Re: [Discuss-gnuradio] USRP2 JTAG functionality [was Exposing more JTAG functionallity in FX2firmware]

[Eric Blossom]

On Mon, Mar 31, 2008 at 11:25:56AM -0600, Jeff Brower wrote:
> 
> > On Mon, Mar 31, 2008 at 11:46 AM, Uwe Bonnes
> > <address@hidden> wrote:
> >> Hello,
> >>
> >>  has there been any effort to expose more JTAG functionality via the FX2 so
> >>  that the USRP FX2 firmware could be used with modified other JTAG 
> >> software,
> >>  like xc3sprog.
> >
> > As far as I can tell, not without some hardware modification.
> >
> > According to the schematics found here:
> >
> >     
> > http://gnuradio.org/trac/browser/usrp-hw/trunk/usrp/interface.pdf?format=raw
> >
> > The JTAG section of the FPGA is pulled either high or low and has no
> > other connections.  You're obviously free to do what you want with
> > your hardware, but I don't think you'll get much extra support from
> > the mailing list?
> >
> > I could be wrong, so please have at it!
> 
> This reminds me of a question I have about USRP2.  My understanding is the 
> USRP2 has a Xilinx Spartan 3, which I don't
> think come in anything other than BGA packages.  Hopefully Matt brought the 
> JTAG lines out in case people want to
> deadbug a header and use standard tools.  Even better would be the 0.1" holes 
> to install a header if desired.
> 
> -Jeff

Not sure about JTAG connectors on the USPR2, but it does bring out
64-bits that you can do with as you like.  32 on a mictor connector
and 16 each on the Tx and Rx daugterboards.  We generally wire them up
to a logic analyzer when debugging.

Eric