| 摘要 |
PURPOSE: A semiconductor IC device including a test point is provided to improve controllability and observability as main elements of testability and minimize an overhead due to insertion of test points. CONSTITUTION: A semiconductor IC device(400) is formed with a scan cell unit(430) including the first scan block(431) for performing a scan operation and the second scan block(432) for inserting the test point such as an observing point(OP) and a controlling point(CP). A data input terminal(D) of each scan cell(432_1, 432_2,... 432_m, 432_M+1...) of the second scan cell block(432) is connected with one input terminal of an AND gate. The other input terminal of the AND gate is connected with a RESET signal. An output signal of the AND gate is used as a selection signal for the first and the second multiplexers(440,450). In the semiconductor IC device(400), the number of pin can be reduced and test points are inserted by using a part(432) of scan cells(430) of an existing circuit instead of exclusive scan cells.
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