| 摘要 |
PURPOSE: To divert from a printed circuit board and a diagnosing software of a register definition if the number and the positions of placing logic integrated circuits in which logic packages of a plurality of types having scan paths are placed on the board are altered and to reduce uninspected circuits as much as possible at the time of solely testing even in the logic packages of any type. CONSTITUTION: The logic integrated circuit comprises a plurality of scan path input circuits 111 to 114, open checking circuits 115 to 117 for deciding whether logic binary signals are input to the scan path input circuits 111 to 114 or input open states, a switching unit for selecting which of a plurality of the scan path inputs is transferred to a logic unit, shift registers 121 to 123 disposed so that the number of total flip-flops on the paths becomes the same even if any scan path input is selected, and a forcible switching instructing circuit 53 for forcibly switching the switching unit. |
