| 摘要 |
PURPOSE:To improve the facility of test and diagnosis without increasing the number of pins extremely by dividing a logic circuit block to plural subblocks and providing selectors at division points to constitute bypass circuits of subblocks. CONSTITUTION:Selectors 4 are provided just after subblocks 1 divided properly in consideration of test and diagnosis, and output signal lines and input signal lines of subblocks 1 are connected, and signal selecting pins 5 connected to selectors 4 are controlled switch signal lines. Selecting pins 5 are so controlled to select input signal line sides of subblocks 1, thereby constituting bypass circuits of subblocks 1. In case of test and diagnosis, selecting pins 5 are controlled properly to select one subblock 1, and test and diagnosis in subblock units are performed. |
