newbie seeking help to use xilinx spart-3a starter kit

Maybe that's different with your Spartan 3A starter kit, but with my Spartan 3E starter kit, there was only one USB connector, which is connected to a CPLD, which just converts the USB data to JTAG for programming the FPGA and the flash. There is no boot up menu (but there is a FPGA configuration flashed for board demo), it's all hardware and you have to write your own. You write VHDL code, which then controls the board, same as if you would use lots of logic gates.

The hardware configuration (synthezied VHDL programs) is programmed via the USB interface and then you can use minicom to connect to your hardware, if you have written some VHDL program for the serial port, like this one:

(note: this is old code, the serial port program is a bit unsafe, at least it didn't work stable for a Cyclone, unless I added a latch for the RX input and today I would write it less complicated, Whishbone doesn't make sense for such simple and synchronous designs with one clock).

I've seen some hacks for the CPLD to use the USB port on the board for other things, but Xilinx didn't described the internals, like many other informations are not published by FPGA vendors, maybe because of trade rivalry, which is really cumbersome for developers like me, who wants to understand and use it down to the lowest level, if necessary and maybe for other tasks than the vendors have thougt for which it can be used and with other tools than the vendor synthesize tools.

I used the quick start tutorial and indeed I can now program the board. It's amazing!

Fei