ATE digital testing using a programmable microsequencer architecture

In the past, the digital testing of an aircraft's complex line replaceable units (LRUs) on large automatic test equipment (ATE) was handled by designing a special set of interface boards. As more and different LRUs were added to the aircraft, the test stations began to run out of room in the interface test adapter (ITA) patch panel. The solution was to design an interface board that uses a microcoded bit-slice architecture. This allowed many parallel and serial test requirements to be met with only a new microprogram, thereby eliminating the need to design a new interface board when new requirements were added to the test station. It also allowed making changes easier. Putting multiple copies of a design into a test station allowed it to meet different requirements simultaneously. This microprogrammable architecture has been designed into the various ATE at the General Dynamics Electronics Division. These digital interface boards support over 300 different microprograms on over 50 LRUs on four different aircraft (F-16, B-1B, C-17, and C-5).