| 摘要 |
PROBLEM TO BE SOLVED: To detect short circuiting between bundled terminal groups or multiple troubles therebetween, even when those exist, and to allow a stable test even when input output terminals are bundled. SOLUTION: An LSI 1 has bidirectional (interactive) buffers 20a-20c connected to a boundary scan circuit 12, and the boundary scan circuit 12 has asynchronous setting circuits 7a-7c for setting each of the bidirectional buffers 20a-20c asynchronously in an input mode or an output mode. At first, the bidirectional buffers 20a-20c are asynchronously set evenly to an output mode to detect logic trouble, the input output terminals I01-I03 connected to the bidirectional buffers 20a-20c are bundled when no logic trouble exists, the bidirectional buffers 20a-20c are asynchronously fixed evenly, a setting value for setting a desired enabling condition in the boundary scan circuit 12, the even input mode is released thereafter asynchronously, and a DC test is executed by the boundary scan circuit 12. COPYRIGHT: (C)2007,JPO&INPIT
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