RISC-V 3D GPU / CPU / VPU

Note: this is a hybrid CPU, VPU and GPU. It is not, as many news articles are implying, a "dedicated exclusive GPU". The option exists to create a stand-alone GPU product (contact us if this is a product that you want). Our primary goal is to design a complete all-in-one processor (System-on-a-Chip) that happens to include a libre-licensed VPU and GPU.

We seek investors, sponsors, engineers and potential customers, who are interested, as a first product, in the creation and use of an entirely libre low-power mobile class system-on-a-chip. Comparative benchmark performance, pincount and price is the Allwinner A64, except that the power budget target is 2.5 watts in a 16x16mm 320 to 360 pin 0.8mm FBGA package. Instead of single-issue higher clock rate, the design is multi-issue, aiming for around 800mhz.

The lower pincount, lower power, and higher BGA pitch is all to reduce the cost of product development when it comes to PCB design and layout:

  • Above 4 watts requires metal packages, greater attention to thermal management in the PCB design and layout, and much pricier PMICs.
  • 0.6mm pitch BGA and below requires much more expensive PCB manufacturing equipment and more costly PCBA techniques.
  • Above 600 pins begins to reduce production yields as well as increase the cost of testing and packaging.

We can look at larger higher-power ASICs either later or, if funding is made available, immediately.

Recent applications to NLNet (Oct 2019) are for a test chip in 180nm, 64 bit, single core dual issue, around 300 to 350mhz. This will provide the confidence to go to higher geometries, as well as be a commercially viable embedded product in its own right.

See:

Progress:

  • Jul 2019: Sponsorship from Purism received. IEEE754 FP Mul, Add, DIV, FCLASS and FCVT pipelines completed.
  • Jun 2019: IEEE754 FP Mul, Add, and FSM "DIV" completed.
  • May 2019: 6600-style scoreboard started
  • Apr 2019: NLnet funding approved by independent review committee
  • Mar 2019: NLnet funding application first and second phase passed
  • Mar 2019: First successful nmigen pipeline milestone achieved with IEEE754 FADD
  • Feb 2019: Conversion of John Dawson's IEEE754 FPU to nmigen started
  • Jan 2019: Second version Simple-V preliminary proposal (suited to LLVM)
  • 2017 - Nov 2018: Simple-V specification preliminary draft completed
  • Aug 2018 - Nov 2018: spike-sv implementation of draft spec completed
  • Aug 2018: Kazan Vulkan Driver initiated
  • Sep 2018: mailing list established
  • Sep 2018: Crowdsupply pre-launch page up (for updates)
  • Dec 2018: preliminary floorplan and architecture designed (comp.arch)

News Articles

Information Resources and Tutorials

Analog Simulation

Evaluations

*openpower