RE: [sv-bc] Comments on 285 - initialization of unions

The issue is that unpacked union members do not have to be the same size.
The other members may be larger than the first member.

typedef union { logic [7:0] b; logic [31:0] i; } UT;
UT u;
initial $display(u.i);

What is suppose to be the result here? Is it undefined, and implementations
may do
different things? If that is the case, I think we should say that more
clearly.

  -----Original Message-----
  From: owner-sv-bc@eda.org [mailto:owner-sv-bc@eda.org]On Behalf Of Rich,
Dave
  Sent: Saturday, November 20, 2004 9:20 PM
  To: sv-bc@eda.org
  Subject: [sv-bc] Comments on 285 - initialization of unions

  Regarding the comments from Mark and Surrendra via the email vote

  285 ___Yes _x_No
  http://www.eda.org/svdb/bug_view_page.php?bug_id=0000285
  I think this description applies to packed unions, but it is not
  clear how it applies to unpacked unions.

  I don't see why the proposal needs to address packed or unpacked unions
specifically. An initialization behaves like an assignment, so the values of
the other members of an unpacked union are undefined.

  Dave
Received on Sat Nov 20 22:47:13 2004