When you say MSC firmware I assume you're talking about CY4640 firmware for Ez-Host. This configures Ez-Host as a mass storage host.
Are you using this firmware "as is" or made any modifications to it?
I have read ANI5484 and AN70973 in the www.cypress.com and I want to use cy7c67300 to read data from an USB Flash Drive, my development board is a custom board. I used the msc firmware of the cy4640 development kit without any modifications.I have found the source code at the USB/OTG—Host/Source/stand-alone/msc,and I used the gun tools to build it and loaded it into the EEPROM! But the PC can't identify the usb device(cy7c67300,vid=04B4,pid=7200) after I did it. To my surprise,I have tried to load other example codes in the USB/Host/Source/stand-alone,and the result is same as msc firmware,the usb device was missing unexpectedly after the code was loaded into EEPROM！I really don't know about this,could you help me?