• Proceedings of the Korean Information Science Society Conference
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• 2003.10a
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• pp.265-267
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• 2003

내장형 컴퓨터 시스템은 특정 기능을 수행하기 위해 소프트웨어와 이를 구동시키기 위한 프로세서로 구성되어 있다. 이러한 시스템의 대부분은 실시간 제약들을 만족해야 한다. 실시간 제약들을 만족하는 애플리케이션을 빠른 시간안에 구현하기 위해서는 제작 전 성능을 예측하는 도구가 필수적이다. 본 논문에서는 현재 내장형 시스템 플랫폼으로 널리 활용되고 있는 ARM 기반의 내장형 애플리케이션의 극단적인(최적, 최악) 경우의 수행 시간 경계를 예측하는 문제를 연구하였다. ARM 기반의 내장형 시스템의 수행시간의 경계를 예측하기 위하여 기존의 실시간 내장형 소프트웨어의 성능 예측 도구인“Cinderella”의 기본 프레임웍을 ARM 프로세서를 지원하도록 확장하여 성능분석도구를 설계하였다.

• Journal of KIISE:Computing Practices and Letters
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• v.11 no.1
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• pp.15-25
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• 2005

Embedded systems have a set of tasks to execute. These tasks can be implemented either on application specific hardware or as software running on a specific processor. The design of an embedded system involves the selection of hardware software resources, Partition of tasks into hardware and software, and performance evaluation. An accurate estimation of execution time for extreme cases (best and worst case) is important for hardware/software codesign. A tighter estimation of the execution time bound nay allow the use of a slower processor to execute the code and may help lower the system cost. In this paper, we consider an ARM-based embedded system and developed a tool to estimate the tight boundary of execution time of a task with loop bounds and any additional program path information. The tool we developed is based on an exiting timing analysis tool named 'Cinderella' which currently supports i960 and m68k architectures. We add a module to handle ARM ELF object file, which extracts control flow and debugging information, and a module to handle ARM instruction set so that the new tool can support ARM processor. We validate the tool by comparing the estimated bound of execution time with the run-time execution time measured by ARMulator for a selected bechmark programs.

• The KIPS Transactions:PartA
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• v.9A no.4
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• pp.441-450
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• 2002

As the size of embedded system software increase bigger and bigger, and it's complexity is grower and grower, the usage of dynamic memory management scheme such collector also has been increased. Using the garbage collector, however, inherently lead us performance degradation. In order to resolve this kind of performance problem in the Java based embedded system. we introduce an explicit dynamic memory free method to the automated dynamic memory management environment. which can be performed by a programmer. In the worst case, the prosed scheme shows the same performance as the case of that only garbage collector is working, since the unclaimed garbage objects will eventually be collected later by the garbage collector. In the best case. our method is free from any runtime overhead because the applications can be implemented without any intervention of the garbage collector. Although the proposed method can be facilitated with all the existing garbage collection algorithms, it shows an outperform in the case of mark-and-sweep algorithm.