Automatic test system with enhanced performance of timing generators

Abstract

A unique automatic test system (100) is provided in which timing signals are generated in a novel manner as compared with prior art test systems. All adjustments for propagation delays of timing signals are made in a digital fashion, by adjusting the digital information which defines when an analog timing signal is to be generated. Deskewing of propagation delays is performed automatically under computer control, rather than by requiring careful adjustment of hardware deskewing elements. By adjusting for propagation skews digitally, propagation skews dependent on data values (logical 0 and logical 1) can be made. Furthermore, timing signals are provided by three timing edges, rather than by a timing pulse, thereby allowing more accurate generation of timing signals. The use of a complex switching matrix is eliminated by providing at least one timing generator per pin of the device under test, thereby eliminating complex hardware, propagation errors related to switching matrices, and providing enhanced capabilities for the user while simultaneously simplifying the problems associated with creating software used to control the test system during testing a device under test.