SpinalHDL VS satcat5

I'd love to see textual preprocessors kinda banned. Or at least done upstream and outside of the language. You can't both be and also have a textual preprocessor defined internally. It doesn't work.

I really like what Zig and C++ are doing with `const`.

https://ikrima.dev/dev-notes/zig/zig-metaprogramming/

Have you looked at Spinal?

https://github.com/SpinalHDL/SpinalHDL

https://spinalhdl.github.io/SpinalDoc-RTD/master/index.html

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

I have just found that SpinalHDL also implemented two halves of the fully registered buffer in Stream.scala.

Don’t forget SpinalHDL that was forked off of Chisel 2 I believe. These DSLs really leveraged the software features of Scala to help build generalised/modular systems. And are generally a quality of life improvement in the language features available.

A lot of reuse from other FOSH projects, including Litex, SpinalHDL, betrusted & u/alexforencich verilog-wishbone. Thanks to all of them :-)

You could try to implement a PCIe root complex for FOSS SoCs, connecting to e.g. Wishbone as the main bus. There's already some DDR3 controller (or this one) and USB Host controller out there, and even device-side PCIe, but no FOSS host-side PCIe that I know of. Probably quite a difficult job though, even sticking to the lower-speed PCIe 1.

I needed 128-bit and 256-bit integers on an embedded project recently.

In short, it was for fixed-point digital signal processing. The raw input and output samples were int64_t. We needed to add, subtract, multiply, and accumulate these to do filtering and linear regression with no loss of precision.

Conventional bigintegers weren't an option because the target application doesn't allow heap allocation. So we rolled our own [1] stack-allocated, fixed-width big integer class.

[1] https://github.com/the-aerospace-corporation/satcat5/blob/ma...

And here's an open-source implementation I wrote a few years back. You can skip the part at the end that handles variable-length trailing bytes, since you have a fixed-width input.

My SatCat5 project also has a few options. Anything under src/vhdl/common/cfgbus_* can be connected to AXI or Wishbone with a simple adapter.

For an all-digital solution, here's an NCO that generates an arbitrary-frequency square wave from a numeric counter.