In my book, “VHDL for Logic Synthesis“, I make extensive use of the VHDL-2008 extensions for fixed and floating-point numbers.
However, many synthesis systems do not necessarily provide these packages. For a while it was possible to use them by downloading them from VHDL.org but that website is now closed.
To make this simpler, I have added download links below to the packages:
- Cadence NC VHDL
- Cadence RC
- Xilinx 11
Each variant has notes included explaining how to use them with that particular synthesiser or simulator.