Method and apparatus for locating faults in electronic units
First Claim
1. A computer based method of characterizing an electronic circuit having a plurality of interconnected electronic circuit components, comprising the steps of:
- storing in said computer, a representation of said electronic circuit including said plurality of interconnected electronic circuit components;
determining, for at least one of said electronic circuit components, incremental changes in selected outputs thereof which result from incremental changes in selected inputs thereto; and
storing in said computer, for said at least one of said electronic circuit components, said determined incremental changes in selected outputs thereof which result from said incremental changes in selected inputs thereto;
wherein said at least one of said electronic circuit components include primitive circuit components, andwherein said at least one of said electronic circuit components further include intermediate and high level circuit components.
3 Assignments
0 Petitions
Accused Products
Abstract
An artificial intelligence based method and apparatus for locating faults in electronic units includes a technique for modelling electronic units in terms of behavioral constraints. Behavioral constraints model circuit components in terms of changes in outputs thereof which result from changes in inputs thereto. These changes, referred to as "phase changes" may be supplemented by gain and compliance constraints to model an electronic unit at all functional abstraction or hierarchical decomposition levels thereof. In addition to providing a universal modelling scheme, behavioral constraint relationships provide a highly accurate indication of subtle changes in a circuit, for accurate fault location or troubleshooting.
Troubleshooting takes place by applying a predetermined search strategy on the electronic unit which is represented by behavioral constraints. The search strategy begins with a top down search. When a faulty block is found, the search moves down one functional abstraction level and searches the next lower level block having an output corresponding to the output of the higher level block. If the next lower level block is not defective, adjacent blocks at the next lower level are searched.
Testing of the electronic unit is begun according to the functional test plan specified for the unit. Each functional test in the functional test plan is associated with one or more blocks at a functional abstraction level. When a functional test fails, troubleshooting begins at the block and functional abstraction level corresponding to the failed functional test.
76 Citations
114 Claims
-
1. A computer based method of characterizing an electronic circuit having a plurality of interconnected electronic circuit components, comprising the steps of:
-
storing in said computer, a representation of said electronic circuit including said plurality of interconnected electronic circuit components; determining, for at least one of said electronic circuit components, incremental changes in selected outputs thereof which result from incremental changes in selected inputs thereto; and storing in said computer, for said at least one of said electronic circuit components, said determined incremental changes in selected outputs thereof which result from said incremental changes in selected inputs thereto; wherein said at least one of said electronic circuit components include primitive circuit components, and wherein said at least one of said electronic circuit components further include intermediate and high level circuit components. - View Dependent Claims (2)
-
-
3. A computer based method of characterizing an electronic circuit having a plurality of interconnected electronic circuit components, comprising the steps of:
-
storing in said computer, a representation of said electronic circuit including said plurality of interconnected electronic circuit components; determining, for at least one of said electronic circuit components, incremental changes in selected outputs thereof which result from incremental changes in selected inputs thereto; and storing in said computer, for said at least one of said electronic circuit components, said determined incremental changes in selected outputs thereof which result from said incremental changes in selected inputs thereto; wherein said incremental changes in selected outputs thereof which result from incremental changes in selected inputs thereto comprise a series of IF-THEN statements in the form IF (input change 1, input change 2 . . . input change n) THEN (output change 1, output change 2 . . . output change n), wherein input change 1, input change 2 . . . input change n represent said incremental changes in said selected inputs and output change 1, output change 2 . . . output change n represent said incremental changes in said selected outputs.
-
-
4. A computer based method of characterizing an electronic circuit having a plurality of interconnected electronic circuit components, comprising the steps of:
-
storing in said computer, a representation of said electronic circuit including said plurality of interconnected electronic circuit components; determining, for at least one of said electronic circuit components, incremental changes in selected outputs thereof which result from incremental changes in selected inputs thereto; and storing in said computer, for said at least one of said electronic circuit components, said determined incremental changes in selected outputs thereof which result from said incremental changes in selected inputs thereto; wherein said incremental changes in selected outputs thereof which result from incremental changes in selected inputs thereto comprise a series of statements in the form (input 1, input 2 . . . input n) IN PHASE/OUT OF PHASE (output 1, output 2 . . . output n), where input 1, input 2 . . . input n represent said selected inputs and output 1, output 2 . . . output n represent said selected outputs.
-
-
5. A computer based method of characterizing an electronic circuit having a plurality of interconnected electronic circuit components, comprising the steps of:
-
storing in said computer, a representation of said electronic circuit including said plurality of interconnected electronic circuit components; determining, for at least one of said electronic circuit components, incremental changes in selected outputs thereof which result from incremental changes in selected inputs thereto; storing in said computer, for said at least one of said electronic circuit components, said determined incremental changes in selected outputs thereof which result from said incremental changes in selected inputs thereto; and storing in said computer, for said at least one of said electronic circuit components at least one gain between selected outputs thereof and selected inputs thereof.
-
-
6. A computer based method of characterizing an electronic circuit having a plurality of interconnected electronic circuit components, comprising the steps of:
-
storing in said computer, a representation of said electronic circuit including said plurality of interconnected electronic circuit components; determining, for at least one of said electronic circuit components, incremental changes in selected outputs thereof which result from incremental changes in selected inputs thereto; storing in said computer, for said at least one of said electronic circuit components, said determined incremental changes in selected outputs thereof which result from said incremental changes in selected inputs thereto; and storing in said computer, for at least one of said electronic circuit components at least one compliance thereof. - View Dependent Claims (7, 8)
-
-
9. A computer based model for circuit components comprising incremental changes in selected outputs of said circuit components which result from incremental changes in selected inputs to said circuit components, said incremental changes in selected outputs and said incremental changes in selected inputs being stored in a computer;
- wherein said circuit components include primitive circuit components, and wherein said circuit components further include intermediate and high level circuit components.
- View Dependent Claims (10)
-
11. A computer based model for circuit components comprising incremental changes in selected outputs of said circuit components which result from incremental changes in selected inputs to said circuit components, said incremental changes in selected outputs and said incremental changes in selected inputs being stored in a computer;
- wherein said incremental changes in selected outputs which result from incremental changes in selected inputs comprise a series of IF-THEN statements in the form IF (input change 1, input change 2 . . . input change n) THEN (output change 1, output change 2 . . . output change n), wherein input change 1, input change 2 . . . input change n represent said incremental changes in said selected inputs and output change 1, output change 2 . . . output change n represent said incremental changes in said selected outputs.
-
12. A computer based model for circuit components comprising incremental changes in selected outputs of said circuit components which result from incremental changes in selected inputs to said circuit components, said incremental changes in selected outputs and said incremental changes in selected inputs being stored in a computer;
- wherein said incremental changes in selected outputs which result from incremental changes in selected inputs thereto comprise a series of statements in the form (input 1, input 2 . . . input n) IN PHASE/OUT OF PHASE (output 1, output 2 . . . output n), where input 1, input 2 . . . input n represent said selected inputs and output 1, output 2 . . . output n represent said selected outputs.
-
13. A computer based model for circuit components comprising incremental changes in selected outputs of said circuit components which result from incremental changes in selected inputs to said circuit components, said incremental changes in selected outputs and said incremental changes in selected inputs being stored in a computer and further comprising gains between selected outputs thereof and selected inputs thereof.
- 14. A computer based model for circuit components comprising incremental changes in selected outputs of said circuit components which result from incremental changes in selected inputs to said circuit components, said incremental changes in selected outputs and said incremental changes in selected inputs being stored in computer and further comprising compliances thereof.
-
17. A computer based method of characterizing an electronic circuit, including a plurality of interconnected electronic components, comprising the steps of:
-
storing in said computer, a representation of said electronic circuit including said plurality of interconnected electronic components; and providing a library of models in said computer, said library of models comprising primitive, intermediate and high level models, each of said primitive, intermediate and high level models comprising incremental changes in selected outputs thereof which result from incremental changes in selected inputs thereto. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
-
-
28. A computer based apparatus for characterizing an electronic circuit including a plurality of interconnected electronic components, comprising:
-
means for storing in said computer, a representation of said electronic circuit including said plurality of interconnected electronic components; and a library of models in said computer, said library of models comprising primitive, intermediate and high level models, each of said primitive, intermediate and high level models comprising incremental changes in selected outputs thereof which result from incremental changes in selected inputs thereto. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36, 37, 38)
-
-
39. A computer based method for locating a fault in an electronic unit having a plurality of interconnected electronic components, comprising the steps of:
-
providing a library of models in said computer, said library of models comprising primitive, intermediate and high level models, each of said primitive, intermediate and high level models comprising incremental changes in selected outputs thereof which result from incremental changes in selected inputs thereto; associated selected ones of said primitive, intermediate and high level models to form a representation of said electronic unit; obtaining measurements of at least one of said plurality of interconnected electronic components; and
,employing said representation to determine whether said measurements of said at least one of said plurality of interconnected electronic components result from a malfunction of said at least one of said plurality of interconnected electronic components. - View Dependent Claims (40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51)
-
-
52. A computer based apparatus for locating a fault in an electronic unit having a plurality of interconnected electronic circuit components, comprising:
-
means for providing a library of models in said computer, said library of models comprising primitive, intermediate and high level models, each of said primitive, intermediate and high level models comprising incremental changes in selected outputs thereof which result from incremental changes in selected inputs thereto; means for associating selected ones of said primitive, intermediate and high level models to form a representation of said electronic unit; means for obtaining measurements of at least one of said plurality of interconnected electronic components; and
,means connected to said associating means, for determining whether said measurements of said at least one of said plurality of interconnected electronic components are as a result of a malfunction of said at least one of said plurality of interconnected electronic components. - View Dependent Claims (53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63)
-
-
64. A computer based method for isolating a fault in a unit under test, said unit under test comprising a plurality of interconnected electronic circuit components, comprising the steps of:
-
(a) providing in said computer a hierarchical decomposition of said unit under test, said hierarchical decomposition comprising a plurality of blocks each of which includes at least one input and at least one output, said blocks being arranged in a plurality of functional abstraction levels from low to high, each lowest functional abstraction level block corresponding to a respective one of said electronic circuit components, each higher functional abstraction level block including at least one next lower functional abstraction level block; (b) testing the electronic circuit components corresponding to a selected block to determine if said selected block is faulty; (c) if said selected block is faulty, testing the electronic circuit components corresponding to a first block in a next lower functional abstraction level from said selected block, said first block having an output which corresponds to an output of said selected block; (d) if the first block in said next lower functional abstraction level is not faulty, testing the electronic circuit components corresponding to an adjacent block in said next lower functional abstraction level; (e) repeating step (d) until a faulty next lower functional level block is found; (f) testing the electronic circuit components corresponding to a second block in a next lower functional abstraction level from said faulty next lower functional level block, said second block having an output which corresponds to an output of said faulty next lower functional abstraction level block; and (g) repeatedly performing steps (d), (e) and (f) until a faulty circuit component is found. - View Dependent Claims (65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84)
-
-
85. A computer system for isolating a fault in a unit under test, said unit under test comprising a plurality of interconnected electronic circuit components comprising:
-
means for storing in said computer a hierarchical decomposition of said unit under test, said hierarchical decomposition comprising a plurality of blocks each of which includes at least one input and at least one output, said blocks being arranged in a plurality of functional abstraction levels from low to high, each lowest functional abstraction level corresponding to a respective one of said electronic circuit components, each higher functional abstraction level block including at least one next lower functional abstraction level block; first means for directing testing of the electronic circuit components corresponding to a selected block to determine if said selected block is faulty; second means, connected to said first means, for directing testing the electronic circuit components corresponding to a first block in a next lower functional abstraction level from said selected block, said first block having an output which corresponds to an output of said selected block, if said first means indicates that said selected block is faulty; and third means, connected to said first means, for directing testing of the electronic circuit components corresponding to an adjacent block in said next lower functional abstraction level, if said first means indicates that said selected block is not faulty. - View Dependent Claims (86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102)
-
-
103. A computer based method for initiating automated troubleshooting of a unit under test, said unit under test comprising a plurality of interconnected electronic circuit components, said method comprising the steps of:
-
storing in said computer a hierarchical decomposition of said unit under test, said hierarchical decomposition comprising a plurality of blocks each of which at least one input and at least one output, said blocks being arranged in a plurality of functional abstraction levels from low to high, each lowest functional abstraction level block corresponding to a respective one of said electronic circuit components, each higher functional abstraction level block including at least one next lower functional abstraction level block; storing a functional test plan for the unit under test in said computer; associating a respective one of the functional tests in said functional test plan with at least one of said plurality of blocks being tested by the respective one of the functional tests; causing the functional tests specified in said functional test plan to be performed on said unit under test until one of the functional tests fails; and
,performing troubleshooting of said electronic circuit components corresponding to the block associated with the failed functional test. - View Dependent Claims (104, 105, 106)
-
-
107. A computer based apparatus for initiating automated troubleshooting of a unit under test, said unit under test comprising a plurality of interconnected electronic circuit components, said apparatus comprising:
-
means for storing in said computer a hierarchical decomposition of said unit under test, said hierarchical decomposition comprising a plurality of blocks each of which includes at least one input and at least one output, said blocks being arranged in a plurality of functional abstraction levels from low to high, each lowest functional abstraction level block corresponding to a respective one of said electronic circuit components, each higher functional abstraction level block including at least one next lower functional abstraction level block; means for storing a functional test plan for the unit under test in said computer; means for associating a respective one of the stored functional tests in said functional test plan with at least one of said plurality of blocks being tested by the respective one of the functional tests; means for causing the functional tests specified in said functional test plan to be performed on said unit under test until one of said functional tests fails; and
,means for initiating troubleshooting of said electronic circuit components corresponding to the block associated with the failed functional test. - View Dependent Claims (108, 109, 110)
-
-
111. A computer system for characterizing an electronic unit comprising a plurality of interconnected electronic circuit components, said computer system comprising:
-
a circuit knowledge base; an electronics knowledge base containing models of common electronic circuit components, said models comprising all of phase, gain and compliance limits; and a knowledge acquisition module connected to said circuit knowledge base and said electronics knowledge base, said knowledge acquisition module comprising; means for acquiring a representation of a schematic diagram of said electronic unit and placing said schematic diagram representation in said circuit knowledge base; means for generating a hierarchical decomposition of said electronic unit, said hierarchical decomposition comprising a plurality of blocks each of which includes at least one input and at least one output, said plurality of blocks being organized in a plurality of functional abstraction levels from low to high, the blocks in said lowest functional abstraction level corresponding to a respective one of said electronic circuit components, each higher functional abstraction level block including at least one next lower functional abstraction level block, each of said plurality of blocks corresponding to a model in said electronics database; and
,means for placing said hierarchical decomposition in said circuit knowledge base. - View Dependent Claims (112)
-
-
113. A computer system for troubleshooting an electronic unit comprising a plurality of interconnected electronic circuit components, said computer system comprising:
-
a circuit knowledge base, containing a hierarchical decomposition of said unit under test into a plurality of functional abstraction levels; an electronics knowledge base containing models of common electronic circuit components, said models comprising all of phase, gain and compliance limits; and a troubleshooting module comprising; means for storing in said circuit knowledge base a predetermined search strategy for searching said hierarchical decomposition; means for searching said hierarchical decomposition pursuant to said search strategy; and means for comparing measurements of said electronic circuit components with said models in said electronics knowledge base, to thereby identify a faulty one of said electronic circuit components. - View Dependent Claims (114)
-
Specification