I would like to know the answer to that as well. I did see elsewhere in the forum that you can implement SPI in software using GPIO. I would like to know why the SPI function and 32-bit FIFO conflict.
SPI can be used for Booting purpose, even you configure the GPIF II with 32-bit in the firmware.
Booting process explained here
When ROM Bootloader samples the PMODE lines (0Z1) and it comes to know that it has to boot from the SPI Flash.
Therefore, it boots the Firmware to System RAM.
Once the firmware image has been completely transferred, the FX3 bootloader automatically jumps to the
entry point of the newly downloaded firmware and starts executing.
Then, all the blocks will be configured as per the FIRMWARE Loaded from SPI.
Once it is configured, GPIF II with 32-bit data bus, SPI Block will not be available for any SPI Communication.