| 摘要 |
PURPOSE:To perform in a short time a test of an arbitrary logic circuit block by constituting the titled device so that a direction of a scan path can be switched from a scan-in terminal to a direction of a scan-out terminal, and to other direction than said direction. CONSTITUTION:In case of executing other test than that on a scan path 1, first of all, a data is shifted to the path 1 direction (X direction) by setting an INH signal 201 to '0', and thereafter, the data is shifted by using a scan clock SC 203, to the direction (Y direction) of other scan path 206 by setting the signal 201 to '1', and the data is set to a state storing circuit corresponding to one block of an internal logic circuit 2. Subsequently, the regular circuit operation is executed by an input line 204 and an output line 205 of the circuit 2, and a system clock CK 202, and thereafter, the data which is set to the state storing circuit is shifted to state storing circuits 11-1n on the path 1 by using the path 206. Thereafter, the signal 201 is returned to '0' and shifted to the direction of the path 1, scan-out is executed, and by comparing a result of output with an expected value, a test is executed.
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