Re: [Discuss-gnuradio] UHD clock rate in the usrp e310 - release 4

[Martin Braun]

Gabriel,

I didn't realize you were also tx'ing. You won't be able to go to an
interpolation of 1024 on the Tx side.

M

On 04/16/2016 09:37 AM, Gabriel Pechiarovich wrote:
> Hi I just tried your suggestion and it was ok for the RX side, but in
> the Tx side the decimation wont go up to 1024, it only decimates up to 512, 
> 
> -- Asking for clock rate 16.384 MHz
> -- Actually got clock rate 16.384 MHz
> -- Performing timer loopback test... pass
> -- Performing timer loopback test... pass
> 
> UHD Warning:
>     The hardware does not support the requested TX sample rate:
>     Target sample rate: 0.016000 MSps
>     Actual sample rate: 0.032000 MSps
> 
> so is this locked for security or something, or the hardware simple
> doesn't have the capabilities?
> 
> 
> 
> 2016-04-07 5:33 GMT+00:00 Martin Braun <address@hidden
> <mailto:address@hidden>>:
> 
>     On 04/06/2016 10:26 PM, Martin Braun wrote:
>     > On the release 4 image, you can't do that. But you can set the clock to
>     > 16 MHz and use a decimation of 1000. Or you can use a clock rate of
>     > 16384e3 and a decimation of 1024, for a better decimation filter 
> response.
> 
>     ...they'll probably be about the same, as the same number of halfbands
>     will be active. But the point is, you can't go below 10 MHz MCR on
>     release 4, and not above decimation 1024.
> 
>     Cheers,
>     M
>     >
>     > Cheers,
>     > Martin
>     >
>     > On 04/06/2016 06:11 PM, Gabriel Pechiarovich wrote:
>     >> Hi, thanks for your answeri wasn't able to answer earlier.
>     >>
>     >> I was aiming to a 8MHz clock rate in order to use the DDC and get a
>     >> 16000 sample rate.
>     >> So i think i was misunderstood.
>     >>
>     >> Thank you very much
>     >> Gabriel
>     >>
>     >>
>     >> 2016-03-31 13:25 GMT-05:00 Martin Braun <address@hidden
>     <mailto:address@hidden>
>     >> <mailto:address@hidden <mailto:address@hidden>>>:
>     >>
>     >>     On the release 4 image, you can't set the clock speed under
>     10 MHz.
>     >>     However, you can use a DDC (which is built in and
>     automatically used).
>     >>     Simply set the clock rate to 32 MHz (or 16 MHz if this is
>     MIMO) and the
>     >>     sample rate to 8 MHz.
>     >>
>     >>     Cheers,
>     >>     Martin
>     >>
>     >>     On 03/30/2016 05:02 PM, Gabriel Pechiarovich wrote:
>     >>     > Hi all,
>     >>     > I've developed a flowgraph wich includes  a qpsk modulator
>     and and
>     >>     audio
>     >>     > encoder, I used to run it in the E310 using the first release
>     >>     > (http://files.ettus.com/e3xx_images/e3xx-release-001/) and now
>     >>     trying to
>     >>     > use the release 4.
>     >>     >
>     >>     > The problem is:
>     >>     > in the UHD sink and source the clock rate was set to 8e6
>     Hz, and it
>     >>     > worked fine, in the release 1, but in the relese 4 the
>     Clock rate wont
>     >>     > go lower than 10e6 Hz, so i cant archive the same results.
>     >>     >
>     >>     > Any idea how to force the use of 8MHz as the clock rate
>     using the
>     >>     release4
>     >>     >
>     >>     > Thank you very much
>     >>     > Gabriel Pechiarovich Salas
>     >>     >
>     >>     >
>     >>     >
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>     >>
>     >> --
>     >> Gabriel Pechiarovich Salas
>     >> Red Dragon Games
>     >> Designers and game developers
>     >
> 
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> 
> 
> -- 
> Gabriel Pechiarovich Salas
> Red Dragon Games
> Designers and game developers