CS 258F Class Project Spring 2003

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CS 258F Class ProjectSpring 2003

• Prof. Jason Cong

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Project Description

• Input
• Netlist given in bookshelf format
• Global placement for the netlist with overlaps
• Output
• An overlap free detailed placement with
  wirelength optimized
• Constraint
• Cells should be put on the standard cell rows

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Global Placement
The global placement solutions are derived by
snapping detailed Placement results into
pre-defined bins
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Bookshelf Format

• .aux
• List of the component file names of the problem
  instance
• .nodes
• Describe the dimension of each cell
• .net
• Description of each net, i.e. the pins it
  connects and their relative locations on each
  node
• .pl
• Describes the location and orientation of each
  cell. It gives the global placement information
• .wts
• Describes the weights associated with each net
• .scl
• Describes the layout of standard cell rows

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Bookshelf Example

• .nodes
• C1 32 32
• C2 64 32
• C3 32 32
• .pl
• C1 200 200 N
• C2 232 200 N
• C3 296 200 N

• .nets
• NetDegree 3
• C1 I 16 16
• C2 O 32 16
• C3 O 16 16
• NetDegree 2
• C2 I 16 16
• C3 I 32 16

64
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Bookshelf Example

• CoreRow Horizontal
• Coordinate 32
• Height 32
• Sitespacing 32
• SubrowOrigin 32 NumSites 100

3200
32
32
32
http//vlsicad.ucsd.edu/GSRC/bookshelf/Slots/Place
ment/plFormats.html
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Parser Description

• Class Pin
• x, y relative location to the LL corner of
  each cell
• cellPtr pointer to the owner cell
• netPtr pointer to the owner net
• dir direction of each pin
• Class Net
• id, name identifier
• pinList vector of pins it connects
• Class Cell
• id, name identifier
• wth, hgt dimension of the cell
• x, y LL corner of the cell
• pad True if the cell is a pad, False
  if the cell is movable
• pinList vector of pins on the cell
• Class SingleRow
• lowerLeftX, lowerLeftY starting position of a
  row
• width, height height is the height of standard
  cell

Location /u/class/u/class/cs258f/2003_spring/pars
er
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Circuit Description

• Pekoxx circuits
• Uniform sized cells
• Known optimal wirelength
• Initial detailed placement by optimal solution
• Ibmxx circuits
• Non-uniform sized cells
• Optimal wirelength unknown
• Initial detailed placement by Dragon

http//ballade.cs.ucla.edu/pubbench/placement/
http//www.cs.ucla.edu/xjyang/Dragon/ibm-place.ht
ml
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• The End