| 摘要 |
PURPOSE:To curtail testing time without necessity of scanning out operation by utilizing non-contact measuring means using electron beams. CONSTITUTION:For testing an integrated circuit providing a test facilitating circuit by the scanning system, after a test pattern is input to a shift register as the test mode, a potential of the input or output terminal of flip-flop is read on the non-contact basis without the scanning out operation. First, after the test flip-flops 1 are all reset, signal ''1'' is given to the test pattern input terminal and the clock is added four times, Next, electron beam is applied to the output terminals QA-QD of the flip-flops 1 in order to detect the status. When QA=1, QB=1. QC=1, QD=1, the flip-flops 1 and the switch circuit 2 are normal. The combined circuit 3 can also be tested by reading a potential at the D input terminals DA-DD of the flip-flops 1 with the electron beams by changing again the operation mode to the normal operation. |
