If so, the limitation 0xFFFF is only for SPI frame.
The command “W 0>FFFF…” is a ALFAT command, it is same for all UART, I2C, SPI and the limitation is up to 0xFFFFFFFF.
they are separated. If you are seeing something in document which let you to be confused, let us know.
Thanks.
Edit:
To more clear, SPI frame can be sent many times to reach the expected length.
But the ALFAT command “W 0>FFFFFFFF.” is only one time, if file size is smaller than 0xFFFFFFFF.