| 摘要 |
<p>PURPOSE:To simplify a test pattern by using a load transistor or resistor for test, which removes the open defect of parallel transistors forming a NOR gate or a NAND gate for cosntituting a decoder. CONSTITUTION:There is a decoder circuit which is constituted of a NOR gate, wherein a load MOS transistor 29 that is controlled with a test signal T is arranged. When one of transistors 21-24 becomes defective by opening, the output Oi becomes the low level intrinsically in the conventional device because of the defective transistor. In this testing circuit, however, the output Oi becomes the high level with the load transistor 29, and the defect is judged in the test.</p> |
