1. L-Shaped RST Routing Perform L-RST using node b as the root
First step: build a separable MST
Prim with w(i,j) = (D(i,j), −|y(i) − y(j)|, − max{x(i), x(j)})
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2. First Iteration
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3. Separable MST Construction
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4. Separable MST Construction (cont)
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5. Constructing a Rooted Tree
Node b is the root node
Based on the separable MST (initial wirelength = 32)
Bottom-up traversal is performed on this tree during L-RST routing
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6. Partial L-RST for Node C
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7. Partial L-RST for Node E
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8. Partial L-RST for Node G
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9. Partial L-RST for Node D
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10. Partial L-RST for Node D (cont)
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11. Partial L-RST for Node F
best case
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12. Partial L-RST for Node F (cont)
best case
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13. Processing the Root Node
best case
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14. Top-down Traversal In order to obtain the final tree upper upper lower
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15. Final Tree Wirelength reduction
Initial wirelength − total overlap = 32 − 4 = 28
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16. Stable Under Rerouting
Steiner points are marked X
Wirelength does not reduce after rerouting
Practical Problems in VLSI Physical Design