Question: How should I configure the unused downstream port (D+ and D-) in CY7C65640B/30/20?
Downstream D+ and D- have internal 15K pull-downs and series termination resistors on all upstream and downstream D+ and D- pins. These unused ports (D+/D-) lines can be left floating. The port power, AMBER, and GREEN LED pins must be left unconnected, and the over-current pin must be tied high for the default polarity. The over-current pins are input pins and are not used if the port is not defined in the configuration of the hub. If you leave these pins floating, additional noise may be brought into the chip. It is recommended to tie these pins for the default polarity of the over-current pins.