| 摘要 |
PURPOSE: To read identification characteristics even if a circuit is encapsulated in a case by connecting each programmable element to one common conductor on one hand and connecting it to the drain of a transistor on the other hand. CONSTITUTION: A circuit device comprises n programmable elements F1,..., Fn, one n-stage series - parallel shift registers SR, and n transistors T. While the programmable elements F1,..., Fn are connected to an assembly conductor DO that forms a data output terminal, it is connected to the drain of the transistors T. Then, the source of the transistors T is connected to a first supply potential VSS, and a gate is connected to one of parallel output terminals O1,..., On of the series - parallel shift register SR, thus reading a number of identification characteristics with the minimum occupation area. |
