| 摘要 |
PURPOSE: To select one system among many systems that has to be tested by a defined number of control lines. CONSTITUTION: A plurality of systems 120 to 12n are controlled by a test value existing in a four-wire scan board 17, while they are tested. The test value therein is shifted in at least one buffer 16A which outputs a control signal to output lines S0 to S7 according to the value. The control signal from the buffer controls at least one multiplexer 18A and demultiplexer 18A and selects one system according to the control signal of the buffer. |
