Jtag SLD Hub now officially documented

I'm not using my own controller, at least not a hardware controller as when using a micro to control the Jtag interface. I am accessing virtual jtag nodes from a PC at the application level.

Before this update, the only documented way to access the SLD hub was using TCL scripts. TCL scripts are good enough in many cases, in others you need your own application.

In my specific case, if Altera would provide a documented API at the C level, then I wouldn't really need the SLD hub low level info. Short of that API, I used the SLD hub infrastructure, accessing the FTDI USB Blaster driver directly.