Problems / Clock Tree Synthesis / Non-default-rule clock routing

Non-default-rule clock routing

Clock Tree Synthesis medium interactive · in-browser

Non-default-rule (NDR) clock routing. The clock trunk runs a long way and must arrive clean, so it is routed with a non-default rule instead of a normal signal wire.

  • Transition (slew) - widen the trunk to cut its resistance and clean up the transition.
  • Crosstalk delay - add spacing or grounded shield wires between the trunk and the aggressor nets beside it to cut coupling.
  • Routing tracks in budget - width, spacing, and shields all spend routing tracks, so you cannot over-build.

Find the width, spacing, and shielding that clears slew and crosstalk inside the track budget, then Submit design.