wherein the second model includes a characteristic equation.  
     
     
         36 . The computer program product of  claim 35  wherein the second model includes a characterization table that includes the characteristic equation.  
     
     
         37 . The computer program product of  claim 35  wherein the second model is a static timing analysis model including the characteristic equation.  
     
     
         38 . The computer program product of  claim 35  wherein the computer application is processable by the computer for causing the computer to generate the second set by: 
 determining respective sets of constant elements of the characteristic equation in response to subsets of the first set; and  
 according to the characteristic equation, in response to the first condition, generating the second set including respective estimates of the operation in response to the sets of constant elements.  
 
     
     
         39 . The computer program product of  claim 38  wherein the computer application is processable by the computer for causing the computer to select the selected subset from among the subsets of the first set in response to the comparison, the comparison being a comparison between the first estimate and the estimates of the second set.  
     
     
         40 . The computer program product of  claim 39  wherein: 
 the subsets of the first set are respectively associated with the sets of constant elements, so the selected subset of the first set is associated with a particular set of constant elements;  
 the estimates of the second set are respectively associated with the sets of constant elements, so a particular estimate of the second set is associated with the particular set of constant elements; and  
 among the estimates of the second set, the particular estimate is closest to the first estimate.  
 
     
     
         41 . The computer program product of  claim 33  wherein the operation is a response time of the circuitry.  
     
     
         42 . The computer program product of  claim 33  wherein the operation is a propagation delay of the circuitry.  
     
     
         43 . The computer program product of  claim 33  wherein the conditions include at least two types of conditions.  
     
     
         44 . The computer program product of  claim 33  wherein the conditions include at least three types of conditions.  
     
     
         45 . The computer program product of  claim 33  wherein the conditions include capacitive loadings of the circuitry.  
     
     
         46 . The computer program product of  claim 33  wherein the conditions include input transition times of the circuitry.  
     
     
         47 . The computer program product of  claim 46  wherein the conditions include at least two types of input transition times of the circuitry.  
     
     
         48 . The computer program product of  claim 33  wherein the circuitry is integrated circuitry.