Question Your own 130nm custom silicon if you dare

Google SkyWater OpenPDK is rather old at this point:

I'm sure that I saw a photo of wafers related to Zero to ASIC and eFabless: https://hackaday.com/2023/02/14/sup...iny-tapeout-brings-chip-design-to-the-masses/

FPGA on a custom PCB should be far more accessible and commerciable viable than these, but I understand the novelty value of custom silicon.

The ideal node imho is going to be this: https://github.com/google/sky90fd-pdk , non-FOSS MPW #10 for RH90 GDS Submission---Cutoff => 2/1/24---2/15/24
Overall lowest leakage and dynamic power. SkyWater is doing the 200mm wafers, while GlobalFoundries side does the 300mm wafers. With MIT developing the (045SOI) 45-nm node variant. I wonder if we get to see a sky45fd-pdk as well.

Indiana target(shuffled into Minnesota refunding) is interesting for SkyWater. sky22fd-pdk eventually? "Additionally, as a part of the MOU, GF and SkyWater will align technology roadmaps and leverage unique and complementary capabilities for development and high-volume production path to market for advanced computing, artificial intelligence and related technologies." R&D at Skywater -> Low volume trial at Skywater/200mm -> High volume production at GlobalFoundries/300mm.

Through efabless we can see;
16-bit, Piotr Wegrzyn's ppcpu(MPW-7), ppcpu2(MPW-8) for Skywater 130nm: https://www.piotro.eu/#projects
32-bit, Mathis Salmen's SoomRV for both MPW-7 and MPW-8 also Skywater 130nm: https://github.com/mathis-s/SoomRV
64-bit, Keith Dsouza doing CVA6 for CI 2404 also Skywater 130nm: https://github.com/openhwgroup/cva6

However, the importance of 90nm is huge since it is the era of 90nm CBE at 235 mm2.
All PS2 MMOs and most-early PC MMOs should be able to run on a more efficient heterogeneous multi-processing capable-device. There is even an open-source Vulkan driver somewhere for RVV.
A MMO that is not tab target, for example:
CPU: Coppermine 1 GHz(min) to Willamette 1.5 GHz(rec)
GPU: Any 32 MB GPU(min) to Any 128MB GPU(rec)
Ideally replacing the PPE with more compact GS464V-like/Godson-2E-Loongson 2F-like, RISC-V orientated cores.
While using SiByte/Broadcom SB-1-like and/or Raza XLR, etc for the SPEs. Bunch of designs to get RISC-V'd. To do the CBE/POD shuffle.
PPE-90=26.86 mm2 and SPE-90=14.76 mm2, only need to beat these super-large cores.

So, I am expecting more stuff going the route of the Playdate (STM32F746 (90nm) + ESP32-D0WDQ6 (40nm)). The FOSS SkyWater/Google/GlobalFoundries stuff is important for improving hobby gaming/hobby Games as a Service.

If anyone is wondering when 90nm FDSOI is happening at Skywater.
"we continue to make progress on the productization and qualification of SkyWater’s 90nm RadHard platform to prepare for the planned production ramp in 2025." - June 2023