VDDxSPI Pin connection when not used

[STesil]

Hello all,

we are using the STM32H7S3Z8T6 in a project. It has four VDDxSPI pins for an external power supply if XSPI is used. I also found some information in app note AN5935.

However, we are not using external memory and therefore we don't need an additional power supply. Unfortunately I didn't find any information on what to do with these pins if XSPI is not used. Leave them open? Connect to Gnd? Connect a capacitor? 

And an additional question: the "normal" SPI buses are not powered by VDDxSPI right? Those pins are just for XSPI?

[STesil]

My guess would be that XSPI will get powered by the internal LDO and the VDDxSPI pins should then be decoupled with 100nF Caps to GND