Testing delay-insensitive circuits

Author: Hazewindus, Pieter Johannes

Year: 1992

Degree: Dissertation (Ph.D.)

Advisor: Martin, Alain J.

Committee Members: Martin, Alain J.; Seitz, Charles L.; Van de Snepscheut, Jan L. A.; Abu-Mostafa, Yaser S.

Option: Computer Science

DOI: 10.7907/0d7v-9d09

Abstract

A method is developed to test delay-insensitive circuits, using the single stuck-at fault model. These circuits are synthesized from a high-level specification. Since the circuits are hazard-free by construction, there is no test for hazards in the circuit. Most faults cause the circuit to halt during test, since they cause an acknowledgement not to occur when it should. There are stuck-at faults that do not cause the circuit to halt under any condition. These are stimulating faults; they cause a premature firing of a production rule. For such a stimulating fault to be testable, the premature firing has to be propagated to a primary output. If this is not guaranteed to occur, then one or more test points have to be added to the circuit. Any stuck-at fault is testable, with the possible addition of test points. For combinational delay-insensitive circuits, finding test vectors is reduced to the same problem as for synchronous combinational logic. For sequential circuits, the synthesis method is used to find a test for each fault efficiently, to find the location of the test points, and to find a test that detects all faults in a circuit.

The number of test points needed to fully test the circuit is very low, and the size of the additional testing circuitry is small. A test derived with a simple transformation of the handshaking expansion yields high fault coverage. Adding tests for the remaining faults results in a small complete test for the circuit.

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