Title :
X-routing using two Manhattan route instances
Author :
Ahmad, Seraj ; Jayakumar, Nikhil ; Balasubramanian, Vijay ; Hursey, Edward ; Khatri, Sunil P. ; Mahapatra, Rabi
Author_Institution :
Dept. of CS, Texas A&M Univ., College Station, TX, USA
Abstract :
In deep sub-micron (DSM) technologies, wire delays comprise a dominant fraction of the total delay of a design. As a consequence, routing techniques which reduce the total wire length of a design are highly relevant to such technologies. One such approach which holds promise is that of non-Manhattan routing (or X routing). In this paper, we describe a technique to perform non-Manhattan routing by combining the results of two related Manhattan routing instances. The first is a regular, unrotated routing instance. The second routing instance is derived from the first by rotating the coordinate system by 45°. Both instances are routed on the same pair of metal layers. By selectively combining the results of the two instances, we obtain a final routing result that contains non-Manhattan wire segments. Our approach utilizes a powerful Floyd-Warshall based engine to combine the results of the two instances. We demonstrate that our router produces highly efficient results, reducing the total wire length by an average of about 20% (31%) over the unrotated (rotated) results, with a via-count decrease of between 4% (43%).
Keywords :
VLSI; integrated circuit design; integrated circuit interconnections; logic design; network routing; Floyd-Warshall based engine; Manhattan route instance; X-routing; deep sub-micron technology; metal layer; nonManhattan routing; nonManhattan wire segment; regular routing instance; total wire length; unrotated routing instance; wire delay; Clocks; Counting circuits; Delay systems; Distributed decision making; Engines; Pins; Routing; Wire; Wiring;
Conference_Titel :
Computer Design: VLSI in Computers and Processors, 2005. ICCD 2005. Proceedings. 2005 IEEE International Conference on
Print_ISBN :
0-7695-2451-6
DOI :
10.1109/ICCD.2005.117
