20 Jun
2016
20 Jun
'16
8:36 p.m.
On Mon, 20 Jun 2016, Ian Finder wrote:
The hardest part of the process is distilling the
functional
specification of the part you are trying to replace. This is the heart
of the topic.
Hmm, okay so that's pretty much what I expected. They start with what that
particular chip or ROM etc.. _does_ then they re-implement as a process of
discovery. Does that sound accurate?
There is no one approach, it is more art than science.
That's also what I expected. I guess as I was reading through other
material, I got the impression that it might be more deterministic, but my
gut feeling was right, I think. Nothing is ever *that* easy.
For going from a functional specification to a
synthesizable model, this
is simply writing HDL. I suggest this book, which covers the basics of
this process.
https://www.amazon.com/Verilog-Digital-System-Design-Verification/dp/007144…
Whoa. That's a pricey sucker. I'm probably not going to be able to make
use of Verilog for a little bit yet. I'm still designing all my little
"homework assignment" type projects on paper or using a tool I found in
pkgsrc called "The Eagle Layout Editor." It's got some nice features (at
least for me so far). I'll probably go with the Wirth book since it's a
bit cheaper, but I still appreciate your suggestion.
If you have no 100-level understanding of digital
logic, start here:
https://www.amazon.com/Contemporary-Logic-Design-Randy-Katz/dp/0201308576
I have about a 100-level understanding, now. I took a digital logic class
in college and I still have my book. It's "Fundamentals of Digital Design"
I believe (or something very close to that). It was a while back, though.
I understand boolean logic, changing base for numbering systems, etc..
However, I have a breathtaking lack of experience in applying that stuff
to "real" digital logic. I'm just using online tutorials and guides for
the moment, but the main one I focus on is this one:
http://www.learningelectronics.net/vol_4/index.html
So far, it's been great. I'm just finishing up some of the analog stuff on
that same site, and I've greedily skipped ahead a bit to digital. However,
I'm just now getting to TTLs and gates. I have to actually write out
examples or test things physically to really "get it". However, I'm just
plodding along. I have a nice little mess happening on my workbench in the
garage. I'm about to move on past just using simple capacitors, resistors,
and diodes to using some ICs. It's a little intimidating, actually. I
thought I could get to the point I'm at now in about two weeks. It
actually took about five or six weeks (just for an analog refresher). I'm
still a bit shaky on some of that stuff, too. It's hard to test/see
everything. So, some things I just read about, shrug, and keep going.
-Swift