Delivering On-chip Bandwidth Off-chip and Out-of-box with Proximity and Optical Communication

  • Ashok V. Krishnamoorthy
  • Jon Lexau
  • Xuezhe Zheng
  • John E. Cunningham
Part of the Integrated Circuits and Systems book series (ICIR, volume 0)


While copper-based electrical Serdes links have, to date, dominated the domain of ultra-short reach interconnects, future high-performance computers may require the integration of diverse interconnect technologies. In previous chapters, various forms of proximity communication that can provide low-energy chip-to-chip links between adjacent chips have been described. The strengths of proximity communication lie in low-energy short-distance links; the strengths of optical communication lie in efficiently reaching longer distances. Here we look to combine these technologies in a new hybrid I/O platform that can deliver balanced bandwidth on-chip, off the chip and even out of the box. In this chapter we will introduce the concepts of an optical-to-proximity interface chip, and review results from an experimental 90 nm test chip that integrates three types of high-speed chip-to-chip interconnects: capacitive interconnects for proximity communication; optical interconnects employing vertical-cavity surface-emitting lasers (VCSELs) and photodiodes; and electrical interconnects using current-mode logic (CML). We will discuss the operation and compatibility of each interconnect modality, and review interface requirements, chip layout considerations and test results.


Optical Communication Optical Link Test Chip Optical Interconnect IEEE Photonic Technology Letter 


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Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  • Ashok V. Krishnamoorthy
    • 1
  • Jon Lexau
    • 2
  • Xuezhe Zheng
    • 1
  • John E. Cunningham
    • 1
  1. 1.Sun Microsystems Chief Technology OrganizationSan DiegoUSA
  2. 2.Sun Microsystems Research LabsMenlo ParkUSA

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