[vhdl-200x-ft] Some notes from last night's telecon -- David Bishop #1

David Bishop posting from

-------- Original Message --------
From: David Bishop <dbishop@server.vhdl.org>
Subject: Some notes from last night's telecon

Notes from last night telecon. Some of these deserve discussion.

_reduced operators - These are currently implemented in a loop.
Reimplement as recursive functions

In the to_string functions modify so that there is a
--rtl_synthesis off and on around the unsynthesizable
part of the function.

Rewrite 1164 CP-007 - Moved the procedures in std_logic_textio
     to std_logic_1164.

Change the "match" function to be "=?" operator

Replace the "to_signed(unsigned)" and "to_unsigned(signed)"
functions with "add_sign" and "remove_sign" functions. New Proposal?

Currently "numeric_unsigned" and "numeric_bit_unsigned" are
independent of "numeric_std" and "numeric_bit". The suggestion
was made last night to make them dependent. Will modify the
functions these to packages to call out the functions from the
base package. This prevents code replication and allows us
to be synthesizable without the synthesis vendors having to
build in our code.

Fixed point package:
Modify boundary checking "min" and "max" routines (hidden routines)
in the package to return an error if integer'low is passed to them.
This will be done because of you do "uf7_3 := uf6_3 + "001"; the
default range on the "001" will be integer'low to integer'low-2.

Replace the "to_sfixed(ufixed)" and "to_ufixed(sfixed)"
functions with "add_sign" and "remove_sign" functions.
This will allow:
uf7_3 := uf6_3 + to_ufixed("001");
to work (where "001" will be considered an unsigned.

Removed operators which mix ufixed and sfixed. Force the user
to convert.

Add a range on the operators which mix ufixed and real to prevent
a negative number from being passed.

Add a "vector truncated" message to the conversion routines.

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