FREe: A Fast Routability Estimator

A fast routability estimator, namely FREe, is proposed in this paper. With the fast feedback on congestion, FREe serves incremental placement or guides routing to shorten the physical design time. FREe firstly extends an existing combinatorial model with the extended bounding box for flat tow-pin nets/sections to pre-estimate congestion probabilistically. Then, it routes all nets guided by the pre-estimation to get more exact congestion estimation, which is fast since it does not include any iteration/optimization as a router does. The idea of FREe is net-order-independent. FREe can get a uniform usage of routing resources by probability. The experimental results show that FREe can give more detailed congestion information in a short running time. Compared FREe with a recent router SSTT, we find that FREe has a good congestion correlation with SSTT, but FREe is more objective

[1]  Ulrich Lauther,et al.  Congestion-driven placement using a new multi-partitioning heuristic , 1990, 1990 IEEE International Conference on Computer-Aided Design. Digest of Technical Papers.

[2]  F. Hwang,et al.  An o(nlogn) algorithm for suboptimal rectilinear steiner trees , 1979 .

[3]  Patrick Groeneveld,et al.  Probabilistic congestion prediction , 2004, ISPD '04.

[4]  胡晓东,et al.  ACO-Steiner： Ant Colony Optimization Based Rectilinear Steiner Minimal Tree Algorithm , 2006 .

[5]  Shankar Krishnamoorthy,et al.  Estimating routing congestion using probabilistic analysis , 2002, IEEE Trans. Comput. Aided Des. Integr. Circuits Syst..

[6]  Majid Sarrafzadeh,et al.  Modeling and minimization of routing congestion , 2000, Proceedings 2000. Design Automation Conference. (IEEE Cat. No.00CH37106).

[7]  Georg Sigl,et al.  GORDIAN: VLSI placement by quadratic programming and slicing optimization , 1991, IEEE Trans. Comput. Aided Des. Integr. Circuits Syst..

[8]  Majid Sarrafzadeh,et al.  On the behavior of congestion minimization during placement , 1999, ISPD '99.

[9]  David S. Johnson,et al.  The Rectilinear Steiner Problem is NP-Complete , 1977 .

[10]  Andrew B. Kahng,et al.  Toward accurate models of achievable routing , 2001, IEEE Trans. Comput. Aided Des. Integr. Circuits Syst..

[11]  Richard B. Brown,et al.  Congestion driven quadratic placement , 1998, Proceedings 1998 Design and Automation Conference. 35th DAC. (Cat. No.98CH36175).

[12]  Chih-Liang Eric Cheng.  RISA: accurate and efficient placement routability modeling , 1994, ICCAD.

[13]  Jun Gu,et al.  SSTT: Efficient local search for GSI global routing , 2003, Journal of Computer Science and Technology.

[14]  Ulrich Brenner,et al.  An effective congestion driven placement framework , 2002, ISPD '02.

[15]  Frank K. Hwang,et al.  An O(n log n) Algorithm for Rectilinear Minimal Spanning Trees , 1979, JACM.

[16]  Raia Hadsell,et al.  Improved global routing through congestion estimation , 2003, Proceedings 2003. Design Automation Conference (IEEE Cat. No.03CH37451).

[17]  Ren-Song Tsay,et al.  Early wirability checking and 2D congestion-driven circuit placement , 1992, [1992] Proceedings. Fifth Annual IEEE International ASIC Conference and Exhibit.

[18]  Jason Cong,et al.  Incremental CAD , 2000, IEEE/ACM International Conference on Computer Aided Design. ICCAD - 2000. IEEE/ACM Digest of Technical Papers (Cat. No.00CH37140).

[19]  Jinjun Xiong,et al.  Probabilistic congestion model considering shielding for crosstalk reduction , 2005, ASP-DAC.