Method and apparatus for selecting test sequences

• US 6,385,741 B1
• Filed: 05/26/1999
• Issued: 05/07/2002
• Est. Priority Date: 10/05/1998
• Status: Expired due to Term

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Nakamura, Mitsuhiro
• Primary Examiner(s): Baderman, S.
• Application Number:
  US09/320,338
• Time in Patent Office: 1,077 Days
• Field of Search: 714/38-39, 714/37, 714/33-36, 714/51, 717/4, 717/9
• US Class Current: 714/38.1
• CPC Class Codes: G06F 11/263 Generation of test inputs, e.g. test vectors, patterns or sequences ; with adaptation of the tested hardware for testability with external testers

Abstract

A method and an apparatus for selecting test sequences that comprises preparing tree-structured state transition data associated with state transition weights from state transition data, extracting test sequences from the tree-structured state transition data, and repeating processes of determining averaged weight for each of the test sequences, selecting a test sequence by which the average is maximum, and decrementing the weights contained in the selected test sequence by one unit to prioritize the test sequences.

Claims

1. A method for selecting test sequences comprising;

a first step for preparing tree-structured state transition data associated with state transition weights from state transition data;

a second step for extracting test sequences from the tree-structured state transition data; and

a third step for repeating processes of determining averaged weight for each of the test sequences, selecting a test sequence by which the average is maximum, and decrementing the weights contained in the selected test sequence by one unit to prioritize the test sequences.

2. The method for selecting test sequences as claimed in claim 1 wherein the third step further comprises a prioritizing step for retaining data indicating untested/tested state transitions and lowering the priority of the selected test sequence if all of the state transitions contained therein have been tested.

3. The method for selecting test sequences as claimed in claim 1, further comprising a fourth step for sequentially outputting a designated number of test sequences in order of higher priority.

4. The method for selecting test sequences as claimed in claim 3, wherein if there are test sequences containing untested state transitions among the test sequences which are not included in the output by the fourth step, the method further comprises a step for outputting the test sequences with warning messages.

5. The method for selecting test sequences as claimed in claim 1, further comprising a fourth step for sequentially outputting only a number of test sequences containing untested state transitions in order of higher priority.

6. A method for selecting test sequences comprising;

a first step for preparing tree-structured state transition data associated with state transition weights from state transition data;

a second step for extracting test sequences from the tree-structured state transition data; and

a third step for retaining data indicating untested/tested state transitions to prioritize the test sequences based on the number of the untested state transitions.

7. The method for selecting test sequences as claimed in claim 6, wherein if there are a plurality of test sequences containing the same number of the untested state transitions, the third step further comprises a step for prioritizing the test sequences based on the total of the weights.

8. An apparatus for selecting test sequences comprising;

tree-structure transformation means for preparing tree-structured state transition data associated with state transition weights from state transition data;

test sequence extraction means for extracting test sequences from the tree-structured state transition data; and

prioritizing means for repeating processes of determining averaged weight for each of the test sequences, selecting a test sequence by which the average is maximum, and decrementing the weights contained in the selected test sequence by one unit to prioritize the test sequences.

9. The apparatus for selecting test sequences as claimed in claim 8 wherein the prioritizing means further comprise means for retaining data indicating untested/tested state transitions and lowering the priority of the selected test sequence if all of the state transitions contained therein have been tested.

10. The apparatus for selecting test sequences as claimed in claim 8, further comprising output means for sequentially outputting a designated number of test sequences in order of higher priority.

11. The apparatus for selecting test sequences as claimed in claim 10, wherein if there are test sequences containing untested state transitions among the test sequences which are not included in the output by the output means, the apparatus further comprises means for outputting the test sequences with warning messages.

12. The apparatus for selecting test sequences as claimed in claim 8, further comprising means for sequentially outputting only a number of test sequences containing untested state transitions in order of higher priority.

13. An apparatus for selecting test sequences comprising;

tree-structure transformation means for preparing tree-structured state transition data associated with state transition weights from state transition data;

test sequence extraction means for extracting test sequences from the tree-structured state transition data; and

prioritizing means for retaining data indicating untested/tested state transitions to prioritize the test sequences based on the number of the untested state transitions.

14. The apparatus for selecting test sequences as claimed in claim 13, wherein if there are a plurality of test sequences containing the same number of the untested state transitions, the prioritizing means further comprise means for prioritizing the test sequences based on the total of the weights.