amaranth VS myhdl

He probably meant Amaranth.

As an aside, the latest and active development of nMigen has been rebranded a few months ago to Amaranth and can be found here: https://github.com/amaranth-lang/amaranth . In case people googled nMigen and came to the repository that hasn't been updated in two years.

Hmm. A followup question: are there any cheats/hacks that would make it possible (if painful) to for example explore the world of USB3, PCIe, or Linux on low-end-ish ARM (eg https://www.thirtythreeforty.net/posts/2019/12/my-business-c..., based on the 533MHz https://linux-sunxi.org/F1C100s), without needing to buy equipment in the mid-4-figure/low-5-figure range, if I were able to substitute a statistically larger-than-average amount of free time (and discipline)?

For example, I learned about https://github.com/GlasgowEmbedded/glasgow recently, a bit of a niche kitchen sink that uses https://github.com/nmigen/nmigen/ to lower a domain-specific subset of Python 3 (https://nmigen.info/nmigen/latest/lang.html) into Verilog which then runs on the Glasgow board's iCE40HX8K. The project basically makes it easier to use cheap FPGAs for rapid iteration. (The README makes a point that the synthesis is sufficiently fast that caching isn't needed.)

In certain extremely specific situations where circumstances align perfectly (caveat emptor), devices like this can sometimes present a temporary escape to the inevitable process of acquiring one's first second-hand high-end oscilloscope (fingers-crossed the expensive bits still have a few years left in them). To some extent they may also commoditize the exploration of very high-speed interfaces, which are rapidly becoming a commonplace principal of computers (eg, having 10Gbps everywhere when USB3.1 hits market saturation will be interesting) faster than test and analysis kit can keep up (eg to do proper hardware security analysis work). The Glasgow is perhaps not quite an answer to that entire statement, but maybe represents beginning steps in that sort of direction.

So, to reiterate - it's probably an unhelpfully broad question, and I'm still learning about the field so haven't quite got the preciseness I want yet, but I'm curious what gadgetry, techniques, etc would perhaps allow someone to "hack it" and dive into this stuff on a shoestring budget? :)

Worth knowing that are two "nmigen"s nowadays - the one originated in M-Labs and one under a project also called nmigen:

https://github.com/nmigen/nmigen

It's a fork, made for reasons, but more actively developed. whitequark (long time author/contributor) works on this fork, and no longer the M-Labs version.

Sounds like nmigen might be a good open source successor to the project that you describe: https://github.com/nmigen/nmigen

Thank you for tackling this critical problem for logic designiners. I think the tools available are much too old for fast paced workflows.

From my experience attempting to get a similar workflow down for my company:

I tried to use verilator a while back but ultimately I couldn't because it didn't have same constraints in the verilog language features that I was going to use in production. It doesn't even matter who was missing a feature, verilator or the proprietary tool, it was just about getting them to be same that caused the cognitive dissonance that I didn't want to deal with.

I ultimately decided to move away from verilator and use the clunky proprietary tools since it was what would be used in production. Getting "verilator compatibility" seemed like a "nice to have".

Second, the a winning local-first framework of verilator wasn't really established. You show in your example running a test from the yaml file using what looks like a bash script. Even as an experienced programmer who knows bash and sh well, I still find it very hard to write complex thoughts in it. The last high level attempt I found to bridge this gap is likely https://www.myhdl.org/ I don't know them personally, but it seemed like they had some very good thoughts on what makes writing good hardware level tests good. I think it would be worth reaching out to them if you haven't already.

The one thing that even more critical was a way to run our tests locally. The 10-20 seconds it takes to start a docker image (best case) in the cloud is really frustrating when you are "so close to finding a bug" and you "just want to see if this one line change is going to fix it". Once we got our whole pipeline going, it would take 1-6 minutes to "start a run" since it often had to rebuild previous steps that cache large parts of the design.

So I think you will want to see how you can help bring people's "local's first" workflows slowly into the cloud. Some tools (or just tutorials) that help you take a failing test, and run it locally and on the cloud will be really good especially as you get people to transition!

Also PyMTL, PyRTL, and MyHDL.

MyHDL

Any hardware designers here who use Python for designing hardware? There are a bunch of libraries that all seem promising MyHDL, PyRTL, PyVerilog, PyLog, PyMTL3, ... All seem to work roughly the same. Write code in Python and transpile it to VHDL/Verilog. Which of these are popular and well-maintained? MyHDL looks good but it's last release was 0.10 in 2018 and for hardware design you don't want to rely on 0.x software. Anything like Chisel for Python.

It is : https://www.myhdl.org/

Personally I have fond memories of MyHDL [0], which may be seen as another "code-to-silicon" converter (or at least as the first step of a code-to-silicon workflow). I used it only briefly, and on a school project that had surprisingly little to do with actual hardware design [1], but it really felt "Pythonic" in the best possible way.

[0]: https://www.myhdl.org/

[1]: https://github.com/lou1306/gssi/tree/master/2pc