RE: Analog function question

Re the statement that "you cannot set a parameter value (of a function)
from the outside", 

I think there are 2 ways that you CAN do it:

 

1.	defparam
2.	Use a parameter which is defined in the module enclosing the
function. That parameter value CAN be overridden.

 

Shalom

 

 

________________________________

From: owner-verilog-ams@eda.org [mailto:owner-verilog-ams@eda.org] On
Behalf Of Marq Kole
Sent: Friday, September 16, 2005 10:28 AM
To: verilog-ams
Subject: Re: Analog function question

 


Oops, need to correct a small mistake below: 

> Sri, Arpad, 
> 
> > In strict accordance to the BNF it cant be done yet. I think it was 
> > an oversight/bug in the BNF and the intent was to put it in there.
> 
> In accordance with the BNF, the input declaration is mentioned as a 
> digital_input_declaration in Annex A, so its actual definition is in
the 
> IEEE 1394-1995 standard. See Mantis item #870. 
> 
> For array arguments see Mantis item #869 describing the problem - it
is 
> rather an issue of documentation (explanation + example) than a
missing 
> item in the standard. 
> 
> > 
> > regards,
> > Sri
> > 
> > Muranyi, Arpad wrote: 
> > Sri,
> > 
> > I just saw your 2nd reply, but since I had this almost finished,
> > I will send it out anyway...  So according to your 2nd message,
> > this can't be done (yet)?
> > ----------------------------
> > Thanks for the quick answer.  Sorry, but I am still not sure
> > about it.  The sections you quoted from the LRM seem to allow
> > the array inside the function as a block item, but I still
> > don't see how I can pass an array into the function (and
> > pass it as a real variable array, not as a parameter array).
> 
> Parameter arrays in functions wouldn't help you anyway, as you 
> cannot set them from outside the function, and once initialized, 
> you cannot alter them from inside the function either. 
>  
> > Would you be so kind and help me with an example?  If the
> > input "in1" is an array, how would you declare it in the
> > function?
> > 
> > analog function real myFunctionName;
> > input in1;
> > real  in1[1:5];    <--------- How would I know the size?
> 
> You'd know the size as the above analog function declaration tells 
> you the size. There is at this moment no way to make an array argument

> with parameter-controlled size in an analog function in Verilog-AMS --


I mean an argument-controlled size given the fact that you cannot set 
a parameter value from the outside. So a call: 

  myArrayFunction(myArraySize, myArray); 

Where myArraySize argument carries the length of the myArray argument 
cannot be handled in current Verilog-AMS. 

> we need to check what System-Verilog does to resolve that for a future

> LRM, I think. 
> 
> > begin
> > ...
> > ...
> > end
> > endfunction
> > 
> > 
> > Thanks,
> > 
> > Arpad
> 
> Marq Kole
> Competence Leader Analog Simulation, Philips ED&T