TEST INSTRUMENT AND TEST METHOD

摘要

A test instrument for testing a device under test comprises a level comparing section for receiving a test subject signal outputted from the device under test and outputting logical values indicating the results of the comparison of the level of the test subject signal with predetermined first and second thresholds, an acquiring section for acquiring the logical value outputted from the level comparing section in response to a fed strobe signal, an expectation value comparing section for judging whether or not the acquired logical value agrees with a predetermined expectation value, and a threshold control section for setting the upper and lower limit values of the voltage of a predetermined eye mask as the first and second thresholds in the level comparing section when an eye mask test to judge whether or not the eye aperture of the test subject signal is larger than the eye mask.