Can I ask on the EESE about a problem with a Verilog program? I have an apparently simple Verilog module and testbench that is behaving oddly and I cannot understand why. But I don't want to bombard the site with Verilog code if it's off topic.

@JohnRennie Yes It should be on-topic. Just describe the issue you want to solve well, then describe what you expect and what happens instead. And you can dump the code in a blockcode markup, which will display it as a scrollable box

Thanks, I'll post now :-)

@Lundin What I did as a kind of eye opener once when probing a busy board with high frequency stuff on it with the 15 cm ground clip: I took a metal screwdriver and touched it down on a ground pin next to my probe point. Then a tilted the screwdriver such that it made contact with the ground bit of the scope probe. When I was looking at the scope the signal become immediate textbook-level pristine and nice, and when the contact between the screwdriver and probe slipped off, it was trash again

Before this happened, I remember being of the sort of thought: "Ehh these esoteric people.. How bad can it be lol"

@JohnRennie I would say it is much better to post HDL language questions here than on SO (where they are also on-topic) because you are more likely to find a wider audience with the relevant expertise here than on SO.

@tobalt Yeah indeed. I've always been bad at trusting my own measurements with the scope. Then someone with more experience showed me how to reliable measure stuff like voltage regulator output ripple in the mV region. Which has to be measured in AC mode and with good grounding or you'll just pick up noise from the surroundings. For that kind of measurements you easily notice the difference that the grounding does.

Kind of the same story as when I was working together with a fresh out of school engineer on a control system for a wheel loader. He had been trying everything out with his PLC and laptop back home with a bench supply, then arrives on scene with two banana connectors for CANH and CANL but no ground. And then he was stumped why his laptop couldn't connect with the same PLC mounted on the wheel loader.

I hand crafted a ground pin connection between the laptop and the machine et voila, everything suddenly worked. Ground matters!

@tobalt That trick, except with an Exacto knife blade instead of a screwdriver, is described in the Handbook of Black Magic by Johnson and Graham.