1. CS294-6 Reconfigurable Computing Day 3 September 1, 1998 Requirements for Computing Devices

2. Today What elements are required for GP/post- fabrication computing? What do we expect out of a GP computing device? How should we characterize a GP computing device?

3. Requirements In order to build a general-purpose computing device, we absolutely must have? –_

4. Desirable We general expect a general-purpose computing device to provide: –_

5. Characterize How traditionally characterized? Problems require same mix of constituent components?

8. Primitive compute elements enough?

11. Compute and Interconnect

12. Sharing Interconnect Resources

13. Sharing Interconnect and Compute Resources What role are the memories playing here?

14. Memory block or Register File Interconnect: moves data from input to storage cell; or from storage cell to output.

15. What do I need to be able to use this circuit properly? (reuse it on different data?)

17. Requirements In order to build a general-purpose computing device, we absolutely must have? –Primitive to compute a function of multiple input bits –Interconnect: space –Interconnect: time –Instructions -- describe above –I/O -- get data in and out of device

18. Where are our basic computing elements in a Universal Turing Machine?

22. Desirable We general expect a general-purpose computing platform to provide: –Get Right Answers :-) –Support large computations -> need to virtualize physical resources –Software support, programming tools -> higher level abstractions for programming –Automatically store/restore programs –Architecture family --> compatibility across variety of implementations –Speed -> … new hardware work faster

23. Desirable We general expect a general-purpose computing device to provide: –(how is this question different than previous?)

24. Expect from GP Compute? Virtualize to solve large problems –robust degradation? Computation defines computation Handle dynamic computing requirements efficiently Design subcomputations and compose

25. Solve Any Virtualize –store state instruction –sequence –select predictability lead time load bandwidth

26. Data Dependent Computation Cannot reasonably take max over all possible values –bounds finite, but unbounded –“malloc” maximum memory? Computations unfold during execution Computation dramatically different based on data

27. Compose Abstraction is good Design independent of final use Use w/out reasoning about all implementation details Link together subcomputations to build larger