I decided to order the explorer kit, might be an interesting exercise even if there is some problem. Will have to figure out some way to do the demultiplexing though, but one step at a time.
Nils Roos wrote:I, on the other hand, have not been looking very thoroughly at the EZ-USB FX3.
The "SuperSpeed Explorer Kit" for this chip retails for 50-60$ and offers nearly everything you would need. If you are confident that running parallel data over the GPIOs is possible at 200MHz, you could pack and multiplex the sample data onto the GPIOs at 200Mhz and demultiplex to a 100MHz 32bit GPIF II interface with some external circuitry.
The devkit takes it from there, it can be configured to automatically gather the GPIF II input into bulk transfer packets, you'll just have to collect the data from the driver on the host end and unpack it.
The downside is that even at 32bit width the GPIF II interface does not quite support the full data rate that the Red Pitaya can generate.