Non-rectangular Blocks

If you have non-rectangular blocks, some of the area might be available for standard cell placement.

For an optimal design, follow these guidelines:

• In the LEF file use the overlap layer to describe the area that is not available for placement of other cells.
• Otherwise, by default, the bounding box of the boundary or the SIZE statement in the LEF file is used for the shape of the cell.
• Use Abstract Generator to translate the boundary layer into the LEF overlap layer.

Define an blockage on the OVERLAP layer in the block (mega cell) over the areas that are not available for cell placement.

Related Topics

Guidelines for Defining Blockages in a Cell Library

Guidelines for Setting Cell Porosity and High Density in a Cell Library