ID: Input. Leave floating if unused or TUSB1210 is Device mode only. Tie to GND through RID < 1 kΩ if Host mode.
REFCLK: Input. If REFCLK is unused, and 60 MHz clock is provided by MODEM (60 MHz should be connected to CLOCK pin in this case) then tie REFCLK to GND.
CFG: Tie to GND if REFCLK is 19.2 MHz, or
tie to VDDIO if REFCLK is 26 MHz. Tie to either GND or
VDDIO (does not matter which) if REFCLK not used (for
example, ULPI input clock configuration).