1. Montek Singh COMP790-084 Oct 4, 2011

2.  Basics of probabilistic design ◦ energy-correctness tradeoff ◦ probabilistic Boolean logic ◦ approximate arithmetic ◦ applications  Next class: ◦ architectures and design tools ◦ case studies ◦ challenges and benefits ◦ open questions

3.  Operate at reduced voltage ◦ more noise but lesser energy consumption  Where is this acceptable?  Where could this be even desirable?

4.  Logic values have associated probabilities ◦ p: probability that the value is correct  introduces non-determinism

5.  Thermal noise makes any switch noisy ◦ probability of error depends on thermal noise vs. operating voltage

6.  Thermal noise makes any switch noisy ◦ probability of error depends on thermal noise vs. operating voltage  higher supply voltage (Vdd) w.r.t. noise (sigma) implies higher probability of correct logic

7.  Everything else remaining fixed: ◦ energy required goes up exponentially with prob. of correctness ◦ energy required goes up quadratically with noise

8.  energy required goes up exponentially with prob. of correctness

9.  Probabilistic Cellular Automata  Random Neural Networks  Hyper Encryption  Bayesian Inference