The design of a scalable optical local area network formultiprocessing systems is described. Each workstation has aparallel-fiber-ribbon optical link to a centralized complementarymetal-oxide silicon (CMOS) switch core, implemented on a singlecompact printed circuit board (PCB). When the Motorola Optobusfiber technology is used, each workstation has a data bandwidth of 6.4Gbits/s to the core. A centralized switch core interconnecting 32workstations supports a 204-Gbit/s aggregate data bandwidth. Theswitch core is based on a conventional broadcast-and-selectarchitecture, implemented with parallel CMOS integrated circuits(IC's). The switch core scales well; by incorporation of theCMOS optoelectronic IC's with optical input-output, the electricalcore can be reduced to a single-chip optoelectronic IC with terabitcapacities. A prototype of an optoelectronic switch core has been fabricated and is described. The appeal of the architectureincludes its reliance on commercially available parallel-fibertechnology, its reliance on the well-developed markets of local areanetworks and networks of workstations, and its smooth scalability from the electrical to optical domains as technology matures.

No abstract

No abstract

it is shüwn that 1al'ger' circuits require 50%-60'K 1es::; wire1engthvhen utilising the thircl dimensiou,

Three dimensional integration is an increasingly feasible method of implementing complex circuitry. For large circuits, which most benefit from 3-D designs, efficient placement algorithms with low time complexity are required.We present an iterative 3-D placement algorithm that places circuit elements in three dimensions in linear time. Using an order of magnitude less time, our proposed algorithm produces placements with better than 11% less wire lengths than partitioning placement using the best and fastest partitioner. Due to the algorithms iterative nature, wire-length results can be further improved by increasing the number of iterations.Further, we provide empirical evidence that large circuits benefit most from 3-D technology and that even a small number of layers can provide significant wire-length improvements.