Re: [Discuss-gnuradio] I&Q on same or separate channels?

[George Nychis]

Brian Padalino wrote:
> Looking at the flow, each channel has a fifo1kx16 each, which you are
> presumably going to make a fifo512x32?
>
> I have a feeling you're going to have to modify your packet_builder as
> well.  The packet_builder looks at the channel FIFOs sequentially and
> builds a packet based on that FIFO.  You need to add a state or some
> extra logic in the FORWARD state that will FORWARD_I then FORWARD_Q
> from the input chan_fifodata.
>
> That seems to be the only place where it's used, so if you make your
> interface 32 bits instead of 16, and make the change to the FSM, you
> should be interleaving happily.
>
> Good luck with your modification.

Taking a look at how the legacy code does it...
http://gnuradio.org/trac/browser/gnuradio/branches/developers/gnychis/inband/usrp/fpga/sdr_lib/rx_buffer.v#L137

What do you think about adopting this method?  It's using a 16-bit wide 
FIFO still and just alternating between which channel it is feeding in 
to the FIFO using a channel counter (store_next).  In our case, we would 
just alternate between channel 0 and channel 1 to have 1 full data 
channel, for now. Unless there is something different in our case that 
I'm unaware of.  This would prevent us from having to change the 
megacells and re-write some of the other state machines.

- George