Emerging Technologies of Computation

Montek Singh

COMP790-084Nov 29, 2011

What is Brownian motion?

Brownian Cellular Automata◦ Asynchronous Cellular Automata

Mapping Circuits to Brownian Cellular Automata◦ Basic building blocks◦ Higher-level building blocks

Benefits and Challenges

Today: Brownian Circuits

Neighborhood determines a cell’s next state

Timing:◦ synchronous◦ asynchronous

Review of Cellular Automata

Transition rules example:

Brownian Cellular Automata

Reversible: both directions possible◦ hence: “Brownian”

Linear “signal” propagation

Signal comes in from any of 3 directions◦ goes out on any of 3 directions◦ possibly same one!

Configuration 1: A “Hub”

2 horizontal signals 2 vertical signals

Configuration 2: A “Cjoin”

Allow one-way motion only◦ reverse rotation is blocked

Electronic equivalent = diode

What’s a Ratchet?

Allows one-way propagation only

Configuration 3: Ratchet

Symbolic representation:

Summary: 3 basic configurations

We need these 3 useful higher-level blocks:

What do we need?

Build using basic configurations

Build using basic configurations

Build using basic configurations

Build using basic configurations

Build using basic configurations

Build using basic configurations

Possible to get around the timing/clocking problem◦ use asynchronous cellular automata

Brownian motion desirable◦ for backtracking◦ possibly for exploring solution space??

How to implement?◦ still in its infancy◦ harness noise and fluctuations

Benefits and Challenges