Patent ID: 7631234

Claim:
A test apparatus for testing a device under test, comprising: a test pattern generating section that generates a test pattern to test the device under test every test period; a plurality of edge generators that respectively generate an edge of a test signal to be supplied to the device under test based on the test pattern every cycle period of a reference clock that is used as a reference for an operation of this test apparatus; a selecting section that selects which edge generator generates each edge of a test signal to be output during the next cycle period based on a pattern of the edge generated during the current cycle period; and a test signal supplying section that supplies the test signal according to each edge generated from the selected edge generator to the device under test, wherein the selecting section comprises: a storing section that stores the edge generator for finally generating an edge during the current cycle period; and an interleaving section that selects the edge generator different from the edge generator stored on the storing section so that the different edge generator generates an initial edge during the next cycle period.