Towards Global Routing with RLC Crosstalk Constraints

1
Towards Global Routing with RLC Crosstalk
Constraints

• J. D. Z. Ma, L. He
• DAC 2002

2
Outline

• Introduction
• Noise model
• Algorithm
• Experiments
• Conclusion

3
Global routing

• Over-the-cell routing
• 2 layers, vertical / horizontal

4
Steiner tree
5
Inductive coupling model
6
LSK model

• Length-scaled Keff
• SPICE simulation
• 1020 noise
• Table lookup (LSK vs. noise volt)

7
Algorithm

• Phase 1
• Derive crosstalk bound
• Global routing
• Phase 2
• SINO
• Phase 3
• Violation, congestion removal

8
Phase 1 crosstalk bound

• Determine LSK
• Derive Kth for each net segment
• Kth is the max bound of the path

9
Adjacency graph model
t2
s
t1
t3
10
Iterative deletion algorithm
11
Shield estimation

• of shield is proportional to sensitivity

12
Phase 2 SINO

• SINO/GC graph coloring
• SINO/SA simulated annealing
• Discussed in previous presentation

13
Phase 3
14
Experiments

• IDNO
• iSINO
• GSINO

15
Crosstalk violation ratio
16
Wire length overhead
17
Area overhead
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Conclusion

• Global routing infrastructure
• 3 phases approach
• of shields estimation
• More info will be in TVLSI
• Reroute technique seems to be weak