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Floorplanning of Pipelined Array (FoPA) Modules using Sequence Pairs. Matt Moe Herman Schmit. Outline. Pipelined Arrays Previous Sequence Pair work Sequence Pair additions Results. Cryptography. Control. Signal Processing. Microprocessor. Memory. System of the Future.
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Floorplanning of Pipelined Array (FoPA) Modules using Sequence Pairs Matt Moe Herman Schmit
Outline • Pipelined Arrays • Previous Sequence Pair work • Sequence Pair additions • Results
Cryptography Control Signal Processing Microprocessor Memory System of the Future • Soft IP cores • hardware accelerators • pipelined arrays
Logic Logic Logic Pipelined Arrays Logic • Systolic architecture • Easy to compile to • Fast throughput aftersynthesis • Structure lost duringphysical design pipeline stage Logic array adjacent pipelinestages Logic
Logic Logic Logic Physical Design of Pipelined Arrays • Maintain structure • One pipeline stage =one floorplan module • Use floorplanning tools to create placement constraints floorplan module array adjacent modules
How do you maintain the structure? • If modules were the same size - trivial solutions 1 1 9 1 8 9 2 3 2 8 2 7 6 4 3 7 5 6 4 6 3 4 5 7 8 9 5
More interesting problem… • Modules vary in size • Wire Congestion • Created by non-adjacencyof modules • Forces extra areausage 0 8 11 7 10 9 1 6 5 2 3 4
Classic Simulated Annealing of Sequence Pairs • Sequence Pair • Floorplan representation that describes directional constraints between every possible pair of blocks • Large design space • H. Murata, et.al., “VLSI Module Placement Based on Rectangle Packing by the Sequence Pair,” IEEE Trans. on Computer Aided Design of Integrated Circuits and Systems, vol. 15, no. 12, pp. 1518-1524, December 1996.
A B C D A D C B Classic Swap Move B A A B C C D A D C B A B C D D A C B D A CB D
A B C D ABCD DACB Oblique Constraint Graph Oblique Connnectivity Graph B B A A C C A B C D A B C D D A C B D A C B D D
A B C D B A C A B C D D A C B D FoPA Delete / Insert Move A C B A B C D D B AC D A C B D
A B C D B A C A B C D D A C B D Restricted Delete / Insert Move C B A A C B D D A C B D A C B D
This looks better… • All logically array adjacent elements are adjacent in thefloorplan • Reduced wirecongestion 9 8 7 10 11 6 3 4 5 2 1 0
Floorplanning Results • Block sizes created from fastest synthesized designs • Each point represents the best score from 10 annealing runs
Results afterPlacement and Routing • Floorplans used as constraints in Monterey Design System’s Dolphin • Iteratively expand floorplans by 1% until routable • Delay reported by Dolphin
Conclusions • New restricted move set • Creates better placement of modules during floorplanning synthesis • Creates smaller and faster designs after placement and routing • In paper • New wire length model • Cost Metric