IrDA is a set of protocols for exchanging data over infrared light. It’s significantly more complicated at the protocol level and hardware level than simple IR transmitter like remote controls. To get started in IrDA you’ll need some software to encode and decode packets, Microchip describes their IrDA stack in this app note:
The Microchip IrDA Standard Stack provides a modular, easy-to-use set of libraries to add support for an IrDA standard protocol to your application. The low-level drivers allow the Stack to be tailored to the target hardware, while the libraries keep the Stack interface simple. The Microchip IrDA Standard Stack will allow you to add a valuable connectivity aspect to your embedded design.
The Microchip stack might be useful for learning, or certain commercial projects, but keep in mind that it’s not open source friendly.
“Microchip only support SIR transmission speeds” ie. max speed of 115.2kbit/s. For a moment there, I thought I had found a way for an FPGA to communicate at USB high speed, without an actual USB port. Oh well.
Maybe someone will produce a UFIR (96Mbit/s), or GigaIR (512Mbit/s) version. Or optic fibre – that would make an interesting read…