Fault-Tolerant Fault-Tolerant Techniques and Techniques and

Nanoelectronic DevicesNanoelectronic Devices

Andy HillAndy Hill

CH E 5480 995CH E 5480 995

AbstractAbstract

Proposed nanocomputers offer Proposed nanocomputers offer faster, more powerful computingfaster, more powerful computing

Problems expectedProblems expected– High manufacturing defect rateHigh manufacturing defect rate– Transient errorsTransient errors

Two possible solutionsTwo possible solutions– Increase manufacturing efficiencyIncrease manufacturing efficiency– Increase device’s capacity for defectsIncrease device’s capacity for defects

Abstract (cont’d)Abstract (cont’d)

Most nanoelectronic device research Most nanoelectronic device research today is devoted to reducing the size today is devoted to reducing the size of devicesof devices

Fault-tolerant technique research Fault-tolerant technique research shows that the reconfiguration shows that the reconfiguration method is:method is:– Can handle the highest defect rateCan handle the highest defect rate– Cannot handle the current defect rateCannot handle the current defect rate– May be impracticalMay be impractical

IntroductionIntroduction

First computer invented had one First computer invented had one function – to solve linear equationsfunction – to solve linear equations

Always a push to be faster, more Always a push to be faster, more powerfulpowerful

Other technologies would aid Other technologies would aid tremendously from more powerful tremendously from more powerful computers computers – MilitaryMilitary– Artificial IntelligenceArtificial Intelligence– Medical / BiologicalMedical / Biological

Literature ReviewLiterature Review

Fault-tolerant techniques have been Fault-tolerant techniques have been studied for over half a centurystudied for over half a century

Research focused on application of Research focused on application of technique technique

Current research focused on Current research focused on techniques for chips with 10techniques for chips with 1012 12 devices devices in 1 square cmin 1 square cm

Lit Review (cont’d)Lit Review (cont’d)

Nanoelectronic device research Nanoelectronic device research mainly focused on producing mainly focused on producing molecular scale devicesmolecular scale devices

Limited research on the production of Limited research on the production of those devicesthose devices

Theoretical BackgroundTheoretical Background

Main fault-tolerant techniquesMain fault-tolerant techniques– Redundancy (RMR, CTMR)Redundancy (RMR, CTMR)– NAND multiplexingNAND multiplexing– ReconfigurationReconfiguration

RedundancyRedundancy

R-fold (RMR) redundancy (R-fold (RMR) redundancy (leftleft) is a function of cascaded triple ) is a function of cascaded triple (CTMR) redundancy ((CTMR) redundancy (rightright))

[1]

Multiplexing / ReconfigMultiplexing / Reconfig

NAND multiplexingNAND multiplexing– Complex system utilizing majority gates Complex system utilizing majority gates

and NAND logicand NAND logic– Adaptive to decreasing manufacturing Adaptive to decreasing manufacturing

effficiencyeffficiency ReconfigurationReconfiguration

– Units not working are detectedUnits not working are detected– Cluster reconfigured accordinglyCluster reconfigured accordingly

Current ResearchCurrent Research

Research comparing techniques Research comparing techniques shows reconfiguration can adapt to shows reconfiguration can adapt to highest defect rates, but may be highest defect rates, but may be impracticalimpractical [1]

Current research (cont’d)Current research (cont’d)

Nanoelectronic devices being Nanoelectronic devices being researched are 100 to 1000 times researched are 100 to 1000 times smaller than current devicessmaller than current devices

[2]

Future DirectionsFuture Directions

Continue research of techniques Continue research of techniques specific to nano-scaled devicesspecific to nano-scaled devices– Determine practicality of reconfigurationDetermine practicality of reconfiguration

Continue research developing Continue research developing nanoelectronic devicesnanoelectronic devices

Research the efficiency of mass Research the efficiency of mass producing devicesproducing devices

ReferencesReferences

[1] - K Nikolic, A Sadek and M Forshaw [1] - K Nikolic, A Sadek and M Forshaw 2002 Fault-tolerant techniques for 2002 Fault-tolerant techniques for nanocomputersnanocomputers NanotechnologyNanotechnology 1313 357-362 357-362

[2] - Goldhaber-Gordon D. [2] - Goldhaber-Gordon D. et al.et al. 1997 1997 Overview of Nanoelectronic Devices Overview of Nanoelectronic Devices Proceedings of the IEEE Proceedings of the IEEE 8585 (4) (4)