RE: [Discuss-gnuradio] I and Q samples out of FPGA receive chain

[Nirali Patel]

I believe I am enabling the appropriate oe registers using the following
commands
u = usrp.source_c(0,decim_rate=8,fpga_filename="mytestfile.rbf")
subdev = usrp.selected_subdev(u,(1,0))  # for getting signals from slot B
TV_RX
u._write_oe(0,0xffff,oxffff)            # for enabling A side Basic RX
u._write_fpga_reg(FR_DEBUG_EN, bmFR_DEBUG_EN_RX_A)

However, I am perplexed as to why bb_rx_i0 or bb_rx_q0 do not seem to
toggle. When I connect ddc0_in_i signals I can see them toggling. I must be
doing something really stupid because the rbf file I generated works well
with a standard example like usrp_fft.py. So the data path from the ADC to
the USB is working well. But somehow I am not able to tap into the I and Q
signals out of the receive_chain and see them toggling. 

In the usrp_std.v file what signals do you recommend to look at the 16 bits
I and Q out of the HB filter of the receive_chain? 
Thanks again for you time and help.
Nirali 

> -----Original Message-----
> From: Johnathan Corgan [mailto:address@hidden
> Sent: Friday, November 02, 2007 11:56 AM
> To: Nirali Patel
> Cc: address@hidden
> Subject: Re: [Discuss-gnuradio] I and Q samples out of FPGA receive chain
> 
> Nirali Patel wrote:
> 
> > However I do not see any outputs when I connect these signals to the
> > debug pins using debug_0(bb_rx_q0),.debug_1(bb_rx_i0).
> 
> When routing signals through the master_controller debug ports, you'll
> need to (on the host at runtime) enable the debug output register, and
> set the IO pins as outputs.
> 
> HOWEVER--don't EVER do this unless you are using a BasicRX/TX or LFRX/TX
> board in the slots.  You can damage the daughterboard, USRP FPGA, or
> both otherwise.
> 
> --
> Johnathan Corgan
> Corgan Enterprises LLC
> http://corganenterprises.com