Re: [USRP-users] IQ Calibration - CPU Performance Impact?

2018-06-07 Thread Dave NotTelling via USRP-users 
Derek,
 I'm very happy to hear that it's the tiniest of additional overhead!

Thanks!

On Thu, Jun 7, 2018 at 2:32 PM Derek Kozel  wrote:

> Dave,
>
> It is most tunes (as often as needed when changing the frequency would
> change the IQ correction value). The overhead is, I believe, just a single
> write and thus completely inconsequential when compared to the usual length
> of synthesizer SPI writes and switch selection that tuning can cause.
>
> Regards,
> Derek
>
> On Thu, Jun 7, 2018 at 7:08 PM, Dave NotTelling via USRP-users <
> usrp-users@lists.ettus.com> wrote:
>
>> Robin,
>>  Thanks for your feedback!
>>
>> Marcus,
>>  And that overhead is just on the initial tune, or for all tunes?  I
>> do mostly timed commands, so should I allow for a little more time before
>> the deadline to send the timed command out?
>>
>> Thanks all!
>>
>> On Thu, Jun 7, 2018 at 1:56 PM Marcus D. Leech via USRP-users <
>> usrp-users@lists.ettus.com> wrote:
>>
>>> On 06/07/2018 01:04 PM, Dave NotTelling via USRP-users wrote:
>>> > Is there a processing requirement impact to using the calibration CSV
>>> > file?  Does using the cal data have any impact on tuning time for the
>>> > radio itself?
>>> >
>>> > Thanks!
>>> >
>>> The calibration values are stuffed into some machinery in the FPGA when
>>> tuning happens.  So, there's a little extra command-channel overhead.
>>>
>>>
>>>
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>>>
>>
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>>
>>
>
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Re: [USRP-users] IQ Calibration - CPU Performance Impact?

2018-06-07 Thread Derek Kozel via USRP-users 
Dave,

It is most tunes (as often as needed when changing the frequency would
change the IQ correction value). The overhead is, I believe, just a single
write and thus completely inconsequential when compared to the usual length
of synthesizer SPI writes and switch selection that tuning can cause.

Regards,
Derek

On Thu, Jun 7, 2018 at 7:08 PM, Dave NotTelling via USRP-users <
usrp-users@lists.ettus.com> wrote:

> Robin,
>  Thanks for your feedback!
>
> Marcus,
>  And that overhead is just on the initial tune, or for all tunes?  I
> do mostly timed commands, so should I allow for a little more time before
> the deadline to send the timed command out?
>
> Thanks all!
>
> On Thu, Jun 7, 2018 at 1:56 PM Marcus D. Leech via USRP-users <
> usrp-users@lists.ettus.com> wrote:
>
>> On 06/07/2018 01:04 PM, Dave NotTelling via USRP-users wrote:
>> > Is there a processing requirement impact to using the calibration CSV
>> > file?  Does using the cal data have any impact on tuning time for the
>> > radio itself?
>> >
>> > Thanks!
>> >
>> The calibration values are stuffed into some machinery in the FPGA when
>> tuning happens.  So, there's a little extra command-channel overhead.
>>
>>
>>
>> ___
>> USRP-users mailing list
>> USRP-users@lists.ettus.com
>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>>
>
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Re: [USRP-users] IQ Calibration - CPU Performance Impact?

2018-06-07 Thread Dave NotTelling via USRP-users 
Ian,
 Thank you very much!  That helps me out a lot!

-Dave

On Thu, Jun 7, 2018 at 2:17 PM Ian Buckley  wrote:

> Dave, from what I remember the overhead will be incurred each time a
> (re)tune takes you to a different line of the IQ imbalance table…you can
> see the granularity of that from simply looking in the CSV file.
> The overhead is very minor I suspect, we are talking about updating two
> integer coefficients (phase and mag correction) in setting regs for each TX
> and RX port.
> -Ian
>
> On Jun 7, 2018, at 11:08 AM, Dave NotTelling via USRP-users <
> usrp-users@lists.ettus.com> wrote:
>
> Robin,
>  Thanks for your feedback!
>
> Marcus,
>  And that overhead is just on the initial tune, or for all tunes?  I
> do mostly timed commands, so should I allow for a little more time before
> the deadline to send the timed command out?
>
> Thanks all!
>
> On Thu, Jun 7, 2018 at 1:56 PM Marcus D. Leech via USRP-users <
> usrp-users@lists.ettus.com> wrote:
>
>> On 06/07/2018 01:04 PM, Dave NotTelling via USRP-users wrote:
>> > Is there a processing requirement impact to using the calibration CSV
>> > file?  Does using the cal data have any impact on tuning time for the
>> > radio itself?
>> >
>> > Thanks!
>> >
>> The calibration values are stuffed into some machinery in the FPGA when
>> tuning happens.  So, there's a little extra command-channel overhead.
>>
>>
>>
>> ___
>> USRP-users mailing list
>> USRP-users@lists.ettus.com
>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>>
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>
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Re: [USRP-users] IQ Calibration - CPU Performance Impact?

2018-06-07 Thread Ian Buckley via USRP-users 
Dave, from what I remember the overhead will be incurred each time a (re)tune 
takes you to a different line of the IQ imbalance table…you can see the 
granularity of that from simply looking in the CSV file.
The overhead is very minor I suspect, we are talking about updating two integer 
coefficients (phase and mag correction) in setting regs for each TX and RX port.
-Ian

> On Jun 7, 2018, at 11:08 AM, Dave NotTelling via USRP-users 
>  wrote:
> 
> Robin,
>  Thanks for your feedback!
> 
> Marcus,
>  And that overhead is just on the initial tune, or for all tunes?  I do 
> mostly timed commands, so should I allow for a little more time before the 
> deadline to send the timed command out?
> 
> Thanks all!
> 
> On Thu, Jun 7, 2018 at 1:56 PM Marcus D. Leech via USRP-users 
> mailto:usrp-users@lists.ettus.com>> wrote:
> On 06/07/2018 01:04 PM, Dave NotTelling via USRP-users wrote:
> > Is there a processing requirement impact to using the calibration CSV 
> > file?  Does using the cal data have any impact on tuning time for the 
> > radio itself?
> >
> > Thanks!
> >
> The calibration values are stuffed into some machinery in the FPGA when 
> tuning happens.  So, there's a little extra command-channel overhead.
> 
> 
> 
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Re: [USRP-users] IQ Calibration - CPU Performance Impact?

2018-06-07 Thread Dave NotTelling via USRP-users 
Robin,
 Thanks for your feedback!

Marcus,
 And that overhead is just on the initial tune, or for all tunes?  I do
mostly timed commands, so should I allow for a little more time before the
deadline to send the timed command out?

Thanks all!

On Thu, Jun 7, 2018 at 1:56 PM Marcus D. Leech via USRP-users <
usrp-users@lists.ettus.com> wrote:

> On 06/07/2018 01:04 PM, Dave NotTelling via USRP-users wrote:
> > Is there a processing requirement impact to using the calibration CSV
> > file?  Does using the cal data have any impact on tuning time for the
> > radio itself?
> >
> > Thanks!
> >
> The calibration values are stuffed into some machinery in the FPGA when
> tuning happens.  So, there's a little extra command-channel overhead.
>
>
>
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Re: [USRP-users] IQ Calibration - CPU Performance Impact?

2018-06-07 Thread Marcus D. Leech via USRP-users 

On 06/07/2018 01:04 PM, Dave NotTelling via USRP-users wrote:
Is there a processing requirement impact to using the calibration CSV 
file?  Does using the cal data have any impact on tuning time for the 
radio itself?


Thanks!

The calibration values are stuffed into some machinery in the FPGA when 
tuning happens.  So, there's a little extra command-channel overhead.




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Re: [USRP-users] IQ Calibration - CPU Performance Impact?

2018-06-07 Thread ROBIN TORTORA via USRP-users 
What I have noticed over the years is the only impact to tuning is the first 
time you tune, the file is read in and any disk IO is slow relatively speaking. 
 Subsequent tunes after the first are much faster and consistent :)

> On June 7, 2018 at 1:04 PM Dave NotTelling via USRP-users 
>  wrote:
> 
> Is there a processing requirement impact to using the calibration CSV 
> file?  Does using the cal data have any impact on tuning time for the radio 
> itself?
> 
> Thanks!
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> 
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