Optical interconnects in the Touchstone supercomputer program

ABSTRACT An optical interconnect has been designed for the Touchstone supercomputer program. The objective of the system is to demonstrate scalability of the Touchstone 2-D interconnect mesh and enhance system performance. The name of the opticalinterconnect system is the Fiber Optic Mesh Extender (FOME). The goal of this work to to demonstrate that fiber optics canprovide physical scalability in parallel supercomputing. Two ASICs were designed to control the fiber optic transmitter andreceiver now under development at Honeywell's Microswitch division. This paper describes the FOME design including systemarchitecture, planned implementation, and the resulting VHDL behavioral description. 1. INTRODUCTION Optical interconnects are a potential solution to the interconnect problems that arise as parallel processors require significantlyhigher bandwidth per interconnect and/or higher interconnect density1' 2• This paper describes the architecture, design, andplanned implementation of a gigabit per second (Gbps) optical interconnect system for a parallel supercomputer developed byIntel on the Touchstone program. The optical interconnect work is being done primarily by Honeywell, with support from Intel,who is providing system level expertise and a demonstration system.The program merges system-driven requirements with technology development. The system-driven aspect ensures that the finaldesign will meet performance and functionality specifications, and addresses such issues as electrical performance, interfacesignals, mechanical characteristics, manufacturability, and cost. The objective of the program is to provide scaiability for parallelprocessors through the use of Gbps optical interconnects. Prototype hardware will be demonstrated. The implementation must