Testing redundant asynchronous circuits by variable phase splitting
Luciano Lavagno, Antonio Lioy, Michael Kishinevsky · 1994
An approach for stuck-at-i and delay-fault testing of redundant circuits without modifying the logic is proposed. The only requirement is the ability to control both phases of each variable independent of each other. The circuit becomes fully testable under very weak assumptions, equivalent to freedom from Single Cube Containment in two-level form. The main existing methods for asynchronous circuit synthesis are demonstrated to satisfy the assumptions and then are testable using the methodology. Heuristics to improve the approach include partial scan and non-scan testing. 1 Introduction A practical application of asynchronous circuits until now has been almost entirely limited to "niches" such as asynchronous buses. This is certainly due to the difficulty of introducing a completely new design methodology. Automated design aids can help in this respect, but another major obstacle remained until now. No digital circuit design methodology can be used in practice unless it also provides...