Welcome to the OPC series of CPUs, where everything fits on one page - one page each for specification, emulation, HDL. For details see the OPC Project web pages.
Computer architecture, Verilog code to implement the design, simulation and testing of the design, writing an assembler and assembly to test the system. All within my favorite kind of constraint - fitting each component on one page.
They’re not particularly useful machines, but they do de-mystify the bridge from electrical engineering to software engineering.
When I was an intern at Texas Instruments, the tools for this were enormously complex, slow, and expensive. Whole clusters of Sun machines set aside for simulating the upcoming designs and verifying they did the right thing in software. Not to mention the tremendous effort of verifying the design that was coded was possible to build in the company’s chip fabrication plants and processes.
That this depth of tooling is now available to hobbyists would have blown me away in 2002.