EQ-Sequences%20for%20Coding%20Floorplans

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Title and Authors
EQ-Sequences for Coding Floorplans
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1. Introduction -1
A floorplan is a dissection of a rectangle
called chip into smaller rectangles called rooms
by horizontal and vertical line segments, which
meet in T-junctions.
The floorplanning contains

• Encoding (to represent floorplans)

• Moving (to transform floorplans)

• Decoding (to realize floorplans).

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1. Introduction -2
In order to generate and evaluate candidate
floorplans to determine the best floorplan
encountered so far, floorplans should be
represented by codes that satisfy the followings

• Any feasible floorplan can be represented by an
  unique code

• The code is decoded to one and only one floorplan

• Code moving can be efficiently implemented

• Abutment relationships of two rooms can be
• checked out before decoding or while moving.

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1. Introduction -3
In this paper, we propose a new code for
representing a floorplan called EQ-sequence,
which can be considered as an Extension of a
Q-sequence.
The advantages of EQ-sequence

• Any floorplan with different adjacent
  relationships of rooms can be encoded by a unique
  EQ-sequence and an EQ-sequence can be decoded to
  a unique floorplan, both are in O(n) time.

• Whether two rooms is connected (abut) or not can
  be checked while moving the EQ-sequences.

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2. BASIC CONCEPTS-1 (Walls and Prime Seg)
The segments enclosing the chip as walls
particularly are called right-wall(WR), left-wall
(WL), top-wall (WT ) and bottom-wall (WB).
WT
For any room r, two segs meet at the
right-bottom corner of r and one ends there
forming a T-junction. The seg that ends at the
T-junction is called the prime seg of r, denoted
by pr. Note that the right-bottom room has not a
prime seg.
WR
WL
WB
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2. Basic Concepts-2 (Q-sequence)
Q-sequence is a concatenation of the states of
rooms (WL or WT), represented by a sequence Q(r)
(Q(WL) or Q(WT)). Q(r) (Q(WL) or Q(WT))
has the one of the patterns (agtbgtc