ORFS → OpenLithoHub Integration

This guide walks through the end-to-end pipeline from an OpenROAD-flow-scripts (ORFS) routed design to a lithographic manufacturability report.

Prerequisites

• ORFS cloned and built: git clone https://github.com/The-OpenROAD-Project/OpenROAD-flow-scripts
• OpenLithoHub installed: pip install -e .
• KLayout installed (for GDS rasterization): pip install klayout

Quick Start

1. Produce a routed GDS with ORFS

cd OpenROAD-flow-scripts
make DESIGN_CONFIG=designs/asap7/mock-alu/config.mk
# Output: results/asap7/mock-alu/base/6_final.gds

2. Run the flow pipeline

openlithohub flow run results/asap7/mock-alu/base/6_final.gds \
    --pdk orfs_asap7 \
    --layer metal1 \
    --tile-nm 2000 \
    --node 45nm \
    --output report.json

3. Using a custom PDK layermap

Create a JSON file with your PDK's layer numbers:

{
    "metal1": [20, 0],
    "metal2": [30, 0],
    "via1": [21, 0]
}

openlithohub flow run design.gds --pdk my_custom_layermap.json --layer metal1

Supported PDKs

PDK	Key	metal1	metal2	via1
ASAP7 (cell lib)	asap7	(10, 0)	(11, 0)	(12, 0)
FreePDK45	freepdk45	(11, 0)	(13, 0)	(12, 0)
ORFS-routed ASAP7	orfs_asap7	(20, 0)	(30, 0)	(21, 0)
SkyWater 130nm	sky130	(67, 20)	(69, 20)	(68, 44)

CLI Reference

openlithohub flow run [OPTIONS] INPUT_PATH

Arguments:
  INPUT_PATH  GDS/OAS/DEF file or ORFS results directory

Options:
  --pdk TEXT              PDK layer mapping name or path to custom JSON
  --layer TEXT            Layer name from the PDK layermap [default: metal1]
  --pixel-nm FLOAT        Pixel size in nm [default: 1.0]
  --tile-nm FLOAT         Tile edge length in nm [default: 2000.0]
  --node TEXT             Process node for litho params [default: 45nm]
  --resist-diffusion-nm   Acid diffusion length in nm [default: 0.0]
  --quencher FLOAT        Quencher concentration [default: 0.0]
  --drc / --no-drc        Run DRC compliance [default: on]
  --mrc / --no-mrc        Run MRC compliance [default: on]
  --output PATH           Save JSON report to file
  --deterministic         Force bit-reproducible backends

Architecture

The flow command chains these existing OpenLithoHub components:

1. Layer resolution — _layers.py → JSON layermap → (layer, datatype) tuple
2. GDS rasterization — data/io.py via KLayout
3. Tiling — data/orfs.py tile_design_tensor() at 2µm/5µm windows
4. Hopkins forward — simulators/hopkins_sim.py with SOCS kernels
5. Resist modeling — optional acid diffusion via --resist-diffusion-nm
6. Metrics — EPE, PV Band, DRC, MRC per tile
7. Aggregation — mean across tiles → JSON report

License Compliance

The flow CLI only reads user-provided files. It never downloads, bundles, or redistributes PDK data. Users must obtain ORFS and PDK artifacts independently and accept the relevant licenses (ASAP7 BSD-3-Clause, sky130 Apache-2.0, etc.).