OpenROAD placement experiments

Placement visualisation and image-derived blockage experiments in OpenROAD.

This repository contains my modifications to OpenROAD’s global placer for recording placement evolution and experimenting with image-derived blockages. It extends the OpenROAD/RePlAce implementation.

OpenROAD displaying an arithmetic circuit placement.

Watch placement evolve

With the modified build and OpenROAD-flow-scripts, a placement run can open the GUI:

make DESIGN_CONFIG=./designs/asap7/aes/config.mk OR_ARGS=-gui place

The README enables placement visualisation with this Tcl command before global placement:

global_placement_debug -pause 1 -update 1 -initial -draw_bins

Image-derived blockages

The image conversion script treats black pixels as blocked regions and white pixels as available placement area. It produces Tcl constraints scaled and centred on the core.

The script’s image and geometry settings currently need editing in the source; they are not implemented as command-line options. These experiments support placement visualisation and shaped-layout studies, rather than defining a separately validated placement algorithm.