Hardware-Software Interaction: Preliminary Observations

1. Hardware-Software Interaction:Preliminary Observations Neil Steiner and Peter Athanas12th Reconfigurable Architectures Workshop (RAW 2005)Denver, ColoradoApril 4, 2005

2. Conceptual Interpretation Animation http://www.ccm.ece.vt.edu/hsi/documents/hardware-software-interaction.mov

3. Introduction & Motivation Foreword • Software viewed as a form of information • Information viewed as non-physical • Discussion not restricted to digital computing • Not about co-design (fundamentals, not just complexity)

4. Introduction & Motivation Background • Progression from computational aids to calculators, to programmable machines, to configurable machines • Lines between hardware and software are getting blurred – both perform functions – are they interchangeable counterparts? • Properties or behaviors at hardware-software interface could have profound effects • No evidence of related work in literature • No recognized experts or definitive references

5. Case Study Boundaries 2-input look-up table

6. Case Study Boundaries 2-input look-up table

7. Case Study Boundaries 2-input look-up table

8. Case Study Boundaries 2-input look-up table

9. Proposed Hypothesis Duality Hardware Physical structure, fixed, tangible Storage Flip-flop, DRAM, capacitor, switch, electron spin Connection Wire, fiber, RF link, entangled photons Logic Digital gate, op amp, quantum molecular gate Information Non-physical structure, flexible, intangible Software Instructions or data; persistent information Signal Logical connection; Non-persistent information Operation Process applied to information

10. Observations and Properties Information “A Mathematical Theory of Communication” Claude Shannon, Communications “Information is Physical” Rolf Landauer, Thermodynamics “Information is Protophysical” Doug Matzke, Quantum Mechanics “What is Information?” Andrzej Chmielecki, Philosophy Uncertainty or Determinism? Physicists, Quantum Mechanics, Quantum Gravity

11. Observations and Properties Structure

12. Observations and Properties Structure • Structure is an ordering of parts, i.e. relational information • Takes building blocks and assembles or connects them into larger grouping • Structure is compressible • Structure is an information carrier • Identical structures lead to isomorphisms • Structure depends upon forces for cohesion • Must be designed and built – requires energy • Has a measure of fragility or transience

13. Contrasts with Structure Randomness

14. Contrasts with Structure Randomness • Randomness is the absence of structure • Randomness is not compressible (structured arrangement follows rules and can be expressed in a more compact form) • Randomness is robust – perturbing it does not create structure • True randomness is difficult to find or prove – unpredictability isn’t necessarily randomness • Nature removes structure at no cost • We remove structure at the cost of energy

15. Logical and Spatial Structure Topology

16. Logical and Spatial Structure Topology • Topology as structure of the interface – structure may be physical or non-physical • Informational laws as topological constraints • Software requires a substrate, but that substrate need not be hardware – consider software emulation • The substrate only has to provide the proper topology or structure • Mismatches result in undesirable behavior • Robust systems – closely matched topologies

17. Interface Properties Boundaries

18. Interface Properties Boundaries • Boundaries – discontinuities – interfaces • Boundary conditions can be significant: • Electromagnetics – boundaries provide constraints • Differential equations – boundaries specify problem • What boundary properties or behaviors exist at hardware-software interface? • Continuity properties? • Surface-normal properties? • Mismatch reflections? • Work functions?

19. Comments and Questions Summary

20. Comments and Questions Summary • No structure without forces – no topology or interface or boundaries without structure • Computation involves an interface between physical hardware and non-physical software • What preserves the interface? Is there some “force” or “energy”? Something that we can put to use? Can we control or influence the interface? • Starting from known edges in hopes of eventually reaching area of interest

21. Questions? Further information available at http://www.ccm.ece.vt.edu/hsi