Montek Singh COMP Sep 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?
Yield only 25%!
Individual gates can function at THz speeds Clocking limits operation to 100 MHz or so
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
Need complex multiphase clocking
Questions ◦ how many phases ◦ what phase relationships
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?
How to provide external inputs? ◦ so far, experiments only provide constants!
Can we combine processing with magnetic storage? ◦ smart disks! ◦ smart magnetic RAMs (MRAMs)!