Transparent enable test circuit

摘要

A test circuit for two level latches on an integrated circuit to be tested includes a test enable driver circuit coupled to a third level switch which is connected in series between the latches to be tested and a low voltage source. The third level switch converts the two level latches to be tested into a buffer such that data applied as an input to the two level latches appears in identical form as data at the output pin of the integrated circuit chip.