adapter ATE can be used on packaged parts (typical IC 'chip') or directly on the silicon wafer. Packaged parts use a handler to place the device on a customized interface board, whereas silicon wafers are tested directly with high precision probes. The ATE systems interact with the handler or prober to test the DUT. Packaged part ATE with handlers ATE systems typically interface with an automated placement tool, called a "handler", that physically places the Device Under Test (DUT) on an Interface Test Adapter (ITA) so that it can be measured by the equipment. There may also be an Interface Test Adapter (ITA), a device just making electronic connections between the ATE and the Device Under Test (also called Unit Under Test or UUT), but also it might contain an additional circuitry to adapt signals between the ATE and the DUT and has physical facilities to mount the DUT. Finally, a socket is used to bridge the connection between the ITA and the DUT. A socket must survive the rigorous demands of a production floor, so they are usually replaced frequently. Simple electrical interface diagram: ATE → ITA → DUT (package) ← Handler Silicon wafer ATE with probers Wafer-based ATEs typically use a device called a prober that moves across a silicon wafer to test the device. Simple electrical interface diagram: ATE → Prober → Wafer (DUT) Multi-site One way to improve test time is to test multiple devices at once. ATE systems can now support having multiple "sites" where the ATE resources are shared by each site. Some resources can be used in parallel, others must be serialized to each DUT. Programming ATE The ATE computer uses modern computer languages (like C, C++, Java, Python, LabVIEW or Smalltalk) with additional statements to control the ATE equipment through standard and proprietary application programming interfaces (API). Also some dedicated computer languages exist, like Abbreviated Test Language for All Systems (ATLAS). Automatic test equipment can also be automated using a test execution engine such as NI's TestStand. Sometimes automatic test pattern generation is used to help design the series of tests. Test data (STDF) Many ATE platforms used in the semiconductor industry output data using Standard Test Data Format (STDF) Diagnostics Automatic test equipment diagnostics is the part of an ATE test that determines the faulty components. ATE tests perform two basic functions. The first is to test whether or not the