Down Underflow 2026
The FOSSi Foundation is proud to announce the inaugural installment of Down Underflow, a conference dedicated to free and open source silicon to be held in the southern hemisphere over the weekend of Saturday February 28 and Sunday March 1st, 2026 in Sydney, Australia.
Down Underflow is a weekend of presentations and networking for the open source silicon community. Browse through previous installments of FOSSi Foundation events, the shape of which Down Underflow will take, here.
Questions? Ping the organizers via email at downunderflow@fossi-foundation.org.
Register
Down Underflow is free to attend.
If you are able to, please considering assisting with the costs of the event via a "Pay what you want" ticket with an donation. If you are attending Down Underflow on behalf of your company, you are encouraged to donate with a professional ticket. Please choose one option in the checkout process -- you do not need a "Free" ticket in addition to a "Pay what you want" ticket.
Submit a talk
Presentations are submitted through the Eventbrite registration interface.
There are still slots available for regular and lightning talks. Please do err on the side of presenting if you're unsure!
Suitable topics are your work on, with or around open source semiconductor IP, tooling, flows. Even if "all" you've done is successfully (or not!) implement an open source IP or tool, come and share, we'd love to hear your story!
Code of conduct
We expect all Down Underflow participants to adhere to the the FOSSi Foundation code of conduct throughout the event.
Let's talk!
Join the #downunderflow2026:fossi-foundation.org Matrix room to chat with other participants at the conference, share additional information about the talks, about traveling to and from Sydney, and what else comes to your mind!
Venue
Down Underflow 2026 will be held at the offices of Morse Micro in Surry Hills, Sydney, Australia. It is at most a 10 minute walk from Sydney's Central Station.
Details for access to the venue on the day will be emailed to attendees after registering for the event via the link above.
Social event
Saturday evening after the talks at the conference venue have finished we will put on drinks and a dinner for the conference attendees. The venue will be walking distance from the conference site.
Supporters
We thank all our sponsors, exhibitors, and all participants who donated by buying a Pay-what-you-want or Professional Ticket.
Down Underflow is free to attend, but we aim to provide catering and the like during the event. Down Underflow is also a great way to get your company or brand in front of lots of engineers and hackers on the day, and thousands more through recordings of the event.
A variety of sponsorship packages are available for this year's Down Underflow. You'll find all of the details in our sponsorship prospectus.
Please get in touch at downunderflow@fossi-foundation.org if you'd like to explore sponsorship opportunities.
A variety of sponsorship packages are available for this year's Down Underflow.
Down Underflow is organized by volunteers on behalf of the FOSSi Foundation. We are currently looking for more people to help out with arrangements and putting on the event, so please do email us if you would like to volunteer for during the event with setup, AV, or even just local knowledge so we can plan the weekend better.
Schedule
Saturday, Feb 28: Conference, lightning talks, and social event
Schedule to be posted closer to the event.
Sunday, March 1: Unconference and workshops
Still TBD: On Sunday March 1st, should there be sufficient interest, we can make available spaces for folks to meet and discuss projects of interest and even hold workshops.
Ideas for other unconference and workshops?
For example, at previous FOSSi Foundation evnets we've had fantastic sessions on
- cocotb
- Amaranth
- Open Source DFT and in-field debug
- Clash and Haskell
- Surfer
What deep-dives will we have at Down Underflow? It's up to all of us!
Feel free to submit your ideas ahead of Down Underflow or propose them throughout the conference.
Talks
Opening
Welcome to Down Underflow! All you need to know to have a successful conference.
Cocotb: An Introduction and Update
An introduction to and round up of the latest and greatest from the Cocotb project: chip development and verification turbocharger in Python.
OpenROAD in the Classroom: RTL to GDS flow
This talk shares lessons from one of the early structured uses of the OpenROAD RTL-to-GDS flow in an Australian ASIC training course delivered through the Semiconductor Sector Service Bureau (S3B). The course used a fully open-source flow built around Yosys for synthesis, OpenSTA for timing analysis, OpenDP for placement, TritonCTS for clock tree synthesis, and TritonRoute for routing. The presentation focuses on practical flow behaviour, setup and integration challenges, and recurring issues observed in real student designs. It concludes with concrete suggestions on how the community can make OpenROAD easier to use, more reliable, and better suited for teaching and large-scale training.
Lowering barriers to entry to the semiconductor space
An exploration of open source tooling IP and flows which greatly reduce the barrier to entry for semiconductor startups informed by Morse Micro's experience circa 2016 to today.
Slingshot and Slander: Tools for Analysing and Mutating SystemVerilog, Powered by Slang
SystemVerilog is a challenging language to parse. Thanks to Mike Popoloski's Slang SV frontend, state-of-the-art FOSS parsing of complex SystemVerilog has been achievable. Using Slang, I present two tools: Slingshot and Slander. Slingshot is a SystemVerilog Language Server Protocol (LSP) with a focus on accurate and fast completion, whereas Slander is a tool for minimising and mutating SV for the purposes of fuzzing.