Test device and test method

摘要

A testing apparatus according to the present invention includes: a clock generating circuit for generating a reproduced clock of which frequency and phase are substantially the same as frequency of the reference clock and phase of output data of a device under test, respectively; a delay circuit for generating a strobe for delaying the reproduced clock; a timing comparator for obtaining an output value of the output data based on the strobe; a logic comparing unit for comparing the output value with a predetermined expectation value; and a pass/fail determining module for determining pass/ fail of the device under test based on the comparison result of the logic comparing unit, and the clock generating circuit includes: a first phase comparing unit for comparing phase of the output data of the device under test with that of the reproduced clock and outputting a first comparison result signal; a second phase comparing unit for comparing phase of the reference clock with that of the reproduced clock and outputting a second comparison result signal; and a reproduced clock generating module for generating the reproduced clock based on the first and second comparison result signals.