Running Incremental Place and Route - 2021.2 English

Vivado Design Suite User Guide: Implementation (UG904)

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2021.2 English

After the reference checkpoint is read by Vivado, the following actions are taken:

  • Physical optimizations that match the ones in the reference run are carried out on the incremental design automatically.
  • The netlist in the incremental design is compared to the reference design to identify matching cells and nets.
  • Placement from the reference design checkpoint is reused to place matching cells in the incremental design.
  • Routing is reused to route matching nets on a per-load-pin basis. If a load pin disappears due to netlist changes, then its routing is discarded, otherwise it is reused. Therefore it is possible to have partially-reused routes.

Incremental placement and incremental routing might discard cell placements and net routes instead of reusing them, if it helps improve routability of the netlist or helps maintain performance comparable to that of the reference design.

Design objects that do not match between the reference design and the current design are placed after incremental placement is complete and routed after routing is complete.