On Mon, Mar 17, 2008 at 08:59:54PM -0700, Bill Stevenson wrote:
> Hello, everyone
>
> I dug up the wfm_rcv_gui.py example file in order to penetrate the
> principle of GNURadio. But I have 2 questions about it:
>
> 1, there is a digital downconverter at the receiver, the function of
> down converting the signal is performed by the FPGA or the software
> on PC?
There are two downconverions, one in the RF daughterboard, and one in
the DDC in the FPGA.
See http://gnuradio.org/trac/wiki/UsrpRfxDiagrams
> 2, if it is done by FPGA, how is the code transmitted to the FPGA? I
> mean, the code should be written using VHDL or Verilog, but now the
> code is compiled using Python! How is this transformation done?
If you take a look through the downloaded source code, you'll find the
verilog for the FPGA in usrp/fpga.
The firmware for the FX2 (usb interface chip) and the FPGA
configuration are loaded behind the scenes by the usrp library which
is invoked by usrp.sink*/source
Eric