BTF BE84 - Function and Register name errata to review

From: Anders Nordstrom (andersn@nortelnetworks.com)
Date: Thu Jun 24 1999 - 07:50:18 PDT

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Please review the enclosed proposal for errata BE84 and vote to the reflector via email before
June 30.

Regards,

                Anders

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<H2> BE84 - Function and Register Name Errata</H2>

<TABLE BORDER COLS=2 WIDTH="75%" >
<TR><TD>
Section: </TD><TD> 10.3.1 and 10.3.2 (Draft 2)
</TD></TR><TR><TD>
Date Submitted: </TD><TD> 990429
</TD></TR><TR><TD>
Requestor: </TD><TD> Mike McNamara
</TD></TR><TR><TD>
Status: </TD><TD> Proposal
</TD></TR><TR><TD>
Analyzed by: </TD><TD> Mike McNamara & Anders Nordstrom
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<H3> Details </H3>

One of our users just got tripped up by this one. I looked in the
standard, but it is not clear.
<BR>
They had code that essentially was:
<PRE>
module test(a,b,c);
  input [7:0] a;
  input [2:0] b;
  output [2 : 0] c ;
 
  assign c = problem(a,b);
 
  function [2 : 0] problem ;
    input [7 : 0] a ;
    input [2 : 0] b ;
    reg [2 : 0] problem ;
  begin
    problem = b + a;
  end
  endfunction
 
endmodule
</PRE>
VCS happily accepts this code, VXL gives an error message.

Of course VXL is right, we all know that you cannot define a register
with the same name as the function, because, in truth, there is
already one implicitly defined by defining the register.

I feel we should add language that explicitly states that one cannot
declare another object with the same name as a function in the scope
where the function is declared (I.E, in the module) or inside the
function.

-mac

<PRE>
From: asingh@cupertino.synopsys.com (Ajay Singh)
To: spear@synopsys.com, vcs_support@synopsys.com, btf@boyd.com
Subject: Re: vcs/18556 : Function contains register with same name
</PRE>

Hello Chris Spear,

An Enhancement request TR 3323 is filed for this PR.
I am closing this PR for now.

Thanks,

Ajay

<p><H3> Proposal </H3>

Before the last sentence in section 10.3.2 on page 144 in Draft 2 add:

It is illegal to declare another object with the same name as the
function in the scope where the function is declared or inside
the function.

I also found another minor errata in section 10.3.1 of Draft 2 only.

Change the word <B>endtask</B> to the word <B>endfunction</B> on the
third line in the section below Syntax 10-3 on page 143 of Draft 2.

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