What is FPGA Programming?
FPGA programming is different to software programming, in that it is primarily hardware-based. The language used to aid an FPGA is called Hardware Description Language or HDL. This FPGA coding language is used to design and modify the behaviour of an FPGA. Where coding and HDL programming differ is in their application. Whilst coding comprises and amends software, HDL will make a physical change to the hardware.
FPGA Programming Language
Whilst there are several language options when programming an FPGA, the most common are Verilog and VHDL. For a simple explanation, Verilog is structured around cause and effect or verification and logic. This language is great for simpler circuits that need to amend a simple hardware function. This differs from VHDL, which is a language designed to work best with high-speed integrated circuits, and therefore is more effective in complex FPGA uses.
How to Program FPGA
The first step to programming an FPGA is to choose your HDL language. There are many to choose from as the market for FPGA has increased substantially, though if you are using a software platform to help you with your programming, this may dictate what language you need to use.
The second step is to break down the commands into bite-sized pieces, so every part of the FPGA has its own function that works toward one goal, rather than the entire FPGA being one big, complicated circuit.
From there, it is a process of writing the function of each module in the code, making sure you declare an input and an output so that the circuit is completed and the command can reach the device. Once this is written, the process is still the same in all cases – the language needs to be converted to binary code in order for your FPGA to process it. FPGA is so versatile that the code you have written can be amended or reverted if the outcome wasn’t the one you were hoping for.