[Discuss-gnuradio] usrp fpga possibilities and tvrx specs

[Martin Dvh]

Hi,
Is it possible to tell the usrp to only send 8 or 10 bit samples or only the 
real part of the signal.
(Is this at all possible with the current firmware?)
Or is there any documentation of the blocks in the fpga code and the 
usb-controller firmware and how to use them.
I looked at the usrp manual and the usrp sourcecode but it is still not clear 
to me.

background:
I am working on the TV code and other high-bandwidth blocks and am having usb 
bandwidth problems.
(I can't get anything without gaps above 4 MSPS complex 16 bit, even with a 
straightforward dump to a ramdisk)
I would like to be able to get only 8 or 10 bit samples over the usb bus or only the real part of the complex signal (or the abs of the complex 
signal))

If you know any tricks to get the linux-usb driver to deliver more bandwith 
then I would also like to hear.
(I read that only the intel usb2 host-controller can deliver 32 MB/s)

I have looked in the usrp driver code but did't know where to look.

I would also really like to find a copy of specsheets and application notes of the microtune tuner in the tvrx. The pdfs seem to be removed of 
the microtune site.
(especially the gain-control and exact (if and second if) filter 
characteristics information for building a tvrx agc and videofilter)

greetings,
Martin