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Hi,
I have a Saxo-L board which I have modified so that I can use the JTAG interfce from USB blaster. I have basically disconnected the JTAG lines between FX2 and the FPGA and through jumpers, I can either select JTAG-over-USB via FX2 or directly the USB-blaster.

I am using EZ-USB to send/receive data. My test program writes few bytes to FX2 FIFO2 and the FPGA writes few bytes back to FIFO4. Everything works fine when I configure the FPGA using FPGAconf.exe (via FX2 JTAG interface).

When I configure the FPGA directly using USB blaster, the USB_BulkWrite function fails (program terminates at assert(nBytes==buffersize) ). If the FPGA is not configured properly, I would expect the reading part to fail.

The same problem happens if I try to write to FX2 FIFO2 without configuring the FPGA (just after power-up).

My question is: How is writing to FX2 FIFO2 affected by whether FPGA is configured or not ? I expected FIFO2 writes to always work (as long as there is space in FIFO) irrespective of whether FPGA is configured or not.

Thanks.

That's because when you use the USB blaster, you configure the FPGA but not the FX2, so the FX2 FIFOs won't work.

Thanks for the reply.

So how do I configure FX2 so that I can send/receive data to the FIFOs? Is there any sample C/C++ program or tool that can do this? I did not find any option in FPGAconf.exe to configure FX2 alone.

Thanks.

FPGAconf_console should do that - simply use the "board" parameter to specify your board and that should initialize the FX2 alone. Make sure you are using the latest version of FPGAconf_console.

I am not sure if I have the latest version of FPGAconf_console. The version I am seeing is 2.07.10. I got the board couple of years back. Can you please send me the link to download the latest version?

I tried the FPGAconf_console that I have but was not fully successful...only sometimes I am able to connect and when I do connect, I get a different a result compared to using JTAG with FX2. May be there are other issues but first would like to get the latest version of FPGAconf_console.

Thanks,

Latest version is 2.12.04 - send an email to KNJN to get it.

The latest version of FPGAconf_console.exe has solved all problems. I even got the CyUSB driver to work, which I was not able to use with version I had earlier.

One last question...I am currently using system() call to configure FX2 from my program. Is there any sample code that I can get to configure FX2 form within my program so that I can avoid the command window pop-up? Not ciritical, just asking.

Thanks for the help.