Patent ID: 7733113

Claim:
A semiconductor test device for conducting a test on a device under test, comprising: a plurality of comparison units which compare a signal obtained from the device under test with a predetermined reference voltage and output a comparison result; a plurality of measuring units which are provided in correspondence with the plurality of comparison units and measure a time from when a measurement start signal is input thereto to when the comparison result from a corresponding comparison unit is input thereto, and output a measuring result; a start signal output unit which outputs the measurement start signal at a same timing to each of the plurality of measuring units; and a computation unit which computes time differences between a plurality of signals obtained from the device under test based on the measuring results of the plurality of measuring units; a bus including at least one signal line; a switch unit which switches a connection between one of said plurality of comparison units and a signal line of the at least one signal line to an open state or a closed state; a first selecting unit which selects a signal line of the at least one signal line; and a gate unit which is provided between one of said plurality of comparison units and one of said plurality of measuring units, and controls an open/closed state in accordance with a signal which is transmitted via the signal line selected by the first selecting unit.