| 摘要 |
PURPOSE:To make it possible to measure a monitoring element by utilizing an ordinary input/output pad, by imparting a signal, which is different from an ordinary signal, to an input/output terminal of a device. CONSTITUTION:At the time of normal operation, a control circuit 5 is made inactive. The output of an ordinary circuit 6 is present in a pad 4. In an monitor element measuring mode, a signal S1 (e.g., a voltage, which is higher than VCC, and the like), which is different from an ordinary signal, is applied to a pad 3. An operation suppressing signal S2 is imparted to the ordinary circuit 6. A control signal S3 is imparted to the gate of a transfer gate Ta. Then, the outputs of the ordinary circuit 6 turn OFF both Tb and Tc of an output driver circuit, and the pad 4 is isolated. Meanwhile, a transistor Ta of the transfer gate is conducted, and the monitoring element 11 is connected to the pad 4. As a result, the monitor element 11 can be measured through the pad 4 by the probing in an ordinary IC test.
|
