1 / 22

I. Floorplanning with Fixed Modules

I. Floorplanning with Fixed Modules. Fixed modules only, no rotation allowed m 1 (4,5), m 2 (3,7), m 3 (6,4), m 4 (7,7). ILP Formulation. Non-Overlapping Constraints (cont). Additional Constraints. Solutions. Using GLPK we get the following solutions:. Final Floorplan.

jsoria
Download Presentation

I. Floorplanning with Fixed Modules

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. I. Floorplanning with Fixed Modules • Fixed modules only, no rotation allowed • m1 (4,5), m2 (3,7), m3 (6,4), m4 (7,7) Practical Problems in VLSI Physical Design

  2. ILP Formulation Practical Problems in VLSI Physical Design

  3. Non-Overlapping Constraints (cont) Practical Problems in VLSI Physical Design

  4. Additional Constraints Practical Problems in VLSI Physical Design

  5. Solutions • Using GLPK we get the following solutions: Practical Problems in VLSI Physical Design

  6. Final Floorplan • Why the non-optimality? • Due to linear approximation of area objective (= y*) • Chip width/height constraints also affected • In fact, our ILP solution (y* = 12) is optimal under these conditions. Practical Problems in VLSI Physical Design

  7. II. Floorplanning with Rotation • Fixed modules, rotation allowed • Fixed modules: m1 (4,5), m2 (3,7), m3 (6,4), m4 (7,7) • Need 4 more binary variables for rotation: z1, z2, z3, z4 • We use M = max{W,H} = 23 Practical Problems in VLSI Physical Design

  8. ILP Formulation Practical Problems in VLSI Physical Design

  9. Non-Overlapping Constraints (cont) Practical Problems in VLSI Physical Design

  10. Non-Overlapping Constraints (cont) Practical Problems in VLSI Physical Design

  11. Additional Constraints Practical Problems in VLSI Physical Design

  12. Solutions • Using GLPK we get the following solutions: Practical Problems in VLSI Physical Design

  13. III. Floorplanning with Flexible Modules • 2 Fixed modules: • m1 (4,5), m2 (3,7) (rotation allowed) • 2 Flexible modules: • m3: area = 24, aspect ratio [0.5, 2] • m4: area = 49, aspect ratio [0.3, 2.5] Practical Problems in VLSI Physical Design

  14. Linear Approximation Practical Problems in VLSI Physical Design

  15. Linear Approximation (cont) Practical Problems in VLSI Physical Design

  16. Upper Bound of Chip Dimension Practical Problems in VLSI Physical Design

  17. Non-Overlap Constraint Practical Problems in VLSI Physical Design

  18. Non-Overlap Constraint (cont) Practical Problems in VLSI Physical Design

  19. More Constraints Practical Problems in VLSI Physical Design

  20. Solutions Practical Problems in VLSI Physical Design

  21. Comparison • Fixed modules only = 12 × 12 • Rotation allowed = 11 × 11 • Flexible modules used = 10.46 × 10.32 Practical Problems in VLSI Physical Design

  22. Approximation Error and Overlap • Due to linear approximation • Approximated area of m3 = 3.46 × 5.2 = 17.99 (actually 24) • Approximated area of m4 = 3.83 × 7.32 = 28.04 (actually 49) • Real area of m3 = 3.46 × 6.94 = 24 • Real area of m4 = 3.83 × 12.79 = 49 • Floorplan area increases, overlap occurs Practical Problems in VLSI Physical Design

More Related