Configuring Cyclone II FPGA

[Altera_Forum]

Hi Can we configure the FPGA with out using a Serial configuring device? 

 I am using a handheld device and looking to configure the FPGA during run time and remove the Config memory device EPCSxx device.   The device /product will be powered from USB cable connected to a HOST PC and the shall have the option of directily loading the FPGA configuration thru USB interface. The USB interface device has 8051 core. which can communicate to FPGA thru the serial bus.   Is this option is possible and is there any limitation in implemneting this option?

[Altera_Forum]

You would want to wire the FPGA for PS configuration by the USB processor (I guess, it's a Cypress EZUSB device?). If you don't need the FPGA to be operational before the processor is up, it's a flexible method, and quite often used in products.

[Altera_Forum]

Thank you. 

 Yes 'am using Cypress EZUSB device and in my case I don't need the FPGA to be operational before the processor is up. The existing design cypress EZUSB device (IO Pins are) configured to update the EPCSxxx in AS mode for field upgrade. This was done by previous FPGA team.  Since the AS mode interface connects the FPGA as well, can I remove the EPCSxxx device and directly update FPGA every time the Cypress EZUSB device connected to Host PC. i.e configuration file will be on the HOST PC and thru Cypress EZUSB with AS mode directly update the FPGA Each time.   AS mode preferred coz to support backward compatibility as well as change need to support the PS mode.    Also is there any document which can provide more details on how to implement this will be helpful.     I new to this project and beginner in FPG