学術リポジトリ naistar / NAIST Academic Repository naistar
http://hdl.handle.net/10061/1
2016-12-04T22:20:55ZEffective Launch-to-Capture Power Reduction for LOS Scheme with Adjacent-Probability-Based X-Filling
http://hdl.handle.net/10061/11176
Effective Launch-to-Capture Power Reduction for LOS Scheme with Adjacent-Probability-Based X-Filling
Miyase, Kohei; Uchinodan, Yuta; Enokimoto, Kazunari; Yamato, Yuta; Wen, Xiaoqing; Kajihara, Seiji; Wu, Fangmei; Luiji, Dilillo; Alberto, Bosio; Patrick, Girard; Arnaud, Virazel
It has become necessary to reduce power during LSI testing. Particularly, during at-speed testing, excessive power consumed during the Launch-To-Capture (LTC) cycle causes serious issues that may lead to the overkill of defect-free logic ICs. Many successful test generation approaches to reduce IR-drop and/or power supply noise during LTC for the launch-off capture (LOC) scheme have previously been proposed, and several of X-filling techniques have proven especially effective. With X-filling in the launch-off shift (LOS) scheme, however, adjacent-fill (which was originally proposed for shift-in power reduction) is used frequently. In this work, we propose a novel X-filling technique for the LOS scheme, called Adjacent-Probability-based X-Filling (AP-fill), which can reduce more LTC power than adjacent-fill. We incorporate AP-fill into a post-ATPG test modification flow consisting of test relaxation and X-filling in order to avoid the fault coverage loss and the test vector count inflation. Experimental results for larger ITC'99 circuits show that the proposed AP-fill technique can achieve a higher power reduction ratio than 0-fill, 1-fill, and adjacent-fill.
ATS : 2011 Asian Test Symposium , 20-23 Nov. 2011 , New Delhi, INDIA
2011-01-01T00:00:00ZSAT-based capture-power reduction for at-speed broadcast-scan-based test compression architectures
http://hdl.handle.net/10061/11178
SAT-based capture-power reduction for at-speed broadcast-scan-based test compression architectures
Michael A. Kochte; Miyase, Kohei; Wen, Xiaoqing; Kajihara, Seiji; Yamato, Yuta; Enokimoto, Kazunari; Wunderlich, Hans-Joachim
Excessive power dissipation during VLSI testing results in over-testing, yield loss and heat damage of the device. For low power devices with advanced power management features and more stringent power budgets, power-aware testing is even more mandatory. Effective and efficient test set postprocessing techniques based on X-identification and power-aware X-filling have been proposed for external and embedded deterministic test. This work proposes a novel X-filling algorithm for combinational and broadcast-scan-based test compression schemes which have great practical significance. The algorithm ensures compressibility of test cubes using a SAT-based check. Compared to methods based on topological justification, the solution space of the compressed test vector is not pruned early during the search. Thus, this method allows much more precise low-power X-filling of test vectors. Experiments on benchmark and industrial circuits show the applicability to capture-power reduction during scan testing.
ISLPED : 2011 International Symposium on Low Power Electronics and Design , 1-3 Aug 2011 , Fukuoka, Japan
2011-01-01T00:00:00ZPower-aware test generation with guaranteed launch safety for at-speed scan testing
http://hdl.handle.net/10061/11179
Power-aware test generation with guaranteed launch safety for at-speed scan testing
Wen, Xiaoqing; Enokimoto, Kazunari; Miyase, Kohei; Yamato, Yuta; Michael A. Kochte; Kajihara, Seiji; Girard, Patrick; Tehranipoor, Mohammad
At-speed scan testing may suffer from severe yield loss due to the launch safety problem, where test responses are invalidated by excessive launch switching activity (LSA) caused by test stimulus launching in the at-speed test cycle. However, previous low-power test generation techniques can only reduce LSA to some extent but cannot guarantee launch safety. This paper proposes a novel & practical power-aware test generation flow, featuring guaranteed launch safety. The basic idea is to enhance ATPG with a unique two-phase (rescue & mask) scheme by targeting at the real cause of the launch safety problem, i.e., the excessive LSA in the neighboring areas (namely impact areas) around long paths sensitized by a test vector. The rescue phase is to reduce excessive LSA in impact areas in a focused manner, and the mask phase is to exclude from use in fault detection the uncertain test response at the endpoint of any long sensitized path that still has excessive LSA in its impact area even after the rescue phase is executed. This scheme is the first of its kind for achieving guaranteed launch safety with minimal impact on test quality and test costs, which is the ultimate goal of power-aware at-speed scan test generation.
VTS : 2011 IEEE 29th VLSI Test Symposium , 1-5 May. 2011 , Dana Point, CA, USA
2011-01-01T00:00:00ZLoosely-Stabilizing Leader Election on Arbitrary Graphs in Population Protocols Without Identifiers nor Random Numbers
http://hdl.handle.net/10061/11180
Loosely-Stabilizing Leader Election on Arbitrary Graphs in Population Protocols Without Identifiers nor Random Numbers
Sudo, Yuichi; Ooshita, Fukuhito; Kakugawa, Hirotsugu; Masuzawa, Toshimitsu
In the population protocol model Angluin et al. proposed in 2004, there exists no self-stabilizing leader election protocol for complete graphs, arbitrary graphs, trees, lines, degree-bounded graphs and so on unless the protocol knows the exact number of nodes. To circumvent the impossibility, we introduced the concept of loose-stabilization in 2009, which relaxes the closure requirement of self-stabilization. A loosely-stabilizing protocol guarantees that starting from any initial configuration a system reaches a safe configuration, and after that, the system keeps its specification (e.g. the unique leader) not forever, but for a sufficiently long time (e.g. exponentially large time with respect to the number of nodes). Our previous works presented two loosely-stabilizing leader election protocols for arbitrary graphs; One uses agent identifiers and the other uses random numbers to elect a unique leader. In this paper, we present a loosely-stabilizing protocol that solves leader election on arbitrary graphs without agent identifiers nor random numbers. By the combination of virus-propagation and token-circulation, the proposed protocol achieves polynomial convergence time and exponential holding time without such external entities. Specifically, given upper bounds N and Delta of the number of nodes n and the maximum degree of nodes delta respectively, it reaches a safe configuration within O(m*n^3*d + m*N*Delta^2*log(N)) expected steps, and keeps the unique leader for Omega(N*e^N) expected steps where m is the number of edges and d is the diameter of the graph. To measure the time complexity of the protocol, we assume the uniformly random scheduler which is widely used in the field of the population protocols.
OPODIS 2015 : 19th International Conference on Principles of Distributed Systems, 14-17 Dec. 2015 , Rennes, France
2015-01-01T00:00:00Z