Thursday, 21 October 2010

Static Discipline, a model?

  1. Lumping things together simplifies things.
  2. Noise is a fact of life.
  3. Digital abstraction helps with noise.
  4. Reading things at a distance adds noise.
  5. Black and white is nice and simple but what's the point?
  6. The sender is interested in sending a signal to the receiver.
  7. There is an agreement between them that the receiver will receive high and low values only.
  8. The agreement between sender and receiver means there is better noise immunity.
  9. However if you don't have a noise margin you don't know how much noise can be tolerated.
  10. Too rigid a signal criteria doesn't allow for any noise margin.
  11. You have to define 'No man's land' - The forbidden region.
  12. I am going to discipline myself to playing in this 'Playground' and that is how I am going to define my rules.
  13. Stay within the boundaries and all rules apply.
  14. It is a discipline, there is no logic to it. just do it and you will be ok.
  15. The receiver can do whatever they want when they receive a sifgnal from the Forbidden Region. Burn it, ignore it, anything. No one cares you can add any value you want.                                    We still have a problem though.
  16. There is no margin for noise. Back to the drawing board folks.
  17. So let's allow the receiver to still receive the same values, values it understands but what I do is make the sender operate under tougher standards.
  18. The sender has narrow margins but allows for noise to be included.
  19. The receiver then can never see a value in the Forbidden Region. That is the beauty of using this discipline.
  20. So in the playground there is a region that only deals with high and low values.
  21. I am only going to focus on those values in the Forbidden Region.
  22. If there is a signal in the Forbidden Space then my behaviour is underfined.
  23. I don't care, want to go there, sure go there. I don't know what is going to happen to you.
  24. We are artists right? We have disciplined ourselves to play in this playground. I tell my 9 yearold "Don't go there." 
  25. A big system wants all the parts to have the same noise margins.
  26. It is very hard to have a practical system with a small Forbidden Region.
  27. This is called a 'Static Discipline'.
  28. If inputs meet input thresholds then outputs should meet output thresholds.
  29. A Static Discipline encodes the thresholds that the systems must follow in order for all to communicate.
  30. The larger the noise margin the better you can tolerate noise.
  31. For consumer markets the products may have relatively poor noise margins.
  32. You can process the signal with logic True or False or with numbers.
  33. Combinational Logic Circuit, the output is dependant at all times on the combination of its inputs and if one of its inputs condition changes state so does the output as combinational circuits have "no memory", "timing" or "feedback loops".
  34. The Andgate will enable the receiver to receive a stable, constant, disciplined signal even if their is noise added to the signal.
This is an edited transcription from a lecture on Digital Abstraction by Anant Agarwal of MIT, The only term I have altered is engineer ( electronic) for artist, highlighted in read.  This lectutre is for budding electronic engineers learning how systems communicate different power values. It is a good signifier for me that there are substantial cross disciplinary areas to discuss and explore. You can see the whole lecture with all the graphs and numeric values here at Cosmolearning

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