Test functional diagnosing of digital units with memory

A method is discussed of test functional diagnosing of digital units with memory, DUM, which are designed by the through shift register method [1]. A ring register may be used for testing and the functioning checked by an in-built digital unity, IDU. The method restores the pre-test internal test for continueing the functioning and repertition after faults that are detected by IDUs. A case study is provided of test functional DUM diagnosing.