RE: Why is type for string parameters mandatory?

They can be considered regular 24 or 32 bit unsigned vectors.

 

Shalom

 

________________________________

From: owner-verilog-ams@server.eda.org
[mailto:owner-verilog-ams@server.eda.org] On Behalf Of Marq Kole
Sent: Thursday, November 16, 2006 10:29 AM
To: verilog-ams
Subject: Re: Why is type for string parameters mandatory?

 


Geoffrey, 

> things like
>   if (myParam == "nmos")
> since both sides would be (converted from string literal to)
> the same 24-bit integer value.

I would say that the string "nmos" would be converted to a 32-bit
integer value. 

If these string literals are converted to packed arrays of 8 bits, are
these 24-bit and 32-bit integers interchangeable with ordinary integers?


Cheers, 
Marq 


Marq Kole
Competence Leader Robust Design

Research
NXP Semiconductors









"Geoffrey.Coram" <Geoffrey.Coram@analog.com> 

Sent by: 
owner-verilog-ams@server.eda.org 

15-11-2006 15:21 

To

Dave Miller <David.L.Miller@freescale.com> 

cc

verilog-ams <verilog-ams@server.eda-stds.org> 

Subject

Re: Why is type for string parameters mandatory? 

Classification

 

 

 

 




Dave -
If you did
 parameter myParam = "abc";
and AMS didn't disallow this, it would still have to convert this
to a 24-bit integer.  I guess you would still be able to test
things like
 if (myParam == "nmos")
since both sides would be (converted from string literal to)
the same 24-bit integer value.

I would say, though, that AMS allows you to do
 parameter string myParam = "abc";
since it extends digital 1364, and also you should be able to
use the == and != operators, I don't think they're restricted
to the analog block.

-Geoffrey


Dave Miller wrote:
> 
> Okay so Shalom's comment that parameter myParam = "abc" declares a
24bit
> vector makes sense as to why it works in digital. I just looked at it
as
> they have allowed string parameters without declaring the type which
was
> not quite right.
> 
> Digital explicitly disallows me to declare a string parameter as:
> parameter string myParam = "abc";
> 
> Analog currently explicitly disallows me to declare a string parameter
as:
> parameter myParam = "abc";
> 
> Because parameters are at module scope and hence domain less (well
thats
> how I look at them) this creates some conflict if I happen to want to
> use the same parameter in both domains.
> The biggest use I am seeing for string parameters today in my work is
in
> test benches where they are being used for error messages and to store
> the filename of a file to be used in a $fopen() statement.
> 
> Dave

-- 
Geoffrey J. Coram, Ph.D.    Senior CAD Engineer     
Analog Devices, Inc.        Geoffrey.Coram@analog.com 
804 Woburn St., MS-422,     Tel (781) 937-1924
Wilmington, MA 01887        Fax (781) 937-1014