Date: Thursday 12 March 2015
Time: 16:00 - 17:30
Location / Room: Stendhal
Chair:
Dirk Stroobandt, Ghent University, BE
Co-Chair:
Patrick Groeneveld, Synopsys, US
Place-and-route remain at the core of physical design, but must address a variety of important objectives, constraints and concerns. They can be added by standard-cell design to improve routing congestion while keeping area small.
| Time | Label | Presentation Title Authors |
|---|---|---|
| 16:00 | 12.3.1 | AN EFFECTIVE TRIPLE PATTERNING AWARE GRID-BASED DETAILED ROUTING APPROACH Speakers: Zhiqing Liu, Chuangwen Liu and Evangeline Young, The Chinese University of Hong Kong, HK Abstract Triple patterning lithography (TPL) is attracting more and more attention due to further scaling of the critical feature size. How fully the benefits of TPL can be utilized depends very much on both the decomposition and layout steps. However, it is non-trivial to perform detailed routing and layout decomposition simultaneously on a large-scale complicated circuit to achieve decomposability on one hand, and short wirelength, small number of stitches and small number of vias at the same time. Instead, in our approach, routing and coloring are done iteratively but integrated closely to reduce the problem complexity. The routing step is able to detect and avoid native conflicts as much as possible. If any conflicts occur in the coloring step, the router will rip-up and re-route to get rid of them. This technique proves to be effective and efficient in improving the quality of the coloring assignment. Compared with previous works~cite{dac12-ma} on TPL using the simultaneous routing and coloring method, the number of stitches and the number of vias are reduced by 76.8% and 2.1% respectively while our running time is 36.6% less and the wirelength is very comparable. Download Paper (PDF; Only available from the DATE venue WiFi) |
| 16:30 | 12.3.2 | SIMULTANEOUS TRANSISTOR PAIRING AND PLACEMENT FOR CMOS STANDARD CELLS Speakers: Ang Lu, Hsueh-Ju Lu, En-Jang Jang, Yu-Po Lin, Chun-Hsiang Hung, Chun-Chih Chuang and Rung-Bin Lin, Yuan Ze University, TW Abstract This paper presents an integer linear programming approach to transistor placement problem for CMOS standard cells with objectives of minimizing cell width, wiring density, wiring length, diffusion contour roughness, and misalignments of common ploy gates. Our approach considers transistor pairing and transistor placement simultaneously. It can achieve a smaller number of transistor chains than the well-known bipartite approach. About 31% of the 185 cells created by it have smaller widths and no cells whose widths are larger than their handcrafted counterparts. Download Paper (PDF; Only available from the DATE venue WiFi) |
| 17:00 | 12.3.3 | A TSV NOISE-AWARE 3-D PLACER Speakers: Yu-min Lee, Chun Chen, Jia-xing Song and Kuan-te Pan, National Chiao Tung University, TW Abstract In this work, a three-dimensional partitioning-based force-directed placer is developed to minimize coupling noise between through silicon vias (TSVs) in three-dimensional integrated circuits. TSV decoupling force is introduced and determined by the TSV coupling noise to separate TSVs with strong coupling noise. The experimental results indicate that TSV coupling noise can be effectively reduced by 36.3% on average with only 6.0% wirelength overhead. Besides, the developed 3-D placer shows great performance in wirelength that is competitive to a state-of-the-art 3-D placer. Download Paper (PDF; Only available from the DATE venue WiFi) |
| 17:15 | 12.3.4 | IDENTIFYING REDUNDANT INTER-CELL MARGINS AND ITS APPLICATION TO REDUCING ROUTING CONGESTION Speakers: Woohyun Chung, Seongbo Shim and Youngsoo Shin, Korea Advanced Institute of Science and Technology, KR Abstract A modern standard cell is embedded with extra space, called inter-cell margin, on its left and right ends. Margins are sometimes redundant, and so margins between some cell pairs can be removed for the benefit of area. Lithography simulations on whole layout to identify redundant margins take excessive amount of time, and thus are impractical. We propose to determine in advance the redundancy of margins between each cell pair; a few methods of approximation are introduced to accelerate the process, e.g. grouping cell pairs of similar boundary patterns, refining each group with geometry parameters, etc. Experiments indicate that the redundancy of margin is accurately determined in 93.7% of cell pairs; the remaining 6.3%, which are actually redundant, are declared irredundant by our method, so our method is inaccurate for those cell pairs yet is still safe. We take advantage of redundant margins and address the problem of routing congestion reduction. Placement is locally perturbed to identify more redundant margins; the cells in high congestion region are spread out after the margins in low congestion area are removed. The proposed method was evaluated on a few test circuits using 28-nm technology. The number of routing grids with congestion overflow was reduced by 43% with no impact on total wirelength. Download Paper (PDF; Only available from the DATE venue WiFi) |
| 17:30 | End of session | |