Title
Accurate Multi-cycle ATPG in Presence of X-Values
Abstract
Unknown (X) values in a circuit impair test quality and increase test costs. Classical n-valued algorithms for fault simulation and ATPG, which typically use a three- or four-valued logic for the good and faulty circuit, are in principle pessimistic in presence of X-values and cannot accurately compute the achievable fault coverage. In partial scan or pipelined circuits, X-values originate in non-scan flip-flops. These circuits are tested using multi-cycle tests. Here we present multi-cycle test generation techniques for circuits with X-values due to partial scan or other X-sources. The proposed techniques have been integrated into a multi-cycle ATPG framework which employs formal Boolean and quantified Boolean (QBF) satisfiability techniques to compute the possible signal states in the circuit accurately. Efficient encoding of the problem instance ensures reasonable runtimes. We show that in presence of X-values, the detection of stuck-at faults requires not only exact formal reasoning in a single cycle, but especially the consideration of multiple cycles for excitation of the fault site as well as propagation and controlled reconvergence of fault effects. For the first time, accurate deterministic ATPG for multi-cycle test application is supported for stuck-at faults. Experiments on ISCAS'89 and industrial circuits with X-sources show that this new approach increases the fault coverage considerably.
Year
DOI
Venue
2013
10.1109/ATS.2013.53
Asian Test Symposium
Keywords
Field
DocType
achievable fault coverage,multi-cycle test application,fault site,fault effect,stuck-at fault,multi-cycle atpg framework,multi-cycle test,fault simulation,increase test cost,accurate multi-cycle atpg,fault coverage,automatic test pattern generation,boolean functions,computability,atpg
Stuck-at fault,Boolean function,Automatic test pattern generation,Fault coverage,Computer science,Satisfiability,Algorithm,Real-time computing,Computability,Boolean algebra,Electronic circuit
Conference
ISSN
Citations 
PageRank 
1081-7735
9
0.58
References 
Authors
12
5
Name
Order
Citations
PageRank
Dominik Erb1334.45
Michael A. Kochte227627.23
Matthias Sauer319520.02
Hans-Joachim Wunderlich41822155.30
B. Becker519121.44