[alain94040]

HDLs such as Verilog are fine when you keep in mind what the D stands for. They are not programming languages. They are hardware description languages. Languages used to describe hardware. In order to describe hardware, you need to picture it in your head (muxes, flops, etc.). Once you do, writing the HDL that describes that hardware is reasonably easy.

What doesn't work is using an HDL to write as if it were software. It's just not.

[0] I'm talking about the RTL subset obviously

[aseipp]

Sure, I don't think anything I said disagrees with that. This conceptual shift in "declarative description" of the HW is a big difference in moving from software to hardware design, and no language can remove that difference. It doesn't matter if you're using MyHDL or Haskell to do it! It just so happens Haskell is a pretty declarative language, so it maps onto the idea well.

But it's not just about that... Frankly, most HDLs have absolutely poor abstraction capabilities, and are quite verbose. Sure, it isn't a software language, but that's a bit aside from the point. I can't even do things like write or use higher order functions, and most HDLs don't have very cheap things like data types to help enforce correctness (VHDL is more typed, but also pretty verbose) -- even when I reasonably understand the compilation model and how the resulting design will look, and know it's all synthesizable!

On top of that, simply due to language familiarity, it's simply much easier for me to structure hardware descriptions in terms of things like Haskell concepts, than directly in Verilog. It wouldn't be impossible for me to do it in Verilog, though -- I'm just more familiar with other things!

At some level this is a bit of laziness, but at another, it's a bit of "the devil you know". I do know enough Verilog to get by of course, and do make sure the output isn't completely insane. And more advanced designs will certainly require me going deeper into these realms where necessary.

I've recently been writing a tiny 16-bit processor with Haskell, and this kind of abstraction capability has been hugely important for me in motivation, because it's simply much easier for me to remember, describe and reason about at that level. It's simply much easier for me to think about my 2-port read, 1-port write register file, mirrored across two BRAMs, when it looks as nice and simple as this: https://gist.github.com/thoughtpolice/99202729866a865806fd6d..., and that code turns into the kind of Verilog you'd expect to write by hand, for the synthesis tool to infer the BRAMs automatically (you can, of course, also use the direct cell library primitive).

That said -- HDL choice is really only one part of the overall process... I've still got to have post-synthesis and post-PNR simulation test benches, actual synthesizable test benches to image to the board, etc... Lots of things to do. I think it's an important choice (BlueSpec is another example here, which most people I've known to use it having positive praise), but only one piece of the overall process, and grasping the whole process is still something I'm grappling with.