Re: [Help-gnucap] Subcircuit problem

[al davis]

On Saturday 01 December 2007, a r wrote:
> On Dec 1, 2007 2:05 PM, al davis <address@hidden> 
wrote:
> > > Any ideas?
> >
> > You have the connection order messed up?
>
> No, the connection order follows Spice syntax and Gnucap
> docs. Try simulating the code I included.
>
> > How about changing to:
> >
> > "xckgen ckgen out in"
>
> "can't find subckt: in"
>
> Note that "inv" and "nand2" subcircuits work just fine. It's
> only "cktgen" that makes problems.
>
> In fact, the circuit with instantiated "cktgen" subcircuit
> _does_ simulate. I only gives different results (v(out) looks
> like buffered v(in)).

It was early in the morning.  I just got up and was not fully 
coherent yet .....

This illustrates why I like the Spice format so much :-)

X1 a b c d e f g h 

Clearly, a,b,c are connections .. d is the name of the .subckt 
being called ..  e=f and g=h are setting parameters.  It's 
obvious, isn't it??????

But back to your problem ....  I see it now.....

> .subckt ckgen out in
> xr1 vdd vss n2 n1 inv
> xr2 vdd vss n3 n2 inv
> xr3 vdd vss n4 n3 inv
> xr4 vdd vss out n4 inv
> xnand2 vdd vss n1 out in nand2
> .ends ckgen

"vdd" and "vss" are local nodes, with no connection to outside.  
When you flatten it, you make the connection.