KEY Placement inputs: a completed floorplan, the SDC/MMMC, and design targets like max_trans and max_area.

Results Produced by Placement

• A legalised cell placement.
• A congestion picture.
• A design density picture.

KEY Placement produces legalised cell placement plus congestion and density results.

Constraints Used During Placement

• Placement blockages - partial, soft and hard.
• Bounds - guide, region and fence.
• Magnet placement.
• Relative placement.
• Keepout margin and cell padding.

KEY Placement constraints include blockages, bounds, magnet and relative placement, and keepout/padding.

Checks Performed at Placement

• Legality of the cell placement and the resulting timing.
• Module placement - whether each module is kept together.
• Path-by-path congestion review.
• Congestion, defined as required tracks divided by available tracks.
• Required tracks can be reduced by lowering cell density and pin density and by avoiding criss-cross signal routing caused by wrongly placed cells on a path.
• Cell density is managed with soft, partial and hard blockages and with guide, region, fence and keepout-margin constraints.
• Pin density is also checked - case 1: pin density high but cell density acceptable; case 2: pin density acceptable but cell density high; case 3: both pin and cell density high.