A 100 Mbps, LED Through-Wafer Optoelectronic Link for Multicomputer Interconnection Networks

Abstract

Through-wafer optoelectronic interconnect offers some architectural alternatives that are not available with wire-based interconnects. In order to compete with wire-based technologies, optoelectronic interconnects must provide reasonable performance in terms of bandwidth, bit error rate (BER), and power, using inexpensive and manufacturable devices. This paper presents a 100 Mbps link design under development as part of a scalable three-dimensional multicomputer network for a 4096 node system. Empirical and analytical data for emitters, detectors, receivers, and optical coupling is used to examine the tradeoffs between link power and bit error rate (BER). Because multicomputer networks demand extremely low BERs (10–15–10–20),hop-by-hoperror correction circuitry is incorporated to optimize BER, providing a robust channel. This approach employs a novel adaptation of the widely used wormhole routing protocol to minimize overhead and maximize compatibility with existing interconnect techniques.