US4696006A
Expired / Lapsed
US
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Method of generating test patterns for logic network devices
Assignee: NEC Corp
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Filing: 1985-11-25
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Granted: 1987-09-22
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Expires: 2005-11-25
Abstract
Abstract Nodes and paths for connecting the nodes are used to form a model of at least one logic network. Next, all paths for connecting nodes in the logic network are traced, and the nodes and connecting path segments are sensitized and justified. The sensitizing patterns, when generating test patterns for a sequential circuit wherein the output is a function of a time sequence of inputs, may include a time sequence of sensitizing or input patterns for testing a single path through the network.
Inventors
- 👤 Masato Kawai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:47
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/28; G01R31/317; G01R31/3181; G01R31/3183; G01R31/318392
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
126 words
A method of testing a network, said network comprising a controllable node responsive to a given input pattern, an operator node for performing a predetermined function for the input pattern, an observable node for observing an output of the operator node and signal path segments for connecting the nodes, said method including the steps of: tracing a path from said observable node to said controllable node through operator node; determining a sensitizing condition for sensitizing said traced path; generating an input pattern sequence for sensitizing said traced path, said input pattern sequence comprising at least first and second input patterns provided at different times; applying said generated patterns to said network: and examining outputs of said network to determine the existence of faults in said network.
Claim 2
Independent Claim
126 words
A method of testing a network, said network comprising a controllable node responsive to a given input pattern, an operator node for performing a predetermined function for the input pattern, an observable node for observing an output of the operator node and signal path segments for connecting the nodes, said method including the steps of: tracing a path from said observable node to said controllable node through operator node; determining a sensitizing condition for sensitizing said traced path; generating an input pattern sequence for sensitizing said traced path, said input pattern sequence comprising at least first and second input patterns provided at different times; applying said generated patterns to said network: and examining outputs of said network to determine the existence of faults in said network.
Claim 3
Dependent Claim
55 words
A method according to claim 1, wherein said network includes means operable in response to a clock signal and said first and second input patterns are provided during first and second cycles of said clock signal with said second cycle being separated in time from said first cycle by at least one interventing clock pulse.
Claim 4
Dependent Claim
51 words
A method according to claim 1, wherein said network includes a plurality of controllable nodes, said method including tracing paths from said observable node to each of said controllable nodes until all possible paths between said observable and controllable nodes have been traced, and generating test patterns for each traced path.
Claim 5
Dependent Claim
86 words
A method according to claim 3, wherein for a traced path unaffected by sequential circuit components, said input information comprises a single input pattern, for a traced path including sequential circuit components, said input information comprises at least first and second input patterns provided at different times, and for a traced path which itself includes no sequential components but the sensitization of which requires the operation of a sequential circuit component, said input information comprises at least first and second input patterns provided at different times.
Claim 6
Dependent Claim
15 words
A method according to claim 3, wherein each input pattern comprises a plurality of bits.
Claim 7
Dependent Claim
173 words
A method according to claim 1, wherein said network includes a plurality of observable, operator and controllable nodes, and said tracing step comprises: A. tracing a path from an observable node to a controllable node; B. returning toward said observable node to the most recent previous operator node in said traced path and determining if any untraced paths exist between said previous operator node and any of said controllable nodes; C. if an untraced path exists between said previous operator node and a controllable node, tracing said untraced path; D. if no untraced path exists between said previous operator node and a controllable node, returning toward said observable node to the next most recent previous node in said path between said observable node and the last controllable node to which a path has been traced; E. repeating steps B-D until all paths from said observable node to any controllable nodes have been traced; F. selecting a further observable node; and G. repeating steps A-F until all paths in said network have been traced.
Claim 8
Dependent Claim
15 words
A method according to claim 1, wherein each input pattern comprises a plurality of bits.
Claim 9
Independent Claim
110 words
A method of generating input patterns for testing a network, said network comprising a controllable node responsive to a given input pattern, an operator node for performing a predetermined function for the input pattern, an observable node for observing an output of the operator node and signal path segments for connecting the nodes, said method including the steps of: tracing a path from said observable node to said controllable node through said operator node; determining a sensitizing condition for sensitizing said traced path; and generating an input pattern sequence for sensitizing said traced path, said input pattern sequence comprising at least first and second input patterns provided at different times.
Claim 10
Independent Claim
110 words
A method of generating input patterns for testing a network, said network comprising a controllable node responsive to a given input pattern, an operator node for performing a predetermined function for the input pattern, an observable node for observing an output of the operator node and signal path segments for connecting the nodes, said method including the steps of: tracing a path from said observable node to said controllable node through said operator node; determining a sensitizing condition for sensitizing said traced path; and generating an input pattern sequence for sensitizing said traced path, said input pattern sequence comprising at least first and second input patterns provided at different times.
Claim 11
Dependent Claim
55 words
A method according to claim 8, wherein said network includes means operable in response to a clock signal and said first and second input patterns are provided during first and second cycles of said clock signal with said second cycle being separated in time from said first cycle by at least one intervening clock pulse.
Claim 12
Dependent Claim
51 words
A method according to claim 8, wherein said network includes a plurality of controllable nodes, said method including tracing paths from said observable node to each of said controllable nodes until all possible paths between said observable and controllable nodes have been traced, and generating test patterns for each traced path.
Claim 13
Dependent Claim
86 words
A method according to claim 10, wherein for a traced path unaffected by sequential circuit components, said input information comprises a single input pattern, for a traced path including sequential circuit components, said input information comprises at least first and second input patterns provided at different times, and for a traced path which itself includes no sequential components but the sensitization of which requires the operation of a sequential circuit component, said input information comprises at least first and second input patterns provided at different times.
Claim 14
Dependent Claim
173 words
A method according to claim 10 wherein said network includes a plurality of observable, operator and controllable nodes, and said tracing step comprises: A. tracing a path from an observable node to a controllable node; B. returning toward said observable node to the most recent previous operator node in said traced path and determining if any untraced paths exist between said previous operator node and any of said controllable nodes; C. if an untraced path exists between said previous operator node and a controllable node, tracing said untraced path; D. if no untraced path exists between said previous operator node and a controllable node, returning toward said observable node to the next most recent previous node in said path between said observable node and the last controllable node to which a path has been traced; E. repeating steps B-D until all paths from said observable node to any controllable nodes have been traced; F. selecting a further observable node; and G. repeating steps A-F until all paths in said network have been traced.
Claim 15
Dependent Claim
15 words
A method according to claim 8, wherein each input pattern comprises a plurality of bits.
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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) | 1990-09-21 | 1991-03-23 | 1991-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-09-21 | 1995-03-23 | 1995-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-09-21 | 1999-03-23 | 1999-09-22 | $7700.00 | Window Closed / Lapsed |