Communication between Cyclone III FPGA and PC vis USB(on board)

[Altera_Forum]

Dear Madam/Sir, 

 My name is Peipei Hu, from the University of Manchester, UK. I am doing a project relates to FPGA Cyclone III.   Basically, I use Cyclone III FPGA Starter Board(EP3C25F324) and daughter board of HMSC ADA GPIO board. The objective of the project is to generate 25 different frequencies from FPGA to my measurement system via daughterboard and receive the signal back to FPGA. Then communicate with PC which means I need an interface in my PC to control the system.   Now, I can generate the signals and I can check them via scope correctly. But I have no idea how to communicate between PC and FPGA board. I searched for long time, and based on the information of user-guide, I found the USB (J3) can be used as download port and communicate port. But I do not know how to realise this function. I have put the question on the forum without response. SHould I use IP core(no experience on IP Core) or should i use Nois II?   So is there anybody has examples and tutorials relate to my problem?   I am looking forward to hear from you.   Thank you very much.   Best wishes,   peipei

[Altera_Forum]

The simplest way is to use and FTDI chip and communicate to this via a serial interface. Many of the development boards take this approach. Look at the reference manual https://www.altera.com/en_us/pdfs/literature/manual/rm_ciii_starter_board.pdf it appears the board has a USB to serial chip on board. But it appears to be used by the USB blaster interface.. It hints that it's also available for user mode operations, but without going over the schematic I can't say for sure. 

 But if you are doing a HSMC board anyway, simply add an FTDI chip like the FT232R device to your board and run build a uart into the FPGA to talk to the outside world.  Drivers for FTDI USB to Serial devices are built into windows/linux so do you don't need to mess with that side.  Pete

[Altera_Forum]

There's basically an option to communicate through USB blaster and virtual JTAG functions (e.g. source & probe, in-system-memory editor, JTAG UART). But support on the PC side is very limited, only scarce applications for the JTAG UART have been published so far. The starter board "control panel" is accessing virtual JTAG functions through undocumented alt_jtaglib.dll on top of Quartus jtag_client.dll. 

 You should also review previous threads about this topic, e.g.  http://www.alteraforum.com/forum/showthread.php?t=2199 http://www.alteraforum.com/forum/showthread.php?t=1686 http://www.alteraforum.com/forum/showthread.php?t=4256  In any case, implementing an UART interface on the development kit and connecting it through a FTDI USB-to-UART bridge is a straightforward solution.