6_unit5B

Chang, Huang, Li, Lin, Liu Unit 5B: Floorplanning
Pentium 4
PowerPC 604Unit 5B Chang, Huang, Li, Lin, Liu Floorplanning
Chang, Huang, Li, Lin, Liu Early Layout Decision Example
Pentium 4
PowerPC 604Early Layout Decision Methodology
Chang, Huang, Li, Lin, Liu
Unit 5B6
Chang, Huang, Li, Lin, Liu
7
Chang, Huang, Li, Lin, Liu Floorplanning Concepts
a cell
a cell
entire IC is the highest-
leaf cell
composite cell 8
Chang, Huang, Li, Lin, Liu Slicing Floorplan + Slicing Tree
are obtained by a horizontal (except for the top-level cell)
H
V
H
H:horizontal cut V:vertical cut different from the definitions in the text!!
the same.
Unit 5B9
Chang, Huang, Li, Lin, Liu
Slicing Floorplan Design by Simulated Annealing
-1, # operands > # operators.
Polish expression ↔Postorder traversal.
: rectangle i on bottom of j; ijV: rectangle i
Chang, Huang, Li, Lin, Liu
Question:How to eliminate ambiguous representation?
Chang, Huang, Li, Lin, Liu
Chang, Huang, Li, Lin, Liu
Adjacent:1 and 6 are adjacent operands; 2 and 7 are adjacent operands; 5 and V are adjacent operand and
․Question:The balloting property holds during the moves?
⎯M1and M2moves are OK.
⎯Check the M3moves!Reject “illegal”M3moves.
․123
4
Chang, Huang, Li, Lin, Liu ․φ= A + λW .
⎯λ: user-specified parameter
W = ∑ij c ij d ij .
c ij : # of connections between blocks i an
d j .
d ij : center-to-center distanc
e between basic rectangles i and
Chang, Huang, Li, Lin, Liu Wiring cost?
Center-to-center interconnection length
•Allow rotation
Unit 5B Chang, Huang, Li, Lin, Liu
Incremental Computation of Cost Function (cont'd)
Unit 5B
Chang, Huang, Li, Lin, Liu
Annealing Schedule
․Initial solution: 12V3V (V)
1 begin
T 0←uphill ←reject 7 SelectMove(M of
+1);
cost (NE ) -cost Random < )uphill ←uphill Chang, Huang, Li, Lin, Liu Shape Curve
․Flexible cells imply that cells can have different aspect ratios.y =sx
y legal shapes
y x
x y
Shape Curve (cont’d)
y
x
The shape function of a 2 ×4 inset cell.
Chang, Huang, Li, Lin, Liu
Shape Curve (cont’d)
Chang, Huang, Li, Lin, Liu
Addition for Vertical Abutment
Unit 5B25
Chang, Huang, Li, Lin, Liu
Deriving Shapes of Children
Chang, Huang, Li, Lin, Liu
Sizing Algorithm for Slicing Floorplans
regions.
Unit 5B
Chang, Huang, Li, Lin, Liu
Unit 5B Chang, Huang, Li, Lin, Liu Wheel or Spiral Floorplan
․This floorplan is not slicing!․Wheel is the smallest non-slicing floorplans.
Chang, Huang, Li, Lin, Liu Order-5 Floorplan Examples
V V
H
Unit 5B Chang, Huang, Li, Lin, Liu General Floorplan Representation: Polar Graphs ․edge (weight): cell/block/module (dimension).
vertical horizontal polar graph
Chang, Huang, Li, Lin, Liu B*-Tree for Compacted Non-Slicing Floorplans Chang et. al., “B*-tree: A new representation for non-slicing
and its induced B*-tree.
B*-tree Packing ․
Chang, Huang, Li, Lin, Liu
Partition a rectilinear module into rectangular sub-modules.
location constraints for the sub-modules.
E.g., Keep the right sub-module as the left child in the B*-tree. Treat the sub-modules of a module as a whole during processing
Chang, Huang, Li, Lin, Liu
More on Soft Modules More on Soft Modules
More on Soft Modules
mm2).
Chang, Huang, Li, Lin, Liu。