I am currently designing with BF607. The USB function will not be used in my design. Is it OK not to power the USB block (i.e. no supply to VDD_USB )? Also, can I leave the unused USB I/O's floating?
You need to have ALL the power domains supplied with the proper voltage even if you are not using them. Any unused USB pins should be pulled low. Refer to the ADSP-BF60x Designer Quick Reference section of the ADSP-BF60x Datasheet, it lists all the pin connections on the BF60x and how they should be connected.