What is the best way to manage software updates if the FT90x is out in the field?

The FT90x can provide a USB DFU interface, meaning that if you connect the USB device controller to a PC, you can use some simple software to update the firmware over USB, meaning that additional programming hardware is not required.

The “blank” chip Bridgetek includes DFU code programmed. Example source code is available to allow users to add this DFU interface to their application code.