shecc VS chipyard

Yes, consider the case of shecc. It requires just a handful of C code lines to interpret directives set in the C preprocessor. Unlike relying on existing tools like cpp, as, or ld, shecc stands alone as a minimalist cross-compiler. This design could be particularly beneficial for students delving into the study of compiler construction. See https://github.com/sysprog21/shecc/blob/master/src/lexer.c#L...

I'm looking at this one for a CPU design I've been working on. :)

https://github.com/jserv/shecc

It's probably true that Chisel isn't right for industry -- Google tried it too for the TPU project and eventually went back to Verilog. That said, I think it's main win is that it is great from a research / open-source perspective.

Taking advantage of the functional nature of Chisel enables a set of generators called Chipyard [0] for things like cores, networking peripherals, neural network accelerators, etc. If you're focusing on exploring the design space of one particular accelerator and don't care too much about the rest of the chip, you can get a customized version of the RTL for the rest of your chip with ease. All the research projects in the lab benefit from code changes to the generators.

Chisel even enables undergraduate students (like me!) to tape out a chip on a modern-ish process node in just a semester, letting Chisel significantly reduce the amount of RTL we have to write. Most of the remaining time is spent working on the actual physical design process.

[0]: https://github.com/ucb-bar/chipyard

[1]: https://classes.berkeley.edu/content/2023-Spring-ELENG-194-0...

The repo in question is chipyard: https://github.com/ucb-bar/chipyard

Many companies do just write entire modern SoCs in straight Verilog (maybe with some autogenerated Verilog hacked in there) with no other major organization tools aside from the typical project management stuff. The load-store unit of a modern CPU alone easily exceeds 10k lines of Verilog. It's a similar thing as people who work with kernels—after all, the page table management code in a modern operating system like Linux is absolutely monstrous but still people are able to understand it well enough to be able to make the changes they need and get out.

If you are interested in other languages which hope to make this sort of stuff easier, I'd recommend taking a look at design productivity languages like Chisel and it's associated Chipyard [1], SpinalHDL [2], and Bluespec [3]. Each of these are meant to make defining extremely complex hardware more manageable for humans and there's a lot of interesting work going on right now with each of them.

[1] https://github.com/ucb-bar/chipyard

[2] https://github.com/SpinalHDL/SpinalHDL

[3] https://github.com/B-Lang-org/bsc