The 9520 is frustrating to use with the uFAT2 package because the means of moving the PERIPHERALSELECT pin from
pin 10 to pin 8 as wired on the board is obscure. There is an error or maybe blunder in the mmc.ccp file that is supplied with the package.
The revised mmc.cpp file fixes this. It should be obvious how to implement additional slaves.
jac