• 대한전자공학회논문지SD
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• 제43권1호
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• pp.71-78
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• 2006

NoC 테스트는 온칩네트워크를 TAM으로 재사용하기 때문에 SoC 구조 기반의 여러 테스트 기법을 그대로 사용할 수가 없다. 본 논문에서는 네트워크 기반 TAM의 문제점을 크게 감소시킨 새로운 형태의 NoC 테스트 플랫폼을 소개하며 이를 이용한 NoC 테스트 스케줄링 알고리즘을 제안한다. 제안한 알고리즘은 SoC 테스트 용도로 개발된 rectangle packing 방식을 기반으로 효율적이고 체계적인 테스트 스케줄링이 가능하게 한다. ITC'02 벤치회로를 이용한 실험 결과 제안한 방법이 기존 방법에 비해 최대 $55\%$까지 테스트 시간을 줄일 수 있음을 확인하였다.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2003년도 가을 학술발표논문집 Vol.30 No.2 (1)
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• pp.208-210
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• 2003

본 논문은 SOC 내에 존재하는 코아들을 테스트하는 과정에서 개별 코아들의 테스트 조건을 기반으로 한 스케듈링을 통해 최적의 Test ing time을 구하는 연구이다. SOC 내에 존재하는 코아들은 주어지는 TAM(Test Access Mechanism) Width에 따라 각코아들의 Width가 달라지고, 최대 Width에서 최소 Width(1)까지 각 Width 별로 Testing time을 계산할 수 있다. 코아들의 각 Width 별 Testing time을 기존의 Rectangle Packing Algorithm을 수정, 보완하여 효율적으로 구성한 수정 Rectangle Packing Algorithm에 적응하여 최적의 Testing time을 구하는 것이 본 논문의 목적이다.

• ETRI Journal
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• 제28권4호
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• pp.475-485
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• 2006

Network-on-chip (NoC) is an emerging design paradigm intended to cope with future systems-on-chips (SoCs) containing numerous built-in cores. Since NoCs have some outstanding features regarding design complexity, timing, scalability, power dissipation and so on, widespread interest in this novel paradigm is likely to grow. The test strategy is a significant factor in the practicality and feasibility of NoC-based SoCs. Among the existing test issues for NoC-based SoCs, test access mechanism architecture and test scheduling particularly dominate the overall test performance. In this paper, we propose an efficient NoC-based SoC test scheduling algorithm based on a rectangle packing approach used for current SoC tests. In order to adopt the rectangle packing solution, we designed specific methods and configurations for testing NoC-based SoCs, such as test packet routing, test pattern generation, and absorption. Furthermore, we extended and improved the proposed algorithm using multiple test clocks. Experimental results using some ITC'02 benchmark circuits show that the proposed algorithm can reduce the overall test time by up to 55%, and 20% on average compared with previous works. In addition, the computation time of the algorithm is less than one second in most cases. Consequently, we expect the proposed scheduling algorithm to be a promising and competitive method for testing NoC-based SoCs.

• 대한전자공학회논문지SD
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• 제45권2호
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• pp.93-100
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• 2008

본 논문에서는 NoC 기반 SoC의 테스트 시간을 감소시키기 위하여 NoC를 TAM으로 재활용하는 구조를 바탕으로 하는 새로운 형태의 스케줄링 알고리즘을 제안한다. 제안한 방식에서는 기존 연구된 NoC 테스트 플랫폼을 사용하여 스케줄링 문제를 rectangle packing 문제로 변환하고 이를 simulated annealing(SA) 기법을 적용하여 향상된 스케줄링 결과를 유도한다. ITC'02 벤치회로를 이용한 실험 결과 제안한 방법이 기존 방법에 비해 최대 2.8%까지 테스트 시간을 줄일 수 있음을 확인하였다.

• ETRI Journal
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• 제30권1호
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• pp.129-140
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• 2008

In this paper, we propose a novel ant colony optimization (ACO)-based test scheduling method for testing network-on-chip (NoC)-based systems-on-chip (SoCs), on the assumption that the test platform, including specific methods and configurations such as test packet routing, generation, and absorption, is installed. The ACO metaheuristic model, inspired by the ant's foraging behavior, can autonomously find better results by exploring more solution space. The proposed method efficiently combines the rectangle packing method with ACO and improves the scheduling results by dynamically choosing the test-access-mechanism widths for cores and changing the testing orders. The power dissipation and variable test clock mode are also considered. Experimental results using ITC'02 benchmark circuits show that the proposed algorithm can efficiently reduce overall test time. Moreover, the computation time of the algorithm is less than a few seconds in most cases.

• 대한산업공학회지
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• 제27권4호
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• pp.424-431
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• 2001

This paper is concerned with the unconstrained two-dimensional cutting problem of cutting small rectangles (products), each of which has its own profit and size, from a large rectangle (material) to maximize the profit-sum of products. Since this problem is used as a sub-problem to generate a cutting pattern in the algorithms for the two-dimensional cutting stock problem, most of researches for the two-dimensional cutting stock problem have been concentrated on solving this sub-problem more efficiently. This paper improves Hifi and Zissimopoulos's recursive algorithm, which is known as the most efficient exact algorithm, by applying newly proposed upper bound and searching strategy. The experimental results show that the proposed algorithm has been improved significantly in the computational amount of time as compared with the Hifi and Zissimopulos's algorithm.