This archive contains a collection of reports generated by the faculty and students of the Institute for Systems Research (ISR), a permanent, interdisciplinary research unit in the A. James Clark School of Engineering at the University of Maryland. ISR-based projects are conducted through partnerships with industry and government, bringing together faculty and students from multiple academic departments and colleges across the university.
Browsing Institute for Systems Research Technical Reports by Subject "3D-IC"
The three dimensional circuit (3D-IC) brings forth new challenges to physical design such as allocation and management of through-silicon-vias (TSVs). Meanwhile, the thermal issues in 3D-IC becomes significant necessitating the use of active cooling schemes such as micro-channel liquid coolings. Both TSVs and micro-channels
go through the interlayer regions of 3D-IC resulting in potential resource conflict, which deters the optimization of both
micro-channel design and TSV allocation/management. This paper
investigates the co-optimization of TSV assignment to interlayer nets and micro-channel allocation such that both wirelength and micro-channel cooling energy are co-optimized. We propose a multi-commodity flow based formulation followed by simplifying
transformations that enable use of effective polynomial time heuristics. The experimental results show that, our co-optimization
approach achieves 46% cooling power savings or 7.6% wire length reduction compared with the approaches that assign TSVs and allocate micro-channels separately.
The performance improvement of modern computer systems is usually accompanied by increased computational power and thermal hotspots, which in turn limit the further
improvement of system performance. In 3D-ICs, this thermal problem is significantly exacerbated, necessitating the need for active cooling approaches such as micro-fluidic cooling. This paper investigates a co-optimization approach for 3D-IC electric (gate sizing) and cooling design that fully exploits the interdependency between power, temperature and circuit delay to push the powerperformance tradeoff beyond conventional limits. We propose a unified formulation to model this co-optimization problem and use an iterative optimization approach to solve the problem. The experimental results show a fundamental power-performance improvement, with 12% power saving and 16% circuit speedup.
Micro-channel based liquid cooling has significant capability of removing high density heat in 3D-ICs. The conventional micro-channel structures investigated for cooling 3D-ICs use straight channels. However, the presence of TSVs which form obstacles to the micro-channels prevents distribution of straight micro-channels. In this paper, we investigate the methodology of designing TSV-constrained micro-channel infrastructure. Specifically, we
decide the locations and geometry of micro-channels with bended structure so that it's cooling e®ectiveness is maximized. Our micro-channel structure could achieve up to 87% pumping power saving compared with the micro-channel structure using straight channels.