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US5946475A
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Method for performing transistor-level static timing analysis of a logic circuit
Assignee: International Business Machines Corp
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Filing: 1997-01-21
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Granted: 1999-08-31
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Expires: 2017-01-21
Abstract
Abstract A method is provided for statically computing delays for transistor-level logic circuits which have input signal dependencies. This methodology may be implemented in transistor-level static timing analysis tools which compute delays of blocks or subcircuits that correspond to channel-connected components of transistors.
Inventors
- 👤 Timothy Michael Burks
- 👤 Robert Edward Mains
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 03:21
CPC Classifications
G; G06; G06F; G06F30/00; G06F30/30; G06F30/32; G06F30/33
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
88 words
A method for performing timing analysis of a logic circuit, comprising the steps of: identifying an input signal transition and an output signal transition of the logic circuit; computing a sensitization condition corresponding to the input signal transition and the output signal transition using the sensitization condition to identify a worst case condition; and generating a simulation pattern which enables an output of the logic circuit to transition from a first logic state to a second logic state by applying a generated signal which corresponds the sensitization condition.
Claim 2
Independent Claim
88 words
A method for performing timing analysis of a logic circuit, comprising the steps of: identifying an input signal transition and an output signal transition of the logic circuit; computing a sensitization condition corresponding to the input signal transition and the output signal transition using the sensitization condition to identify a worst case condition; and generating a simulation pattern which enables an output of the logic circuit to transition from a first logic state to a second logic state by applying a generated signal which corresponds the sensitization condition.
Claim 3
Dependent Claim
29 words
The method of claim 1, further comprising the step of: simulating a function of the logic circuit by providing the simulation pattern to an input of the logic circuit.
Claim 4
Dependent Claim
24 words
The method of claim 2, further comprising the step of: measuring a result of the simulation pattern on the input of the logic circuit.
Claim 5
Dependent Claim
26 words
The method of claim 3 wherein the result indicates a delay associated with the provision of the input signal and the output of the logic circuit.
Claim 6
Dependent Claim
70 words
The method of claim 3, further comprising the steps of: determining whether the result is less than a previous result of a previous simulation pattern on the logic circuit; storing the previous result of the previous simulation pattern in a memory when the previous result is greater than the result; and storing the result of the simulation pattern in the memory when the previous result is less than the result.
Claim 7
Dependent Claim
73 words
The method of claim 3, further comprising the steps of: determining whether the result is less than a previous result of a previous simulation pattern on the node of the clock circuit; storing the previous result of the previous simulation pattern in a memory when the previous result is less than the result; and storing the result of the simulation pattern in the memory when the previous result is greater than the result.
Claim 8
Dependent Claim
50 words
The method of claim 1 wherein the step of computing the sensitization condition, further comprises the step of: determining when the output of the logic circuit will not be in an undesired logic state after the input signal has transitioned from the first logic state to the second logic state.
Claim 9
Dependent Claim
49 words
The method of claim 1 wherein the step of computing the sensitization condition, further comprises the step of: determining when the output of the logic circuit will be in a desired logic state before the input signal has transitioned from the first logic state to the second logic state.
Claim 10
Dependent Claim
49 words
The method of claim 1 wherein a step of computing the sensitization condition, further comprises the step of: determining when the output of the logic circuit will be in a desired logic state after an input signal has transitioned from a first logic state to a second logic state.
Claim 11
Dependent Claim
49 words
The method of claim 9 wherein the step of computing the sensitization condition, further comprises the step of: determining when output of the logic circuit will not be in an undesired logic state after the input signal has transitioned from the first logic state to the second logic state.
Claim 12
Dependent Claim
82 words
A data processing system, comprising: a memory for storing a model of a logic circuit; and a data processor for computing a first signal being provided to the logic circuit and a second signal being output by the logic circuit in response to the first signal, the data processor computing the delay by determining a sensitization condition corresponding to the first signal and applying a generated signal which has the sensitization condition corresponding to the first signal provided to the logic circuit.
Claim 13
Dependent Claim
82 words
A data processing system, comprising: a memory for storing a model of a logic circuit; and a data processor for computing a first signal being provided to the logic circuit and a second signal being output by the logic circuit in response to the first signal, the data processor computing the delay by determining a sensitization condition corresponding to the first signal and applying a generated signal which has the sensitization condition corresponding to the first signal provided to the logic circuit.
Claim 14
Dependent Claim
42 words
The data processing system of claim 11 wherein the sensitization condition determines when the output of the logic circuit will be in a desired logic state after an input signal has transitioned from a first logic level to a second logic level.
Claim 15
Dependent Claim
41 words
The data processing system of claim 11 wherein the sensitization condition determines when output of the logic circuit will be in a desired logic state before the input signal has transitioned from the first logic level to the second logic level.
Claim 16
Dependent Claim
42 words
The data processing system of claim 11 wherein the sensitization condition determines when output of the logic circuit will not be in an undesired logic state after the input signal has transitioned from the first logic level to the second logic level.
Claim 17
Dependent Claim
110 words
A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform method steps for performing a timing analysis of a logic circuit, said method steps comprising: identifying an input signal transition and an output signal transition of the logic circuit; computing a sensitization condition corresponding to the input signal transition and the output signal transition; using the sensitization condition to identify a worst case condition; and generating a simulation pattern which enables an output of the logic circuit to transition from a first logic state to a second logic state by applying a generated signal which corresponds to the sensitization condition.
Claim 18
Dependent Claim
110 words
A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform method steps for performing a timing analysis of a logic circuit, said method steps comprising: identifying an input signal transition and an output signal transition of the logic circuit; computing a sensitization condition corresponding to the input signal transition and the output signal transition; using the sensitization condition to identify a worst case condition; and generating a simulation pattern which enables an output of the logic circuit to transition from a first logic state to a second logic state by applying a generated signal which corresponds to the sensitization condition.
Claim 19
Dependent Claim
75 words
The program storage device of claim 15 embodying the program of instructions executable by the machine to perform method steps, said method steps further comprising a step of: simulating a function of the logic circuit by providing the simulation pattern to an input of the logic circuit, wherein a result indicates a delay associated with the provision of a first one of a plurality of input signals and the output generated by the logic circuit.
Claim 20
Dependent Claim
59 words
The program storage device of claim 15 embodying the program of instructions executable by the machine to perform method steps, said method steps further comprising a step of: determining when the output of the logic circuit will be in a desired logic state after an input signal has transitioned from a first logic state to a second logic state.
Claim 21
Dependent Claim
60 words
The program storage device of claim 15 embodying the program of instructions executable by the machine to perform method steps, said method steps further comprising a step of: determining when the output of the logic circuit will not be in an undesired logic state after the input signal has transitioned from the first logic state to the second logic state.
Claim 22
Dependent Claim
59 words
The program storage device of claim 18 embodying the program of instructions executable by the machine to perform method steps, said method steps further comprising a step of: determining when the output of the logic circuit will be in a desired logic state before the input signal has transitioned from the first logic state to the second logic state.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-08-30 | 2003-03-01 | 2003-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-08-30 | 2007-03-01 | 2007-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-08-30 | 2011-03-01 | 2011-08-31 | $7700.00 | Window Closed / Lapsed |