I encountered a problem when I using the cy3684 development board. The problem is that: When I inserted the GAL(U2) into the board, PC could not recognize the board; while everything is OK, when I took out the GAL from cy3684 board. I tried 3 GALs on the board, but neither of them is OK.
For the above-mentioned facts, I did not program the GAL.
My question is that should i program the GAL if i want PC to recognize the board?
Furthermore, if i want to develop a USB device with FPGA and cy7c68013a, should i program the FPGA before connecting the USB device to PC, so that PC can recognize the USB device?
Out of the 3 GAL that you're using are any of them programmed?
The GAL that comes pre-installed in the DVK would be programmed, are you seeing issues even with that GAL?
EA pin which decides the boot mode also is wired to the GAL. So answering whether the DVK will work with an unprogrammed GAL is not that straight-forward. Without the GAL connected the board should work with firmwares that reside in internal memory.
Thank you, aasi.
Neither of the 3 GALs is programmed, and all of them are new.
Before i inserted the GAL into the board, which can be recognized by PC, the voltage of EA pin is 0 V. But when i inserted the GAL into the board, the voltage is 3.3 V, and PC can not recognize the board.
Please see TRM section 5.3.2 128-Pin EZ-USB Chip.
I will see the TRM carefully.
If EA = 3.3V then FX2LP will try to boot from external RAM. Unless you've code in the right format in the external RAM the device will not enumerate. Please use the programmed GAL that came as part of the DVK.