They pay money just like any other customer of TSMC. SiFive has a lot of buzz in the industry. I wouldn't be surprised that TSMC wanted to work with them.

But there are other intermediary companies that help startups group multiple chips from multiple companies together into a single mask. This is called a "shuttle" and allows the companies to split the costs of the masks (I've heard up to $30 million for 5nm)

SiFive is probably building about 2,000 of these chips for development boards. They aren't trying to order a hundred million like Nvidia.

Thanks that's very interesting. No intention in any way to belittle SiFive - just puzzled as to how they managed to get onto this process when it's obviously so much in demand. Good for them!

Adding to this, it's in TSMC's interest to have cheaper licenses for high quality processor cores for it's customers, and therefore have strategic reasons to prioritize small runs of RISC-V chips right now.

Pretty classic "commoditize your complement".

Can you list some of these shuttle companies? What are the most popular/reputable ones?

When I have worked at large companies we handled everything ourselves and dealt directly with the fabs.

When I worked at startups and smaller companies we have interacted with:

Global Unichip Corporation (I believe TSMC owns part of the company)

https://www.guc-asic.com/en-global

Open Silicon (they literally merged with SiFive to become OpenFive and made this chip in the article)

https://en.wikipedia.org/wiki/Open-Silicon

Uniquify

https://www.uniquify.com/

Socionext

https://www.socionext.com/en/

There are others but these are the 4 that I have dealt with.

It’s also in TSMC’s marketing interest to product a small number of RISC V parts with their latest process.

Plus it’s probably fun for some of the people there.

For test chips there is something called shuttle.

Other than that, foundries are known to sponsor IP development on their processes.

"The tape out means that the documentation for the chip has been submitted for manufacturing to TSMC, which essentially means that the SoC has been successfully simulated. The silicon is expected to be obtained in Q2 2021."

Would this mean the actual chip delivery may still be delayed?

Chip manufacturing has many steps. For a new leading edge process it may take 3-6 months to get silicon back after submitting the design to a silicon foundry for manufacturing.

For a small volume ‘shuttle’ run hopefully there won’t be delays, but this is not the same as having working chips!

The foundry will do initial checks it is manufacturable at ‘tapeout’ when you submit your design, but you don’t know for sure if your chip works with intended functionality until you get it back! You are relying on lots and lots of simulations up front before your ‘tape-out’.

Sometimes issues are found and a chip requires a re-spin - basically another go with the bugs fixed. You want to do this as few times as possible (ideally right first time) due to cost and time of these iterations.

perhaps paid some money when the process wasn't booked till the end of time