1. Routing of Analog Busses with Parasitic Symmetry Lars Schreiner, Markus Olbrich, Erich Barke, Volker Meyer zu Bexten

2. Lars Schreiner: ISPD 20052 Contents Motivation Net Bundle Routing Trapezoid Methodology Results Conclusions/Future Work

3. Lars Schreiner: ISPD 20053 Contents Motivation Net Bundle Routing Trapezoid Methodology Results Conclusions/Future Work

4. Lars Schreiner: ISPD 20054 Motivation Groups of wires (net bundles) have to be routed symmetrically -Symmetry = equal capacitive coupling and resistance for each wire Automatic balancing of wire length Automatic generation of shielding patterns Automatic generation of slotted/split wires

5. Lars Schreiner: ISPD 20055 Example of a Net Bundle with Parasitic Symmetry

6. Lars Schreiner: ISPD 20056 Contents Motivation Net Bundle Routing Trapezoid Methodology Results Conclusions/Future Work

7. Lars Schreiner: ISPD 20057 Steps of Net Bundle Routing Calculation of virtual terminals and net order Path search for net bundle Routing of the net bundle to the terminals Calculation of wire length differences and adjustment area search Use of Module generator for wire implementation 1 2 3 4

8. Lars Schreiner: ISPD 20058 Basic Procedure T2a T2b T1a T1b = Virtual Terminal = Terminal 1234

9. Lars Schreiner: ISPD 20059 Separation of Terminal/Net Bundle Routing Nets are treated and routed together as bundles. Technology independent module generators can be used. Problem complexity is reduced. Keeping symmetry is easier.

10. Lars Schreiner: ISPD 200510 Net Ordering During Path Search (1) „False“ net order of the right terminal bundle Consideration during path search necessary terminal bundle virtual terminal 1 2 31 2 3 123 BUS-module from Module generator

11. Lars Schreiner: ISPD 200511 Net Ordering During Path Search (2) Possible solution of example 1 2 31 2 3 123

12. Lars Schreiner: ISPD 200512 Contents Motivation Net Bundle Routing Trapezoid Methodology Results Conclusions/Future Work

13. Lars Schreiner: ISPD 200513 T- and L-Structures of Trapezoid Methodology = = Generator call: BUS N=3 LENGTH=4e-5 WIDTH=5e-6 LAYER=2 BEVELSTART=45 BEVELEND=0 -45° 0°

14. Lars Schreiner: ISPD 200514 Benefits of Trapezoid Methodology Universal use for many geometries -Lines, T- and L-structures are implemented by the same module generator Technology information hidden in module generator -Router gets only necessary technology information -Shielding and Slotting are hidden in the generator Easy maintainability and adaptation to new technologies

15. Lars Schreiner: ISPD 200515 Adjustment Modules Shorter wires have to be stretched Two cases: -Adjustment to the favorable site -Adjustment to the unfavorable site Problem: Bent or terminal connection Solution: Adjustment modules

16. Lars Schreiner: ISPD 200516 Examples of Adjustment Modules

17. Lars Schreiner: ISPD 200517 Benefits of Adjustment Modules Wire length balancing is done by module generator. Different net bundle modules are generated for balancing bents, asymmetries, etc. Resistive differences are adjusted. Capacitive balancing is possible.

18. Lars Schreiner: ISPD 200518 Contents Motivation Net Bundle Routing Trapezoid Methodology Results Conclusions/Future Work

19. Lars Schreiner: ISPD 200519 Hand Made vs. Router

20. Lars Schreiner: ISPD 200520 Symmetric Coupling Consideration During Path Search

21. Lars Schreiner: ISPD 200521 Contents Motivation Net Bundle Routing Trapezoid Methodology Results Conclusions/Future Work

22. Lars Schreiner: ISPD 200522 Conclusion Routing of net bundles Consideration of routing constraints -Parallel wires -Symmetric capacitive coupling -Wire length difference calculation -Symmetric terminal connection Module generators -Trapezoid methodology -Adjustment modules

23. Lars Schreiner: ISPD 200523 Future Work 45° Routing Twisted wires Inductances