The FPGA, Micro and Nordic radio all have software. This software is part of the SDK provided by Valve. When you obtain a free license for the SteamVR Tracking HDK/SDK you get access to the software required to program the HDK. When Valve makes updates to the SDK you can download them from your Steam account and apply these updates to your HDK. No software programming required on your part to use the HDK.
If you haven't already you can sign up for a SteamVR Tracking license here: https://partner.steamgames.com/vrtracking/