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AR# 56270

2013.1 Series-7 Placer - Apparent hang at Placement Phase 9.6.3 Commit Flip-Flops


A case has been seen where a placement appeared to hang at Phase 9.6.3 Commit Flip-Flops.

Investigation revealed that this was not actually a hang.

The design was at the edge of being feasible to fit (80% Flip-Flop utilization and 50K control sets) and the placer was making an exhaustive effort to fit the design.


This will be fixed in a later release so that the placer gives up sooner by default when the design cannot be fit in a reasonable amount of time.

For earlier versions, it is possible to set a parameter to change this behavior:
set_param place.FFSpiralSearchPercentage 0
AR# 56270
Date Created 06/06/2013
Last Updated 11/06/2014
Status Active
Type General Article
  • Virtex-7
  • Kintex-7
  • Artix-7
  • Vivado Design Suite - 2013.1