Thanks Sam, Marcus,

The approach with timed commands indeed seems a lot more manageable. We're 
gonna try this first.

________________________________
From: Marcus D Leech <[email protected]>
Sent: Wednesday, May 27, 2020 7:07 PM
To: Sam Reiter
Cc: Haberleitner David - S1810567006; [email protected]
Subject: Re: [USRP-users] X310: control frontend with custom RFNoC blocks

I don't know that much about RFNOC structure, but the tuning latency is 
dominated by SPI transaction time, and the tome it takes the chips to tune to a 
new frequency.

That is much larger than the host and Ethernet side of things.

Doing what the host does to tune the chips (a bunch of math to set various 
registers) in the FPGA will consume a fair amount of real estate on the FPGA.

Sent from my iPhone

On May 27, 2020, at 12:38 PM, Sam Reiter via USRP-users 
<[email protected]> wrote:

?
David,

Do you know ahead of time what the frequency sweeps are going to be, or do you 
need to have your RFNoC block creating and scheduling them dynamically?

If you know your frequency sweep list ahead of time, a much easier technique 
would be for you to send your tune requests from host to radio as timed 
commands. This way you can queue up hops that will execute at a precise 
timestamp in your data  stream. Depending on the length of your frequency list, 
you may need to expand the size of the command queue in your FPGA image, but 
that would be a much more manageable task than creating a block that constructs 
and issues commands.

-Sam

On Wed, May 27, 2020 at 7:04 AM Haberleitner David - S1810567006 via USRP-users 
<[email protected]<mailto:[email protected]>> wrote:

Hi everyone,


for our project we would like to control frontend settings directly from the 
hardware to perform fast frequency sweeps.
Is there a way to do that?


>From out research it seems that the frontend chips (UBX160 in our case) are 
>controlled via a SPI register in the Radio-NoC block. But we haven't figured 
>out how to control this register from our custom block (via the Command 
>Interface?).


Thanks,
David

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