There are three ways to download the firmware
(1) Firmware download from host (Using the control panel host application for example)
(2) Firmware upload from EEPROM ( Perform a C2 boot load). See the TRM chapter 3 for more details on this
(3) Using the custom loader driver. See the EZLOADER Custom Firmware Loader Driver application note.
(4) External Memory. External EPROM, flash can be used. This is limited to EZ-USB FX. 64 KBytes can interface directly to our device without external logic. Large memory can be supported using programmable I/O pins and other paging techniques. Please open a support case for a specific example on interfacing with flash.
(5) Using Scripting method.See application note on Downloading FX2LP/FX1 Firmware Using CyConsole Script Capabilities