How do they make Verilog code for unknown ICs?

[Ian Finder]

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. Some
ways this can be done:
> If adequate documentation exists, use it.
> Observe the part's behavior in-system
> Build a test bench to observe behavior of part outside of system
> General leetness

There is no one approach, it is more art than science.

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/0071445641

If you have no 100-level understanding of digital logic, start here:
https://www.amazon.com/Contemporary-Logic-Design-Randy-Katz/dp/0201308576

Thanks,

- Ian





On Mon, Jun 20, 2016 at 1:02 PM, Toby Thain <toby at telegraphics.com.au>
wrote:

> 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
>>
>>
>


-- 
   Ian Finder
   (206) 395-MIPS
   ian.finder at gmail.com