On Sun, 06 Oct 2019 00:29:18 +0200, Luca Ceresoli said:

> BTW I guess having an FPGA external to the SoC connected via SPI or I2C
> is not uncommon. Am I wrong?

Look at it this way - as a practical matter, if you have an FPGA, it's probably
going to be hanging off an SPI, I2C, or PCI.  And if you're an SoC, especially
at the low end, PCI may be too much silicon to bother with.

Oddly enough, I've not seen any FPGA over USB.  That of course doesn't mean
that some maniac hasn't tried to do it.... :)