Boot load from EEPROM with a firmware larger than the internal memory of EZ-USB (AN21xx/FX/FX1/FX2/FX2LP)

Question: EZ-USB (AN21xx/FX/FX1/FX2/FX2LP) while boot-loading from the EEPROM can write only to internal memory. How can I boot-load a firmware larger in size than the internal memory?

 

Answer:

What needs to be done is a two phase process.  The first phase is to have the EZ-USB boot-load a boot program that is capable of writing to external memory.  The second phase is for this boot program to read from EEPROM and write to external memory the part of firmware which has to reside in external memory.

Using the –e parameter of hex2bix utility this can be achieved.

Note:- The internal RAM of the older parts AN21xx/FX is 8k and that of the newer parts FX1/FX2/FX2LP is 16k.