[libre-riscv-dev] daily kan-ban 07may2020 update

Luke Kenneth Casson Leighton lkcl at lkcl.net
Fri May 8 10:08:02 BST 2020

On Fri, May 8, 2020 at 9:41 AM Staf Verhaegen <staf at fibraservi.eu> wrote:

> As a backup plan I had in mind to tape-out some other CPU like a SwerV RISC-V core from Western Digital.

which would test the Cell Library (and the Libre development workflow)
very well.  except because it would come from the NLNet budget, it
would remove the opportunity for us to have an NLNet-funded tape-out.

> Alternatively some of the budget could be used so I can look into multi-port RAMs and register files; maybe I can have a closer look at a PLL also.

a Professor at LIP6.fr is happy to design one.

> These could first be tested on 0.35um which costs a lot less (ca. $5000 vs. ca $20000).

if we drop the slot, we should talk that through with NLNet.  they're
critical components so would be good to have.  also that clock-gating

> There is question about funding. It takes about 3 months after tape-out to get the chips and then the debugging of the chip can only begin which typically also takes a lot of time. So if we delay the tape-out the completion of the testing of the chip will miss the deadline for the current NLNet funding. I am currently supposed to do the testing of the chip but I won't start that if I don't know if I can get the funding for it.

ok so what you're saying is: if we try to do a later date, then we're
outside of the window for not just NLNet funding proposals, but
funding from NLNet *at all*, due to the EU Horizon 2020 conditions
that NLNet-funded projects be 100% completed Q3/4 of 2021.

> 0.18um TSMC MPW runs are done at least once a month. You can find the schedule online: https://europractice-ic.com/wp-content/uploads/2020/05/General-MPW-EUROPRACTICE-200505-v8.pdf

so everyone is aware: these general 180nm MPW runs are not EUR 600 /
sq.mm (the subsidised cost via Staf).  they're 2-3x that level: around
EUR 1100 to 1500

Yehowshua wrote:

> And worst case scenario, I can acquire the needed funds for testing the chip from alternative funding sources no problem.

this is good - it would however not be at the EUR 600 / sq.mm level,
it would be at double that, and also likely need Staf's paid-for
assistance (if you're up for that, Staf?) to act as a firebreak for
the NDAs.


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