>If you check the twitter thread, he didn't create a CPU, or anything close to one. As far as I can tell, he just took some circuits that others created (e.g., debouncer, pwm) and hooked them up to create a 3 channel LED controller that can output a pulse signal. That's it. He did go through the rest of the flow (synthesis, STA, P&R, etc.) but it seems to be the core only, there's no pads or anything to connect the chip to a package, it's just the core logic.

His complaints about the inability to find any details on GPU architectures strikes me as weird because there's a wealth of information about it out there, especially if (as he clarifies in later posts in his thread) you're ignoring the fixed function and graphics aspects of a GPU and just making it GPGPU, at which point the architecture is largely "high-way SMT in-order CPU architecture with SIMD execution units"--nothing out of the ordinary in any advanced computer architecture course.