Spartan-3E starter kit, what's "J8" 6-pin for?

J8 appears to be labeled on the board as "CPLD JTAG." I don't have my revD board here at home but I looked through the user guide and found figure 2-3, page 16, had a good closeup of that corner of the board

I don't believe this is the "J28" mentioned for an alternate JTAG in the user guide but, instead, part of the super-secret embedded USB JTAG programmer. If you download the schematics separately

you'll find page 3 is intentionally left blank. It's here that the USB chip and supporting circuitry would be found. If you find an undocumented CPLD next to the Cypress chip, you'll probably find its JTAG pins connected to J8.

Have fun with your board!

- John_H

Does anybody know why this page is mysteriously and 'intentionally' left blank?

John.

"It's here that the USB chip and supporting circuitry would be found."

The Xilinx Platform USB cable and associated embedded version is proprietary design information. I imagine Xilinx doesn't want to add the need to support people trying to build their own or complaining when their self-cloned hardware stops working when firmware is updated.

While I would like to see this information made public - with a good way in and out of the development boards through USB for the user - I can understand the headaches that would accompany making this material public. Not everyone understands what "no support provided" means for people who choose to modify or copy the functionality, so it's perhaps best left behind the curtain.

- John_H

perhaps this is amoing others one of the mysteries, Xilinx likes us to explore with this wonderfull board ...

Henk, (owning a SPARTAN 3E board and not knowing, what to to with it ...)