Re: [sv-ec] SV: class instance inside an interface

Dave,
Here is code that fals to compile when the class instance is used in an 
assertion.
It seems OK in the assignment though.  ???

class configuration;
  bit addr = 1;
endclass:configuration

interface itf (input logic Clk, input logic Rst);
  logic [7:0] A ;
  logic [2:0] B ;

  configuration cfg_local=new;
  initial A[0]=cfg_local.addr;  // Compiles OK HERE
  // some checker:
  property signal_valid (A, clk, B, addr);
    @(posedge clk)
    if(addr)
    |A |-> !$isunknown(B);
  endproperty

  assert_signal_valid:
     assert property (signal_valid(A, Clk, B, cfg_local.addr)) // here 
is the compile error
    else $display($time, " signal_valid failed.");
endinterface: itf


** Error: test.sv(19): (vlog-2110) Illegal reference to class 
"cfg_local".


-----Original Message-----
From: Rich, Dave <Dave_Rich@mentor.com>
To: vhdlcohen@aol.com; sv-ec@server.eda.org
Sent: Mon, 10 Jul 2006 09:02:06 -0700
Subject: RE: [sv-ec] SV: class instance inside an interface

  A class is a kind of data type (section 4.12), and you can declare a
class anywhere it is valid to declare data type. I don't think there is
any ambiguity.

Dave


> -----Original Message-----
> From: owner-sv-ec@server.eda-stds.org [mailto:owner-sv-ec@server.eda-
> stds.org] On Behalf Of vhdlcohen@aol.com
> Sent: Monday, July 10, 2006 8:22 AM
> To: sv-ec@server.eda.org
> Subject: [sv-ec] SV: class instance inside an interface
>
>  From Adrian Coman,
>
http://verificationguild.com/modules.php?name=Forums&file=viewtopic&pT6
> 1#5461
> The SV LRM doesn't say anything about classes inside interfaces, only:
> Quote:
> Page 349, IEEE Std 1800(tm)-2005: An interface can have parameters,
> constants, variables, functions, and tasks.
>
> So it doesn't specifically forbidden the usage of classes inside
> interfaces.
> _________________
>
> I agree with you that the LRM is ambiguous. I did a quick test on a
> simulator, and it compiled OK.
> Translation: As of right now, it's a matter of interpretation. But
> logically, in some respects interfaces are similar to modules in that
> they can have arguments, tasks, and temporal properties, among other
> things. Thus, since modules can have class intances, why should the
> interfaces be excluded. It seems that this is the path that vendors
are
> taking.
> Ben Cohen
>
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