Question: Can you hold device (FX2LP™) detection by the host until you request it?
Yes. When the pull-up resistor on the data line (D+) is enabled, the host will detect the device (FX2LP). In the USBCS register, the DISCON bit is used to disconnect the resistor. If you set this bit to ‘1’, the pull-up resistor on the data line (D+) will be disconnected and the host will not detect the device connection. When you want the host to detect the device, set the DISCON bit to ‘0’. For more information please refer to section 15.11.1, “USBCS” in the EZ-USB® Technical Reference Manual.