Patent ID: 7126366
Filing Date: 2006-10-24
Classification: G01R

Abstract:
1. A semiconductor test apparatus, comprising: differential signal timing measurement means for outputting cross point information obtained by measuring a timing of a cross point of differential signals from a device under test (DUT); non-differential signal timing measurement means for outputting data change point information obtained by measuring a timing of transition of logic of a data signal from the DUT; phase difference calculation means for outputting a phase difference obtained by calculating a relative phase difference between the cross point information and the data change point information; and PASS/FAIL determination means for determining PASS/FAIL of the phase difference of the DUT with respect to a predetermined range based on predetermined upper and lower limit threshold values or one of the threshold values; wherein the differential signal timing measurement means comprises first transition information measurement means for converting the differential signals into logical signals at predetermined threshold levels for measuring two points before and after the cross point with respect to a transition waveform of one of the output differential signals, sampling and measuring the logical signals based on a multiphase strobe signal, then converting the logical signals into code data, and outputting the code data as timing information, second transition information measurement means for converting the differential signals into logical signals at predetermined threshold levels for measuring two points before and after the cross point with respect to a transition waveform of the other of the output differential signals, sampling and measuring the signals based on a multiphase strobe signal, then converting the signals into code data, and outputting the code data as timing information, and cross point calculation means for specifying a position of intersection of both straight lines as the cross point information, the straight lines being obtained by the code data from the first and second transition information measurement means; and wherein the non-differential signal timing measurement means comprises data transition time information collection means for receiving the data signal from the DUT, converting the data signal into a logical signal at a predetermined threshold level, sampling and measuring the logical signal based on a multiphase strobe signal, converting the logical signal into code data indicating timing information of one of rising and falling of the data signal, and then outputting code data as data change point information.