TT GDS Macro BlackBox Testing

A repository for testing blackbox GDS art integration into TT tiles.

Note: Work In Progress

---

Requirements:

• GDSPY: apt install python3-gdspy
  • required to add boundary layers to GDS files and to remove output driver cells:
• rsvg-convert: For SVG based input images
• magic if your design is a pure art design, to manually add the VPWR, VGND nets and remove the output drivers.

Getting Started

For Digital and Mixed Signal Designs:

1. First, git submodule update --init.
2. Place your magic art designs in mag/ or gds/
3. run make preproc <name_of_macro_in_gds_or_mag>
   • This will produce GDS/LEF outputs used during a Openlane2 custom flow.
   • Additionally, a PN boundary layer will be added to any converted GDS or converted MAG during the preproc phase.
4. Make a copy of src/ttlogo_config.json as src/<my_macro_name>_config.json
   • Edit the VERILOG_DEFINES and MACROS inside the config options to specify which macro you would like to place.
   • If you are using this to add a logo to an existing project, you need to delete the flow in the config, and use the normal classic flow.
5. Run make tt_harden_top <my_macro_name>.
   • If your design in purely art, and has no logic, please do: PURE_ART=1 make tt_harden_top <my_macro_name>
   • If you need to override the top module name set TOP_NAME= as well.
6. The final designs are now made available in {gds,mag,lef}/final.

---

For analog designs:

For SVG macro art:

1. Place your target macro images inside img/
2. Convert SVG to PNG: rsvg-convert img/my_image.svg -o img/my_image.png
3. Convert the image to GDS with PN boundary:
   • ./script/make_gds.py -i img/my_image.png -c my_image -o gds/my_image.gds
4. Manually import the resulting instance into your Magic design or other analog program.

TODO: Write a magic placement script for all of this.

---

FAQ

Q: Why can't we support the analog flow with macros?

A: We can, it just makes no sense to and is needlessly complicated. Analog designs for TT aren't being used with openlane, so we should stick with analog methods as appropriate.

Things to be done (TODO)

• (Fix the flow properly stream out the GDS, GDS -> isn't including PR boundary)
• (Make sure we support input mags that have power nets that we will eventually ignore)
• (The PDN config is basically a no-op. we can interleave configs for mags that needs a POWER net)
• (Standardize and document minimal flow required to macro place without detailed or global routing)
• (Alow the usage of multiple macros in the blackbox using a generate verilog statement)
• (Write a analog magic art macro placement script)