How do they make Verilog code for unknown ICs?

[Toby Thain]

On 2016-06-20 3:35 PM, Swift Griggs wrote:
>
> In my recent studies of electronics (I'm a noob for all practical
> purposes) I keep seeing folks refer to Verilog almost as a verb. I read
> about it in Wikipedia and it sounds pretty interesting. It's basically
> described as a coding scheme for electronics, similar to programming but
> with extras like signal strength and propagation included. Hey, cool!
>
> Why are folks referring to "Verilogging" and "doing a verilog" on older
> chips. Is there some way you can stuff an IC into a socket or alligator
> clip a bunch of tiny leads onto it and then "map" it somehow into Verilog?
> Is that what folks who write emulators do?

They firstly go by documentation, and if that fails, reverse engineer, 
painfully. This is why preserving, archiving, publishing documentation 
is so incredibly important!

 > Ie.. they exhaustively dump
> Verilog code for all the chips then figure out how to implement that in

You can't in general get Verilog *out* of a chip. It goes the other way. 
You can compile Verilog into gates and netlists etc.

> some computer programming language like C ? What do folks do for ROM chips
> and PLCs? I'd think they must dump the code and disassemble it. No?

Yes, they do that where possible.

>
> I'm just curious and this is a tough question to answer with Google since
> I'm pretty clueless and don't know the right words to search for. I notice

You can google "EDA tools". You can also grab toolchains from major 
vendors like Altera and play with Verilog/VHDL and simulate the results, 
too.

> people talk about correcting their Verilog code, so it must be somewhat of
> a manual process. I'm just wondering how someone even gets started with a
> process like that.

I'd suggest hitting some textbooks, not Google.

Niklaus Wirth's book is fantastic, for people more comfortable in 
software, if you take it step by step:

https://www.amazon.ca/Digital-Circuit-Computer-Science-Students/dp/354058577X

--Toby

>
> -Swift
>