Test apparatus for generating reference scan chain test data and test system
First Claim
1. A test system comprising:
- a test pattern generator configured to;
receive an input scan chain;
generate a modified input scan chain by replacing a first predefined number of start bits of the input scan chain with a predefined start bit sequence; and
provide the modified input scan chain to a device under test (DUT); and
an output data modifier and configured to;
receive an output scan chain that is generated by the DUT in response to the modified input scan chain;
generate a modified output scan chain by replacing a second predefined number of end bits of the output scan chain with a predefined end bit sequence; and
obtain first reference scan chain test data based on the modified output scan chain.
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Accused Products
Abstract
A test apparatus for generating reference scan chain test data comprises a test pattern generator and an output data modifier. The test pattern generator modifies a scan chain test input bit sequence by replacing a predefined number of start bits of the scan chain test input bit sequence by a predefined start bit sequence. Further, the test pattern generator provides the modified scan chain test input bit sequence to a device under test. The output data modifier modifies a scan chain test output bit sequence received from the device under test and caused by the modified scan chain test input bit sequence. The scan chain test output bit sequence is modified by replacing a predefined number of end bits of the scan chain test output bit sequence by a predefined end bit sequence to obtain the reference scan chain test data.
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Citations
21 Claims
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1. A test system comprising:
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a test pattern generator configured to;
receive an input scan chain;generate a modified input scan chain by replacing a first predefined number of start bits of the input scan chain with a predefined start bit sequence; and
provide the modified input scan chain to a device under test (DUT); andan output data modifier and configured to;
receive an output scan chain that is generated by the DUT in response to the modified input scan chain;
generate a modified output scan chain by replacing a second predefined number of end bits of the output scan chain with a predefined end bit sequence; and
obtain first reference scan chain test data based on the modified output scan chain. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A circuit for generating reference scan chain test data, the circuit comprising:
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a test pattern generator configured to;
receive an input scan chain;
generate a modified scan chain test input bit by replacing a first predefined number of start bits of the input scan chain with a predefined start bit sequence; and
provide the modified input scan chain to a device under test (DUT); andan output data modifier coupled to the test pattern generator and configured to; receive an output scan chain that is generated by the DUT in response to the modified input scan chain;
generate a modified output scan chain by replacing a second predefined number of end bits of the output scan chain with a predefined end bit sequence; and
obtain first reference scan chain test data based on the modified output scan chain.
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19. A method of determining a failure position and failure type of a scan chain, the method comprising:
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receiving a first input scan chain at a test pattern generator; generating a first modified input scan chain at a test pattern generator by replacing a first predefined number of start bits of the first input scan chain with a predefined start bit sequence; providing the first modified input scan chain from the test pattern generator to a device under test (DUT), wherein the DUT is configured to generate a first output scan chain in response, generating a first modified output scan chain at an output data modifier by replacing a second predefined number of end bits of first the output scan chain with a predefined end bit sequence; and obtaining first reference scan chain test data based on the first modified output scan chain at said output data modifier. - View Dependent Claims (20, 21)
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Specification