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Full-Text Articles in Physical Sciences and Mathematics
Minimizing Channel Density With Movable Terminals, Ronald I. Greenberg, Jau-Der Shih
Minimizing Channel Density With Movable Terminals, Ronald I. Greenberg, Jau-Der Shih
Computer Science: Faculty Publications and Other Works
We give algorithms to minimize density for VLSI channel routing problems with terminals that are movable subject to certain constraints. The main cases considered are channels with linear order constraints, channels with linear order constraints and separation constraints, channels with movable modules containing fixed terminals, and channels with movable modules and terminals. In each case, we improve previous results for running time and space by a factor of L/\lgn and L, respectively, where L is the channel length, and n is the number of terminals.
Parallel Algorithms For Single-Layer Channel Routing, Ronald I. Greenberg, Shih-Chuan Hung, Jau-Der Shih
Parallel Algorithms For Single-Layer Channel Routing, Ronald I. Greenberg, Shih-Chuan Hung, Jau-Der Shih
Computer Science: Faculty Publications and Other Works
We provide efficient parallel algorithms for the minimum separation, offset range, and optimal offset problems for single-layer channel routing. We consider all the variations of these problems that are known to have linear- time sequential solutions rather than limiting attention to the "river-routing" context, where single-sided connections are disallowed. For the minimum separation problem, we obtain O(lgN) time on a CREW PRAM or O(lgN / lglgN) time on a (common) CRCW PRAM, both with optimal work (processor- time product) of O(N), where N is the number of terminals. For the offset range problem, we obtain the same time and processor …
Feasible Offset And Optimal Offset For General Single-Layer Channel Routing, Ronald I. Greenberg, Jau-Der Shih
Feasible Offset And Optimal Offset For General Single-Layer Channel Routing, Ronald I. Greenberg, Jau-Der Shih
Computer Science: Faculty Publications and Other Works
This paper provides an efficient method to find all feasible offsets for a given separation in a very large-scale integration (VLSI) channel-routing problem in one layer. The previous literature considers this task only for problems with no single-sided nets. When single-sided nets are included, the worst-case solution time increases from $\Theta ( n )$ to $\Omega ( n^2 )$, where n is the number of nets. But if the number of columns c is $O( n )$, the problem can be solved in time $O( n^{1.5} \lg n )$, which improves upon a “naive” $O( cn )$ approach. As a …
Minimum Separation For Single-Layer Channel Routing, Ronald I. Greenberg, F. Miller Maley
Minimum Separation For Single-Layer Channel Routing, Ronald I. Greenberg, F. Miller Maley
Computer Science: Faculty Publications and Other Works
We present a linear-time algorithm for determining the minimum height of a single-layer routing channel. The algorithm handles single-sided connections and multiterminal nets. It yields a simple routability test for single-layer switchboxes, correcting an error in the literature.