These packages were designed as a bridge between VHDL-93 and VHDL-2008.   I replicated as many of the new functions as possible.   Note that all of these packages are design to be synthesizable in VHDL-93.   So, as long as you stick to the subsets defined in the "README" files for the various vendors you should be able to take your code through the entire flow.

VHDL-2008 is finally getting some traction.   What started out as just a fixed and floating point package got merged into the VHDL LRM.   On this page you will find definitions of the functions available in the VHDL-2008 libraries.   You will also find VHDL-93 compatible code for those that do not yet have access to VHDL-2008 compilers.

There is a Fixed Point user's guide and a Floating Point user's guide.   Please check the Fixed and floating point FAQ (NEW!) if you have any quesiton.

The VHDL-2008 packages will eventually be included in your vendor's environment. In some cases I have found that they may be encrypted due to IEEE rules. The packages available on this page are NOT the released packages, but VHDL-93 versions of those packages, which I published BEFORE the release of the LRM. They are free of copyright restrictions, and may be used for whatever purpose is needed.

VHDL-93 versions of the VHDL-2008 packages

• Additions to std.standard standard_additions_c.vhdl (user's guide)
• New package std.env env_c.vhdl
• Additions to std.textio standard_textio_additions_c.vhdl (user's guide)
• Additions to ieee.std_logic_1164 std_logic_1164_additions.vhdl (user's guide)
• Additions to ieee.numeric_std numeric_std_additions.vhdl (user's guide)
• New package numeric_std_unsigned numeric_std_unsigned_c.vhdl (user's guide)
• New package fixed_float_types fixed_float_types_c.vhdl
• New package fixed_pkg fixed_pkg_c.vhdl (Fixed Point user's guide)
• New package float_pkg float_pkg_c.vhdl (Floating Point user's guide)
• ZIP file of all the packages (updated 09/2010)

I use this code in most of my designs. Many times I find that I have to modify the code slightly in some tools, so I made this list. Included in the "source code" section for each tool is source code specifically debugged for that particluar tool. Click on the "documentation" link to see what changes I had to make, and how to use this code in the specific tool.

Some helpful code to go with these packages:
• fixed_noresize.vhdl Similar to "fixed_pkg", however this version uses the same rules that numeric_std does for the size of the result. This is done by calling the funciton in "fixed_pkg" and resizing the result.
• float_noround_pkg.vhdl Similar to "float_pkg", however this version turns off all of the IEEE rounding and overflow, and defaults to a 26 bit floating point number. This package saves off 1/3 of the logic needed for full 32 bit floating point.
• fixed_synth.vhdl Synthesis testcase for the fixed point package.   test_fixed_synth.vhdl Testbench for the fixed point synthesis testcase.
• float_synth.vhdl Synthesis testcase for the floating point package.   test_float_synth.vhdl testbench for the floating point synthesis package
• Testbenches to verify an implimentation of VHDL-2008.
• Matrix Math package for type REAL which has a user guide (Done in conjunction with IEEE 1076.1 VHDL-AMS)

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