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Is that what “high speed digital design” is? Like the stuff that Dr Howard Johnson teaches? Or is that not the same scope or maybe still something entirely different?


"High Speed Digital Design" generally refers to PCB level design. The Black Magic books are pretty old, covering ancient stuff like DIP packages on manhattan-routed boards. These days the keyword is SI/PI (Signal Integrity, Power Integrity).


I'm not familiar with that book but I just looked at some previews and it seems to be exactly what I'm getting at. I built a large number of radio transmitters in my younger years (long story) in the 100 MHz range, that was all analog so I had a pretty good idea of what it was like to design high frequency stuff, or so I thought. Then I tried to do a bunch of digital circuits at 1/10th that frequency and even after only a hand full of components in a circuit you'd get the weirdest instabilities. From there to the point that you can reliably design digital circuitry is a fascinating journey and gives you infinite respect for what goes on under the hood of a modern day computer.


Yes, and a reason for it subtitle "A Handbook of Black Magic" :). In the olden days EEs would more or less guess by intuition and heavy sprinkling or randomly placed pullups/pulldowns/capacitors to force designs into stable working order.

https://hackaday.com/2019/01/24/video-putting-high-speed-pcb...

Dont remember the exact video, but Bill Herd mentioned many times about on site last minute fab fixes involving prodding the product on a hunch of where the problem might be.

Today you can simulate and measure pretty much everything, plus automated design rule tools will warn you of potential problems beforehand.




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