Re: Re[4]: LF: Is this frequency locking enough for EbNaut?

[Andy Talbot <andy.g4jnt@gmail.com>]

Difficult one to test for.  You'd have to be running a fully locked
system, or at least everything running from one reference clock
supplied to everything, then continuously monitor phase and look for
phase slippage - perhaps.   If samples were missed and they weren't
accounted for, that would introduce a phase shift , but only on a
non-zero baseband tuned signal.   Needs some thought

Andy


On 7 December 2015 at 11:29, Chris Wilson <chris@chriswilson.tv> wrote:
> Hello Andy,
>
> Sunday, December 6, 2015
>
>
> So  how  would  I test for these "slippages" or even recognize if they
> were occurring  Andy?
>
>
> What  sound cards are you EbNauters using that might have good Win7 64
> bit drivers??
>
> Thanks.
>
>
>> Be careful, it 'may' be OK, but I have heard that slippages can occurt.
>> Due to difference in sample rates between the USB itself and 12MHz
>> clock of the chip,  when using USB isochronos mode (used for time
>> dependent data like audio), it can slip occasional samples as the
>> clocks slide past each other.
>
>> I have used that chip, or at least a close relation,  but never in a
>> synchronous manner - so it may be worth testing see if slippages do
>> occur.
>
>> Andy  G4JNT
>
>
>
>
>
>
>
>
>
> --
> Best regards,
>  Chris  2E0ILY                          mailto:chris@chriswilson.tv
>
>