US4386403A
Expired / Lapsed
US
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System and method for LSI circuit analysis
Assignee: International Business Machines Corp
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Filing: 1979-12-31
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Granted: 1983-05-31
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Expires: 1999-12-31
Abstract
Abstract A system and method for analysis of circuits which include a large number of circuit elements. Blocks of circuitry which define logical circuit functions such as gates and latches are set up as macromodels. Each macromodel need be represented in its full detail only once. Means are provided to recognize latency, or quiescence, of macromodels so that time may be saved in the circuit analysis when a macromodel is latent.
Inventors
- 👤 Hsueh Y. Hsieh
- 👤 Naguib B. G. Rabbat
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:26
CPC Classifications
G; G06; G06F; G06F30/00; G06F30/30; G06F30/36; G06F30/367
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
154 words
A system for performing a circuit analysis of a network, said system comprising: input means for receiving circuit data providing information as to the topology and parameters of the network to be analyzed; partitioning means for dividing said network into subnetworks; macromodeling means for assigning to each of a plurality of said subnetworks a macromodel circuit having nodes and branches; equation formulation means for providing for each of said macromodel circuits a respective set of circuit equations including specification of internal relationships and effects of external stimuli; initialization means for providing the initial voltage and current conditions of a plurality of said nodes and branches of each of said macromodel circuits; circuit analysis means for solving said sets of circuit equations for a predetermined instant in time; and means for incrementing said time repeatedly and for activating said circuit analysis means after each increment for solving said sets of equations for each time increment.
Claim 2
Independent Claim
154 words
A system for performing a circuit analysis of a network, said system comprising: input means for receiving circuit data providing information as to the topology and parameters of the network to be analyzed; partitioning means for dividing said network into subnetworks; macromodeling means for assigning to each of a plurality of said subnetworks a macromodel circuit having nodes and branches; equation formulation means for providing for each of said macromodel circuits a respective set of circuit equations including specification of internal relationships and effects of external stimuli; initialization means for providing the initial voltage and current conditions of a plurality of said nodes and branches of each of said macromodel circuits; circuit analysis means for solving said sets of circuit equations for a predetermined instant in time; and means for incrementing said time repeatedly and for activating said circuit analysis means after each increment for solving said sets of equations for each time increment.
Claim 3
Dependent Claim
68 words
The system of claim 1 further including: latency detection means for signalling that successive solutions in time of the set of circuit equations for a particular macromodel circuit have varied by less than a predetermined amount; and means responsive to said signal to inhibit said circuit analysis means for solving the set of circuit equations related to said particular macromodel circuit until the occurrence of a predefined condition.
Claim 4
Dependent Claim
21 words
The system of claim 2 wherein said predefined condition is a change in the external stimuli related to said macromodel circuit.
Claim 5
Dependent Claim
22 words
The system of claim 1 or claim 3 wherein: at least one of said macromodel circuits includes within it another macromodel circuit.
Claim 6
Dependent Claim
166 words
The system of claim 1 or claim 3 wherein said circuit analysis means includes: first inter connection description means describing a first relationship between a first parameter of a first macromodel and a second parameter of a second macromodel; second interconnection description means describing a second relationship between said first parameter and said second parameter; prediction means for selecting a predicted value for said first parameter; computation means related to said first interconnection description means for generating, based upon said predicted value, a first computed value for said second parameter; further computation means related to said second interconnection description means for generating based upon said first computed value, a second computed value for said first parameter; means for comparing said predicted value with said second computed value and for producing an indication of the magnitude of the difference between them; and means responsive to said indication to cause said prediction means to select another predicted value if said magnitude of the difference exceeds a predetermined amount.
Claim 7
Independent Claim
131 words
A method for performing a circuit analysis of a network, said method comprising: receiving circuit data providing information as to the topology and parameters of the network to be analyzed; partitioning said network into subnetworks; assigning to each of a plurality of said subnetworks a macromodel circuit having nodes and branches; providing for each of said macromodel circuits a respective set of circuit equations including specification of internal relationships and effects of external stimuli; providing the initial voltage and current conditions of a plurality of said nodes and branches of each of said macromodel circuits; solving said sets of circuit equations for a predetermined instant in time; and incrementing said time repeatedly and returning to said solving step after each increment to solve said sets of equations for each time increment.
Claim 8
Independent Claim
131 words
A method for performing a circuit analysis of a network, said method comprising: receiving circuit data providing information as to the topology and parameters of the network to be analyzed; partitioning said network into subnetworks; assigning to each of a plurality of said subnetworks a macromodel circuit having nodes and branches; providing for each of said macromodel circuits a respective set of circuit equations including specification of internal relationships and effects of external stimuli; providing the initial voltage and current conditions of a plurality of said nodes and branches of each of said macromodel circuits; solving said sets of circuit equations for a predetermined instant in time; and incrementing said time repeatedly and returning to said solving step after each increment to solve said sets of equations for each time increment.
Claim 9
Dependent Claim
61 words
The method of claim 6 further including: detecting when successive solutions in time of the set of circuit equations for a particular macromodel circuit have varied by less than a predetermined amount; and in response to said detecting step, inhibiting the solving of the set of circuit equations related to said particular macromodel circuit until the occurrence of a predefined condition.
Claim 10
Dependent Claim
21 words
The method of claim 7 wherein said predefined condition is a change in the external stimuli related to said macromodel circuit.
Claim 11
Dependent Claim
126 words
The method of claim 6 or claim 8 wherein said solving step includes: describing a first relationship between a first parameter of a first macromodel and a second parameter of a second macromodel; describing a second relationship between said first parameter and said second parameter; selecting a predicted value for said first parameter; generating, based upon said first relationship and said predicted value, a first computed value for said second parameter; generating, based upon said second relationship and said first computed value, a second computed value for said first parameter; comparing said predicted value with said second computed value and producing an indication of the magnitude of the difference between them; and selecting another predicted value if said magnitude of the difference exceeds a predetermined amount.
References Cited (Backward Citations)
US3653072A
Cited
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