| 摘要 |
PROBLEM TO BE SOLVED: To provide a connection test means which is inexpensive and eliminates extra signal delay concerning the boundary scan circuit of a boundary scan adaptive device connected to a boundary scan non-adaptive device. SOLUTION: Buffers 7 to 10 with an output enable control function is disposed between an input/output pin of the boundary scan adaptive device 2 and an input/output pin of the boundary scan non-adaptive device 3 to control the output of the adaptive device 2. The output 13 of a boundary scan adaptive device 1 for testing is put to LO to control the outputs of the buffers 7 and 8 to enable so that the outputs 23 and 24 of the adaptive device 2 are connected to the inputs 13 and 14 of the adaptive device 1, thereby accomplishing the testing of the connection state of the outputs 23 and 24. |
