[Tutor] Processor Simulator

[Michael P. Reilly]

Timothy M. Brauch wrote
> I have a project for my comp-sci class.  I have to design a simulator
> for a processor, and I've decided to use Python.  So, my question is,
> does anyone have any suggestions as to how to go about doing this? 
> Also, I have to write simple files and load them into my simulator.
> 
> My initial thoughts are to create a class with a bunch of function
> definitions for different processes.  Such as add() and sub() and mul(),
> etc.

I would try to break different components into separate classes.
For example, a class for an ALU, another for external memory (maybe with
methods for "read" and "write", especially if you are simulating a RISC
type processor ;)), maybe one for a pipeline (later).  Then you could have
the one "processor" class as the control mechanisms for the components.

But above all.. keep it simple.  This seems oxymoronic, but as I suggest
above, instead of making some big list to simulate possibly megabytes of
RAM, just make read/write methods (there will be comparable load/store
commands anyway).  Don't introduce a cache or special features at first;
as attractive as it might be to code, doing so might distract from the
"real" features.

> I also have to have a display window showing register enteries, which
> that I think I can do fairly easily.  I was thinking of using the latest
> VPython which has a text function (I am doing this mostly because I have
> no experience with TK, otherwise I would use it, but right now I don't
> have the time to learn it).

At first, I would just concentrate on the class(es) for the processor
and worry about a user interface later.  The project is not a graphical
program; keep display in mind while you are designing your program,
but keep the focus on the goal.

> As for the files, I would use something like readlines and string.split
> to break up my commands kept in the external file.  I think I can handle
> that as well.

That sounds fine, especially at first.  Also look at string.strip to
"nicely" get rid of the whitespace (including the line terminator).

Good luck! :)

  -Arcege

-- 
+----------------------------------+-----------------------------------+
| Michael P. Reilly                | arcege@speakeasy.net              |