[Magic-dev] Re: invert simulation isn't working as should

[Philippe Pouliquen]

Hi Chitlesh,

You've got a pretty basic problem: you don't understand how to drive 
Irsim.

I did not look at your layout, because you didn't specify a tech file, but 
the invert.sim file looks fine, so the layout is basically irrelevant. 
It looks to me like all the problems are in example.cmd.  Take a look at 
the following lines for example:

> vector in in1 out

This defines a 2 bit vector composed of the signals in1 and out.

> h in1

This sets signal in1 to 1 (high).  So far so good...

> set in 00

This sets bit vector in to 00.  That is, it should set in1 to 0 and out to 
0.  Why you would want to force the output to a given state is beyond me.

> s

You should now get in1=0 and out=0.  (You actually get X's, but that's for 
another reason).

Try the following more basic command sequence instead:

irsim scmos100 invert.sim

h Vdd!
l GND!
w out
l in1
s
h in1
s
q


BTW, if you want to avoid having to set the power supply (Vdd! and GND!), 
label them Vdd and Gnd instead.

Philippe Pouliquen
The Johns Hopkins University