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Show 8 currently no computer aids for generating data-paths or control-units r-epr-eaentied in PPL from higher levels of abstraction, much of the software generated during the course of the project will be directly related to PPL, data-paths and control-units. 1.4 Synchronous Speed-Independent Systems The MIT Data Path Generator project, the LAVA project and the Caltech Silicon Structures Project all deal primarily with synchronous logic. Control-uni ts are generated using the PLA and using clocked registers for holding state variables. Data-paths are often generated using two-phase dynamic shift-registers and other clocked elements. The primary assumption being made in all these efforts is that synchronous systems will always work. While it Ls . true that synchronous systems currently work well, C. L. Seitz of Caltech has postulated that as integrated circuit device dimensions scale down, timing will become such. a problem. that working globally clocked systems will be impossible to design and .implement [64J. If future advances in integrated circuit technology and circuit implementation techniques do indeed seal the tomb on fully synchronous systems, the above mentioned research projects on datapath and systems design will have generated some ideas 'Which may be used within Seitz's equipotential regions, but will not aid in either data transfer between such regions or global and inter-equipotential:- egion controJ.. These problems can only be solved through speed-independent |
