Digital circuit unit testing system utilizing signature analysis
First Claim
1. A system for testing digital circuit units at the design speed of the circuit units, comprisinga first memory for storing a computer generated minimized set of optimum predetermined test patterns for application to a unit under test;
- a second memory for storing computer generated expected signature patterns which correspond to signature patterns that would be derived from a properly functioning unit under test in response to the predetermined test patterns;
a signature analyzer for deriving signature patterns from a unit under test in response to the application of said test patterns to said unit;
a comparator for comparing said derived signature patterns with said expected signature patterns and for providing an indication of the results of said comparison; and
means for addressing the first and second memories, the address means for addressing the first memory so as to apply said test patterns to said unit under test at a speed that corresponds to the design speed of the unit under test and the address means for addressing the second memory so as to apply said expected signature patterns to said comparator.
2 Assignments
0 Petitions
Accused Products
Abstract
A system for testing digital circuit units at the design speed of the circuit. A first memory stores a minimized set of optimum generated predetermined test patterns for application to a unit under test. A second memory stores expected signature patterns corresponding to signature patterns that are derived from the unit under test in response to the predetermined test patterns when the unit under test is functioning properly. A signature analyzer derives signature patterns from a unit under test in response to the application of the test patterns to the unit. A comparator compares the derived signature patterns with the expected signature patterns and provides an indication of the results of the comparison. A clock provides a clock signal having a pulse rate that corresponds to the design speed of the unit under test; and a sequential counter responds to said clock signal by providing a sequential count to the first memory for addressing the first memory at storage positions therein having addresses corresponding to the sequential count to cause the predetermined test patterns to be read from the first memory and applied to the unit at a speed that corresponds to the design speed of the unit under test. The testing system further includes a backtracing system for enabling determination of the location of faults in the unit under test.
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Citations
7 Claims
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1. A system for testing digital circuit units at the design speed of the circuit units, comprising
a first memory for storing a computer generated minimized set of optimum predetermined test patterns for application to a unit under test; -
a second memory for storing computer generated expected signature patterns which correspond to signature patterns that would be derived from a properly functioning unit under test in response to the predetermined test patterns; a signature analyzer for deriving signature patterns from a unit under test in response to the application of said test patterns to said unit; a comparator for comparing said derived signature patterns with said expected signature patterns and for providing an indication of the results of said comparison; and means for addressing the first and second memories, the address means for addressing the first memory so as to apply said test patterns to said unit under test at a speed that corresponds to the design speed of the unit under test and the address means for addressing the second memory so as to apply said expected signature patterns to said comparator. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification