[vhdl-200x-ft] fixed and floating point package generics

In a off line discussion, we have been talking about how to implement
package generics in the fixed and floating point packages.  Two basic
ideas have come up, which I would like the group to decide between:

1) fixed_base_pkg, float_base_pkg - with no generics
    fixed_generic_pkg, float_generic_pkg - with package generics

    This approach (which we are currently using) offers you a package that does 
not use package generics.  These can be used for base types.

2) fixed_generic_pkg, float_generic_pkg - packages with generics
    fixed_pkg, float_pkg - Instances of the generic packages that would be
    in the IEEE library.

    This approach gives us only one package to worry about.  However there are 
problems with data types in these packages.  You would have to many 
"work.my_fixed_pkg.xxx" type calls if trying to mix your own fixed point data 
types with the default package.


Examples of interfaces:

Approach 1)
Two types.  "ufixed" comes from base package, "uf" comes from generic package.

use ieee.fixed_base_pkg.all;
entity xxx is port (
   aaa : in ufixed (3 downto -3);
   bbb : out ufixed (3 downto -3));
end entity xxx;

use work.my_fixed_pkg.all;
architecture RTL of xxx is
   signal my_aaa, my_bbb : uf (3 downto -3);
begin
   my_aaa <= uf (aaa);
   bbb <= ufixed (my_bbb);
   ..


Approach 2)
One type.  "ufixed" is in both the default and "my_fixed_pkg".
use ieee.fixed_pkg.all;
entity xxx is port (
   aaa : in ufixed (3 downto -3);
   bbb : out ufixed (3 downto -3));
end entity xxx;

architecture RTL of xxx is
   signal my_aaa, my_bbb : work.my_fixed_pkg.ufixed (3 downto -3);
begin
   my_aaa <= work.my_fixed_pkg.ufixed(aaa);
   bbb <= ufixed (my_bbb);
   ..


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