This post is a short note about a fpga-board project from Luke Wreng (probably know for raspberries Second Memory Device driver). It is a hardware project – if you are interested in FPGA/hardware design this may be for you. Basicaly it is a HAT for your pi … so it is to a large degree ontopic.
There is second reason for this post:
All development for this raspberry HAT is done with his Pi4-4. So it is an „real world“ example to do real work with your pi4-4.
Some further details (schematics, pictures ...):
BTW.: Currently he is playing with dense FPGA designes (especialy his PPU) in Lattice FPGAs and is very busy with CSRs, saving LUTs and number of wires … with OpenSource Tools. Looks like he is interested in FOSS.
Anyway: The „Snowflake FPGA HAT“ may be a good start point for a Crosslink-NX 40K HAT.