| 摘要 |
PURPOSE:To enable to discriminate the defect in either of input and output section or external unit easily, and to diagnose the input and output section, by adding the high speed selector switch, level converter, and pattern generator and test input area. CONSTITUTION:When the failure diagnosis of input and output section 5 is desired, high speed switches 23, 24, 26, 27 are connected to T1, T2, T3, T4 side. Thus, the signal from the pattern generator 22 is inputted to the test input area 29 via the output buffer 11, transistor 12, fuse 13, level converter 25, and input buffer 15. When the pattern generator 22 outputs ''0'' state, it is inputted to the ''0'' state area 30, and when the ''1'' state is outputted, it is inputted to the ''1'' area 31, thus the high speed selection switch E32 is selected. Thus, when the input and output section 5 is correctly operated, the content of the test areas 30, 31 are respectively ''0'' and ''1''. If different, the input and output circuit of the input and output point is in failure. |
