| 摘要 |
PURPOSE:To measure the large delay time of an IC tester by controlling a counter which counts a master clock when a mode waveform is inputted and when an output responding to the mode waveform is outputted. CONSTITUTION:The mode waveform is outputted from a pattern memory 1 by a pattern processor 2 and stored in a pattern output buffer 3. A pattern from this buffer 3 is inputted to an IC6 to be measured through a shaping circuit 4, etc., and inputted to a multiplexer 9 to which the master clock C is impressed, so that the counter 11 starts counting the clock C at the point of time when the mode waveform is inputted. The counter 11 is controlled through a multiplexer 10 impressed with a decision output from a comparing circuit 8 corresponding to the output of the IC6 and the expected value of the buffer 3 and this counting is carried on until the IC6 generates an output corresponding to the mode waveform. Then, the delay time of the IC tester which exceeds the capacity of a fail analyzing memory is measured by the counted value of the counter 11 with high precision. |
