[vhdl-200x-ft] Numeric_std add_carry proposal

Digging through the e-mail archives, I found one proposal from
2002 that somehow got missed. This one from Rob Anderson (remember him?)
It got missed because it went to the vhdlsynth-pilot reflector, and
not the full reflector.

It's easy for me to implement at this point, and it makes sense.

I'd like to reopen the proposal for
procedures in 1076.3:
------------------------------------------------

Another idea from vhdlsynth (Vallenga) was procedures so that the
carry/borrow bit could be expressed more naturally in the code,
E.G.

procedure addc(a,b: in signed; cin: in std_logic; y: out signed;
                cf: out std_logic);

Procedures are more structural, and they would be helpful for those
vendors like Synopsys (designware), Xilinx (coregen). We did not
add them initially because the package was getting hard to manage,
but now we have a chance to rethink that. I think they would be
popular.

Procedures would mirror the functions, the operations are already
defined. They simply make it easier to put structural clues in
the code.

--Rob

-- 
David W. Bishop dbishop@vhdl.org       All standard disclaimers apply.