Do you have a discussion list?

Yes, you can now subscribe to lowrisc-dev and view archives here.

Are you hiring?

Yes! See our jobs page.

Are contract or remote working arrangements on offer?

We are not currently looking for contract or remote workers, but may in the future. If we do, we’ll advertise via this website and the announcement list.

What are the goals of the project?

  • To create a fully open SoC and low-cost development board and to support the open-source hardware community. This will involve volume silicon manufacture.
  • To explore and promote novel hardware security features
  • To make it simple for existing companies and especially semiconductor startups to create derivative designs, e.g. by sharing scripts, tools, source and our experience
  • To create a benchmark design to aid academic research

When can I buy a lowRISC SoC?

As with most tech projects, the most accurate answer is “When it’s ready”.

Why RISC-V and not OpenRISC/SPARCv8/MIPS/…?

We considered two aspects when surveying the potentially instruction set architectures (ISAs), firstly the features of the ISA itself and secondly the existence of high performance designs. RISC-V is a 64-bit, contemporary clean-sheet design. Implementations exist in an open-source HDL (Chisel) and multiple high performance test chips have been produced, at 45 and 28nm. When performing this survey, the requirement that the ISA be freely implementable rules out most ISAs currently used by the industry. We did consider using older versions of commercial ISAs (i.e. versions where all relevant patents would have expired), but this raises the issue of how to go about bringing them up to date. To avoid legal uncertainty, we would have to make arbitrarily different choices to the original vendor, which means compatibility would be lost.

What features and peripherals will the SoC have?

We’ll distribute draft specifications as soon as is reasonable. The plan is to share as much as possible as early as possible.

How will your designs be licensed?

A permissive open-source license.

How is this different to Raspberry Pi?

Our goals and focus are quite different. The Raspberry Pi exists to improve computer science education worldwide. A fully open-source SoC is not necessary to reach this goal, or even a pragmatic way of achieving it given the timescales involved. While it is an ultimate goal to support all the features of a modern commercial SoC, it will require a number of iterations of the design to achieve this. For example, early versions of our SoC will not include a GPU.

What is your relationship to Raspberry Pi?

We know the team well but this is a completely independent project. Robert co-founded Raspberry Pi, while Alex is a contributor since the very early days of the project.

What level of performance will it have?

To run Linux “well”. The clock rate achieved will depend on the technology node and particular process selected. As a rough guide we would expect ~0.5-1GHz at 40nm and ~1.0-1.5GHz at 28nm.

Is volume fabrication feasible?

Yes. There are a number of routes open to us. Early production runs are likely to be done in batches of ~25 wafers. This would yield around 100-200K good chips per batch. We expect to produce packaged chips for less than $10 each.

How can I contribute?

We really appreciate contributions of code or ideas to our software and hardware development efforts. Take a look at our mailing list and source repos. See our community page for pointers to our code repositories and development mailing lists. If you’re looking for ideas on where to start, perhaps introduce yourself on the mailing list detailing your interests.