Re: [Discuss-gnuradio] FPGA firmware

[Eric Blossom]

On Tue, Aug 28, 2007 at 11:02:25PM +0200, Dominik Auras wrote:
> Hi!
> 
> Am I right to state that the fpga firmware is configured as followed:
> 
> Tx chain (0 to 2 possible)
> - NCO fine+coarse on Analog Devices Chip
> - low-pass 4x interpolation on AD-Chip
> - CIC interpolation filters, separate for I- and Q-Data
> 
> Especially:
> Cordic turned off, internal DUC (duc.v) turned off?

Correct.

> And RX Chain (0 to 4 possible)
> - Cordic for downconversion
> - CIC decimator per I- and Q-Stream
> - Halfbandfilter, after CIC, per I/Q-Stream

The half-band is missing from the 4 DDC version because of resource
constraints. 

> Also:
> DDC not used? (I mean, ddc.v)

Correct.

> Low-pass decimation filter on AD-Chip disabled.

Correct.

> I wonder if http://gnuradio.org/trac/wiki/UsrpRfxDiagrams is still correct.

yes, with the annotations.

> Greetings
> Dominik

Eric