If data must be transferred at ‘high speed’, SPI is clearly the protocol of choice, over I²C. SPI is
full-duplex; I²C is not. SPI does not define any speed limit; implementations often go over 10
Mbps. I²C is limited to 1Mbps in Fast Mode+ and to 3.4 Mbps in High Speed Mode – this last
one requiring specific I/O buffers, not always easily available.