Emulation should be the correct term to use, albeit perhaps not appropriate because it is associated with "Software Emulation".
I used it because anyone re-creating a GPU or CPU today does not re-create the design in the way it was originally implemented. It is never a gate-for-gate recreation. Normally they are not even 100% logically equivalent. Not enough information exists on the original design and technology has moved on. It just has to look like the original from the outside world and how it works under the hood can be and usually is completely different. They emulate the behaviour of the original.
P.S. I'm an RTL design engineer writing VHDL and (System)Verilog for use in FPGA and ASIC on a daily basis for the last 16 years. We have always called the use of an FPGA for a design which hasn't gone to Silicon "Prototyping" and using an FPGA to re-create a design which has been lost (or chips which are no-longer available) as "Emulating". But it gets confusing as there is such a thing as an Emulator for prototyping too where the design is modeled in software on thousands of processors.
But it is just the ambiguous nature of English language.
Last edited by alexh; 01 June 2016 at 18:51.