RE: [sv-ec] Comments on 890-5.pdf

From: Jonathan Bromley <jonathan.bromley_at_.....>
Date: Tue Feb 13 2007 - 01:05:14 PST
> I think restricting the value non-negative signed expression 
> is better.
> If you treat the expression as unsigned, you will never see a negative
> number, so your warning could never be issued.

OK, good point.  But we don't want sensible, narrow, unsigned
values to be treated as if negative just because their MSB
happens to be set...  

logic [7:0] delay = 8'h80;  // +128, not -128
...
#delay ...

So the signing of the expression must be self-determined, 
and if it's signed and negative then we stipulate an error. 
I still think the error should be non-fatal, and the
delay performed by the tool should be the unsigned'() 
value of the expression.
-- 
Jonathan Bromley, Consultant

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Received on Tue Feb 13 01:06:17 2007

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