Emerging Technologies of Computation

Montek Singh

COMP790-084Sep 8, 2011

Previous class:◦ Basics of magnetism◦ Nanomagnets and their coupling

TODAY:◦ Challenges and Benefits

reliability and yield speed energy

◦ Open questions clocking? suitable architectures externally controlled inputs? integration with storage?

Today: Magnetic Quantum Dot Cellular Automata (MQCA)

Yield only 25%!

Reliability and yield

Individual gates can function at THz speeds

Clocking limits operation to 100 MHz or so

Speed

Gates extremely energy-efficient◦ dissipation below 1 eV per switching event◦ 10^10 gates would dissipate ~0.1W power

assuming 100 MHz operation◦ Another experiment indicates at least 100x

energy benefit

Clocking dissipates more energy

Energy

Challenge: Clocking

Need complex multiphase clocking

Questions◦ how many phases◦ what phase relationships

Challenge: Clocking

Architectural problems:◦ “layout=timing” problem

how to arrange to maintain data coherence?

◦ how to feed back data values?

◦ can we have a “real data clock” signal as well?

Question: Suitable Architectures?

How to provide external inputs?◦ so far, experiments only provide constants!

Question: providing inputs

Can we combine processing with magnetic storage?◦ smart disks!◦ smart magnetic RAMs (MRAMs)!

Question: integrating w/ storage