A unified approach for the synthesis of self-testable finite state machines

Abstract

Conventionally self-test hardware is added after synthesis is completed. For highly sequential circuits like controllers this design method either leads to high hardware overheads or compromises fault coverage. In this paper we outline a unified approach for considering self-test hardware like pattern generators and signature registers during synthesis. Three novel target structures are presented, and a method for designing parallel self-testable circuits is discussed in more detail. For a collection of benchmark circuits we show that hardware overheads for self-testable circuits can be significantly reduced this way without sacrificing testability.