Fixed and Unfixed Cells - 2025.1 English - UG906

Vivado Design Suite User Guide: Design Analysis and Closure Techniques (UG906)
Document ID
UG906
Release Date
2025-05-29
Version
2025.1 English

Fixed and Unfixed apply to placed cells. They describe the way in which the Vivado tools view placed cells in the design.

For more information about Fixed and Unfixed Cells, refer 'Modifying Placement' in the Vivado Design Suite User Guide: Implementation (UG904).

Recommended: After the I/Os are placed, use a hierarchical Pblock floorplan as a starting point for user-controlled placement. Hand placing logic should be used when Pblocks have been found not to work.